Field of the Invention
[0001] This invention relates to bicyclic compounds useful as glycoprotein IIb/IIIa antagonists
for the prevention of thrombosis.
Background of the Invention
[0002] The most prevalent vascular disease states are related to platelet dependent narrowing
of the blood supply such as atherosclerosis and arteriosclerosis, acute myocardial
infarction, chronic stable angina, unstable angina, transient ischemic attacks and
strokes, peripheral vascular disease, arterial thrombosis, preeclampsia, embolism,
restenosis or abrupt closure following angioplasty, carotid endarterectomy, anastomosis
of vascular grafts, and etc. These conditions represent a variety of disorders thought
to be initiated by platelet activation on vessel walls. Platelet adhesion and aggregation
is believed to be an important part of thrombus formation. This activity is mediated
by a number of platelet adhesive glycoproteins. The binding sites for fibrinogen,
fibronectin and other clotting factors have been located on the platelet membrane
glycoprotein complex IIb/IIIa. When a platelet is activated by an agonist such as
thrombin the GPIIb/IIIa binding site becomes available to fibrinogen, eventually resulting
in platelet aggregation and clot formation.
[0003] Heretofore it has been proposed to block these thrombus formation sites by the use
of various therapeutic agents.
[0004] U.S. Patent No. 5,064,814 teaches N-amidinopiperidine carboxyl cyclic amino acid
derivatives as antithrombotic agents.
[0005] U.S. Patent 5,039,805 teaches various benzoic acid and phenylacetic acid derivatives
for the inhibition of the binding of fibrinogen to the fibrinogen receptor, glycoprotein
IIb/IIIa.
[0006] Seven membered ring containing bicyclic compounds are taught to be fibrinogen antagonists
in PCT International patent application WO 93/00095.
[0007] EP 456835 describes bicyclic compounds having fused six membered rings (quinazoline-3-alkanoic
acid derivates) which are reported to have an inhibitory effect on platelet aggregation.
[0008] PCT International patent application WO 93/08174 describes nonpeptidyl integrin inhibitors
which are bicyclic 6 and 7 membered fused ring systems which have therapeutic applications
in diseases for which blocking platelet aggregation is indicated.
[0009] Patent Application WO94/12478 describes the preparation of 6,5-bicyclic compounds
stated to be effective for inhibiting platelet aggregation.
[0010] Patent Application WO94/08962 describes the preparation of 6,5-bicyclic compounds
stated to be effective for inhibiting platelet aggregation.
[0011] British Patent application GB 2276384 describes novel oxoquinazolin derivatives stated
to have fibrinogen receptor antagonistic activity.
[0012] The article, "From Peptide to Non-Peptide. 1. The Elucidation of a Bioactive Conformation
of the arginine-glycine-aspartic Acid Recognition Sequence", by Robert S. McDowell,
et. al., J. Am. Chem. Soc. 1994, 116, pp. 5069-5076, describes design of non-peptidal
inhibitors of fibrinogen-glycoprotein IIb/IIIa binding.
[0013] The publication, "Chapter 9. Glycoprotein IIbIIIa Antagonists" by Brent K. Blackburn
and Thomas R. Gadek, Annual Reports in Medicinal Chemistry -28, Section II - Cardiovascular,
and Pulmonary Agents, pp 79-88, 1993, publ. by Academic Pres, Inc., describes non-peptides
as antagonists of GPIIbIIIa/fibrinogen interaction.
[0014] The article, "From Peptide to Non-Peptide. 2. The de Novo Design of Potent, Non-Peptidal
Inhibitors of Platelet Aggregation Based on a Benzodiazepinedione Scaffold", by Robert
S. MoDowell, et. al., J. Am. Chem. Soc. 1994, 116, pp 5077-5083, describes benzodiazepinedione
which are inhibitors of platelet aggregation.
[0015] Quinoline compounds have been recited in the patent literature for a variety of medicinal
uses. For example, European Patent Application 0 315 399; U.S. Patent No. 5,041,453;
PCT Patent Application WO 89/04303, and PCT Patent Application WO 89/04304 describe
quinoline derivatives useful as lipoxygenase inhibitors and/or leukotriene antagonists
possessing anti-inflammatory and anti-allergic properties. These compounds must contain
three aromatic rings, each interrupted with oxygen, or sulfur, and possibly other
groups
[0016] The document EP-A-0635492 describes bicyclic compounds based on isoquinoline, isoquinolone,
tetrahydronaphtalene, dihydronaphtalene and tetralone, which are useful in the inhibition
of platelet aggregation.
[0017] The document EP-A-0655439 discloses 5,6 fused ring bicyclic compounds based on indoles,
benzofurans and benzothiophenes, which are useful in inhibition of platelet aggregation.
[0018] The document WO-A-93/12074 discloses peptide mimetic compounds, which are useful
in inhibiting platelet aggregation.
[0019] There is a need in the area of cardiovascular and cerebrovascular therapeutics for
alternative agents which can be used in the prevention and treatment of thrombi.
[0020] It is a discovery of this invention that certain novel bicyclic compounds block the
GPIIb/IIIa fibrinogen receptor, thereby inhibiting platelet aggregation and subsequent
thrombus formation. Pharmaceutical formulations containing the bicyclic compounds
of this invention inhibit aggregation and are useful for the prophylaxis and treatment
of thrombogenic diseases, such as myocardial infarction, angina, stroke, peripheral
arterial disease, disseminated intravascular coagulation and venous thrombosis.
Summary of the Invention
[0021] The present invention is a novel bicyclic compound having a nucleus formed from two
fused six membered rings, A and B, represented by the formula (I), as hereinafter
defined, and all pharmaceutically acceptable salts, solvates and prodrug derivatives
thereof:

[0022] Another aspect of the invention is a pharmaceutical formulation containing the novel
bicyclic compounds of the invention.
[0023] Another aspect of the invention is a method of inhibiting platelet aggregation, inhibiting
fibrinogen binding, or preventing thrombosis by administering to a mammal the bicyclic
compounds of the invention.
[0024] Another aspect of this invention is a method of treating a human to alleviate the
pathological effects of atherosclerosis and arteriosclerosis, acute myocardial infarction,
chronic stable angina, unstable angina, transient ischemic attacks and strokes, peripheral
vascular disease, arterial thrombosis, preeclampsia, embolism, restenosis following
angioplasty, carotid endarterectomy, and anastomosis of vascular grafts; wherein the
method comprises administering to said human the novel bicyclic compound of this invention.
Detailed Description of the Invention
[0025] The term "alkyl" used herein refers to a monovalent straight or branched chain radical
of from one to ten carbon atoms, including, but not limited to methyl, ethyl, n-propyl,
isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, and the like.
[0026] The term, "halosubstituted alkyl" as used herein refers to an alkyl group as just
defined, substituted by one, two or three halogen atoms selected from fluorine, chlorine,
bromine, and iodine. Examples of such groups include chloromethyl, bromoethyl, trifluoromethyl,
and the like.
[0027] The term, "aryl", when used alone means a homocyclic aromatic radical whether or
not fused. Preferred aryl groups include phenyl, napthyl, biphenyl, phenanthrenyl,
naphthacenyl, and the like.
[0028] The term, "substituted aryl", denotes an aryl group substituted with one, two, or
three substituents chosen from halogen, hydroxy, protected hydroxy, cyano, nitro,
C
1-C
10 alkyl, C
1-C
10 alkoxy, trifluoromethyl, amino, aminomethyl, and the like. Examples of such groups
are 4-chlorophenyl, 2-methylphenyl, 3-methyl-4-hydroxyphenyl, and 3-ethoxyphenyl.
[0029] The term, "arylalkyl", means one, two or three aryl groups having the number of carbon
atoms designated, appended to an alkyl radical having the number of carbon atoms designated.
A typical arylalkyl group is the benzyl group.
[0030] The term "alkenyl" as used herein refers to a monovalent straight or branched chain
radical of from two to six carbon atoms containing a carbon double bond including,
but not limited to, 1-propenyl, 2-propenyl, 2-methyl-1-propenyl, 1-butenyl, 2-butenyl
and the like.
[0031] The term, "alkylene" as used herein refers to a divalent straight or branched chain
group of from one to ten carbon atoms, including but not limited to, -CH
2-, -(CH
2)
2-. -(CH
2)
3-, -CH(CH
3)-, -CH(C
2H
5)-, -CH(CH
3)CH
2-, and the like.
[0032] The term "alkenylene" as used herein refers to a divalent straight or branched chain
group of from two to ten carbon atoms containing a carbon-carbon double bond, including
but not limited to, -CH=CH-, -C(CH
3)=CH-, CH=CH-CH
2-, -CH=C(CH
3)-CH
2-, -CH
2CH(CH=CH
2)CH
2, and the like.
[0033] The term, "alkynylene" as used herein refers to a divalent straight or branched chain
group of from two to ten carbon atoms containing a carbon-carbon triple bond, including
but not limited to,

and the like.
[0034] The term, "amidino" refers to the radical having the structural formula;

[0035] The term, "basic radical" refers to an organic radical which is a proton acceptor.
Illustrative basic radicals are amidino, piperidyl, guanidino, and amino.
[0036] The term, "basic group" refers to an organic group containing one or more basic radicals.
A basic group may comprise only an basic radical.
[0037] The term, "non-interfering organc radical" is any organic substituent present on
the bicyclic compound of formula (I) which is not deleterious to its efficacy as a
Glycoprotein IIb/IIIa antagonist.
[0039] The term, "acidic group" is an organic group containing one or more acid radicals.
An acidic group may comprise only an acid radical.
Compounds of the Invention:
[0040] Compounds of this invention have the general formula (I) shown below:

and all pharmaceutically acceptable salts, solvates and prodrug derivatives thereof.
[0041] The bicyclic nucleus of (I) is formed from the fusion of two six membered rings "A"
and "B" having carbon bridging atoms. The dashed lines in the structural formula (I)
signify the optional presence of an additional bond, that is, unsaturation that will
lend aromatic character to the ring structure. It will be understood that the bridging
carbon atoms will either be unsubstituted or substituted (with hydrogen) depending
on the degree of unsaturation in the bicyclic ring system. The A ring atoms A
1, A
2, A
3, and A
4 and the B ring atoms B
1, B
2, B
3, B
4 of formula (I) are independently selected from carbon, oxygen, sulfur, and nitrogen,
with the proviso that at least two of B
1, B
2, B
3, B
4 are carbon. More precisely, A
1, A
3, and A
4 are independently selected from carbon, oxygen, sulfur, and nitrogen and A
2 is independently selected from carbon or nitrogen, provided that A
2 have an unsatisfied bond if A
2 is N and provided that at least two of A
1, A
2, A
3, and A
4 are carbon. Correspondingly, B
1, B
2, and B
4 are independently selected from carbon, oxygen, sulfur, and nitrogen and B
3 is independently selected from carbon or nitrogen and provided that B
3 have an unsatisfied bond if B
3 is N and provided that at least two of B
1, B
2, B
3 and B
4 are carbon.
[0043] The nuclei depicted by formulae (1) to (16) supra., and (17) to (30) infra., have
the A and B ring atom numberings and corresponding substituent placements as shown
in (1) above. For example, the nuclei (Imm) and (Ipp).

would yield different products within the scope of formula (I).
[0049] Other bicyclic nuclei ring substituted with =O suitable for forming the compounds
of formula (I) are represented by the formulae (28) through (30) below:

[0051] The most preferred nuclei for the compounds of this invention are isoquinoline, isoquinolone,
naphthalene, tetrahydronapthalene, tetralone, dihydronaphthalene, and benzopyran.
[0052] The substituent R
3 is an acidic group or a pharmaceutically acceptable salt or solvate thereof, (or
a prodrug derivative of said acidic group) and preferably is an acidic group containing
carboxyl functionality. The R
3 group may be the sole substituent of ring atom B
3. Alternatively, when the B
3 atom can accept two bonds, these bonds may be satisfied by a double bond on the R
3 group (with the R
3 double bond attached directly to the B ring of formula I), or a second R
3 group, or a second group selected from hydrogen, C
1-C
10 alkyl, C
1-C
10 halosubstituted alkyl, C
2-C
10 alkenyl, C
2-C
10 alkynyl, C
3-C
10 cycloalkyl, aryl, C
7-C
12 aralkyl, hydroxy, C
1-C
10 alkoxy, C
1-C
10 aralkoxy, carboxy, acyl, cyano, halo, nitro, and sulfo.
[0054] The substituents R
0 are non-interfering organic radicals and are the same or different on each atom B
1, B
2, and B
4 and the same or different between atoms B
1, B
2, and B
4 and are independently selected from hydrogen, C
1-C
10 alkyl, C
1-C
10 halosubstituted alkyl, C
2-C
10 alkenyl, C
2-C
10 alkynyl, C
3-C
10 cycloalkyl, aryl, C
6-C
12 arylalkyl, hydroxy, C
1-C
10 alkoxy, C
6-C
12 arylalkoxy, amino, substituted amino, carbamoyl, carboxy, acyl, cyano, halo, nitro,
sulfo; with the proviso that only one of B
1, B
2, and B
4 may also be substituted with =O or =S.
[0055] The number, n, of R
0 substituents attached to the atoms B
1, B
2, and B
4 of the B ring is an integer from 0 to 6 and depends on the sum of the number of unsatisfied
bonds present in the individual atoms B
1, B
2, and B
4. Typically, n will be from 2 to 6 for most of the compounds of the invention. Thus,
for example, where the B ring is saturated, B
2 is oxygen, and B
1 and B
4 are carbon, then no R
0 substituent will be present on atom B
2 as shown in structural formula (Iq) below:

For B rings having unsaturation, the number of unsatisfied bonds present in the individual
atoms B
1, B
2, and B
4 is decreased and the number of R
0 substituents required is correspondingly less. Thus, for example, where the 3 ring
is unsaturated, B
2 is nitrogen, and B
1 and B
4 are carbon, then no R
0 substituent will be present on B
2 as shown in structural formula (Ir) below:

[0056] The A ring atoms A
1, A
2, A
3, and A
4 are independently selected from carbon, oxygen, sulfur, and nitrogen, with the proviso
that at least two of A
1, A
2, A
3, and A
4 are carbon. The substituents R
10 are the same or different on each atom A
1, A
3, and A
4 and the same or different between atoms A
1, A
3 and A
4, and are independently selected from hydrogen, C
1-C
10 alkyl, C
1-C
10 halosubstituted alkyl, C
2-C
10 alkenyl, C
2-C
10 alkynyl, C
3-C
10 cycloalkyl, aryl, C
6-C
12 arylalkyl, hydroxy, alkoxy, C
6-C
12 arylalkoxy, carboxy, acyl, cyano, halo, nitro, and sulfo; with the proviso that only
one of A
1, A
3, and A
4 may also be substituted with =O or =S when two sites are available for substitution
on a single atom (viz., when one or more of the dashed lines in the A ring of Formula
I are absent and an A atom is carbon).
[0057] The number, m, of R
10 substituents attached to the atoms A
1, A
3, and A
4 of the A ring is an integer from 0 to 6 and depends on the sum of the number of unsatisfied
bonds present in the individual atoms A
1, A
3, and A
4 in a manner analogous to the substitution of R
0 groups on the B ring as described above. Typically, n will be from 2 to 6 for most
of the compounds of the invention. The atom, A
2, of the A ring is substituted by linking group -(L)- alone when A
2 has only one unsatisfied bond, however, when A
2 has two unsatisfied bonds the second bond may be satisfied by a group selected from
hydrogen, alkyl, halosubstituted C
1-C
10 alkyl, C
2-C
10 alkenyl, C
2-C
10 alkynyl, C
3-C
10 cycloalkyl, aryl, C
7-C
12 arylalkyl, hydroxy, C
1-C
10 alkoxy, C
7-C
12 arylalkoxy, acyl, cyano, halo, nitro, sulfo, and a basic group.
[0058] The linking group -(L)- attached to the A
2 atom of the A ring and is (i) a bond, or (ii) a divalent substituted or unsubstituted
chain of from 1 to 10 atoms (viz., there are 1 to 10 atoms in the chain between the
linking divalent bonds, with all other atoms pendent from these chain atoms). For
example, when -(L)- is a bond the compound of the invention may have the structural
formula Is as follows:

Alternatively, when -(L)- is the linking group

the compound of the invention may have the structural formula (It) as follows:

Alkylene, alkenylene and alkynylene groups are suitable as linking groups. Preferred
linking groups have 1 to 4 chain atoms and correspond to the general formulae:

or

or

or

where Z
1, Z
2, Z
3, and Z
4 are atoms selected from the group consisting of carbon, nitrogen, sulfur, and oxygen.
Linking groups containing three chain atoms such as,

where R is hydrogen or alkyl, may be used.
[0060] Asymmetric linkers, for example, the linkers

or

may be reversed in their point of attachment between the nucleus A ring and the basic
group Q, as depicted in formulae (Iu) and (Iv) below:

[0061] The substituent Q of formula (I) is a basic group. A basic group contains one or
more basic radicals, Q
1.
[0062] Suitable basic radicals contain one or more nitrogen atoms and include amino, imino,
amidino, N-alkylamidines, N,N'-dialkyamidines, N-arylamidines, aminomethyleneamino,
iminomethylamino, guanidino, aminoguanidino, alkylamino, dialkylamino, trialkylamino,
alkylideneamino, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, pyrazinyl, pyrimidinyl,
indolizinyl, isoindolyl, 3H-indolyl, indolyl, 1H-indazolyl, purinyl, 4H-quinolizinyl,
isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl,
amide, thioamide, benzamidino, pteridinyl, 4aH-carbozolyl, carbozolyl, beta-carbolinyl,
phenanthridinyl, acridinyl, pyrimidinyl, phenanthrolinyl, phenazinyl, phenarsazinyl,
phenothiazinyl, pyrrolinyl, imidazolidinyl, imidazolinyl, pyrazolidinyl, pyrazolinyl,
piperidyl, piperazinyl, indolinyl, isoindolinyl, quinuclidinyl, morpholinyl, or any
of the preceding substituted with amino, imino, amidino, aminomethyleneamino, iminomethylamino,
guanidino, alkylamino, dialkylamino, trialkylamino, tetrahydroisoquinoline, dihydrosioindole,
alkylideneamino groups or a group represented by the formula;

Preferred basic radicals are selected from amino, piperidyl, guanidino, and amidino.
The most preferred basic radicals are amidino and piperidyl represented by the formulae;

[0063] The basic group Q may have the form of a basic radical (such as Q
1 on formula Iw, infra.) pendant on a cyclic ring. Thus, Q, the basic group, may comprise
two parts, namely, (i) one or more basic radicals, Q
1 and (ii) a cyclic group, "D", having from 5 to 8 ring atoms. The D ring attached
to the A
2 atom of the A ring of the bicyclic nucleus throuth the linking group -(L)- as shown
in formula (I), supra. The D ring may also have substituents R
20 which are selected from chlorine, fluorine or non-interfering organic radicals. The
R
20 substituents may be t in number, where t is an integer from zero to the number of
unsatisfied bonds in the D ring. The basic radical Q
1 attaches to the D ring in the manner shown in formula (Iw) below:

[0064] Suitable D rings are formed from a nucleus selected from the group consisting of;
benzene, cycloheptadiene, cycloheptatriene, cycloheptane, cyclohexane, cyclohexene,
cyclohexadiene, cycloheptene, cyclooctadiene, cyclooctane, cyclooctatetraene, cyclooctene,
cyclopentane, cyclopentene, imidazole, isooxazole, morpholine, oxazole, piperazine,
piperidine, pyrazine, pyrazole, pyridine, pyrimidine, pyrrole, pyrrolidine, pyrroline,
tetrahydropyridine, tetrahydropyrimidine, 1H-tetrazole, thiazolidine, thiazole, thiopyran,
1,3,5-triazine, 1,2,3-triazole, 1,2,4-triazole, dihydrofuran, dihydropyran, dioxane,
dioxepin, dioxolane, furan, oxocane, tetrahydrofuran, tetrahydropyran, thiophene,
and tetrahydrothiophene.
[0065] General formula (Ix) for the preferred compounds of the invention having a basic
radical attached to a cyclic ring of 5 to 8 atoms is shown below:

wherein;
A1, A3, A4 are independently selected from carbon, oxygen, sulfur, and nitrogen;
A2 is independently selected from carbon or nitrogen, provided that A2 have an unsatisfied bond if A2 is N and provided that at least two of A1, A2, A3, and A4 are carbon;
B1, B2, B4 are independently selected from carbon, oxygen, sulfur, and nitrogen;
B3 is independently selected from carbon or nitrogen, provided that B3 have an unsatisfied bond if B3 is N and provided that at least two of B1, B2, B3, B4 are carbon;
R3 is an acidic group containing one or more acid radicals;
n is a number from 0 to 6;
R0 is the same or different and is independently selected from hydrogen, alkyl, halosubstituted
alkyl, alkenyl, alkynyl, cycloalkyl, aryl, arylalkyl, hydroxy, alkoxy, aralkoxy, amino,
substituted amino, carbamoyl, carboxy, acyl, cyano, halo, nitro, sulfo, =O, or =S;
with the proviso that if R0 is =0 or =S, then only one of B1, B2, B3, and B4 may be nitrogen;
m is a number from 0 to 6;
R10 is the same or different and is independently selected from hydrogen, alkyl, halosubstituted
alkyl, alkenyl, alkynyl, cycloalkyl, aryl, arylalkyl, hydroxy, alkoxy, aralkoxy, carboxy,
acyl, cyano, halo, nitro, sulfo, =O, and =S; with the proviso that only one R10 may be =0 or =S;
t is a number from 0 to 3;
R20 is the same or different and is independently selected from hydrogen, halogen, alkyl,
halosubstituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl, arylalkyl, hydroxy, alkoxy,
aralkoxy, carboxy, acyl, cyano, halo, nitro, sulfo;
linking group -(L)- is a bond or a divalent substituted or unsubstituted chain of
from 1 to 10 atoms selected from the group consisting of carbon, nitrogen, sulfur,
and oxygen; and;
D is a ring formed from 5 to 8 ring atoms and said ring atoms are independently selected
from carbon, nitrogen, oxygen, or sulfur, with the proviso that at least two D ring
atoms are carbon;
w is an integer from 1 to 3;
Q1 is a basic radical.
[0067] A preferred basic group Q has a six membered D ring as represented by formula (Iai)
below;

where p is an integer from 0 to 8, as for example, the specific Q groups:

[0068] A preferred embodiment of the compound of the invention is represented by formula
II, below:

In formula II the basic group on atom A
2 of the nucleus has two parts, namely, (i) a six membered ring, D, which attaches
to linking group -(L)-, and (ii) basic radical(s), Q
1, (where w is an integer from 1 to 3) attached to the D ring. The basic radicals are
as previously defined.
[0069] Atoms D
2, D
3, D
4, D
5 and D
6 are independently selected from carbon, nitrogen, oxygen, or sulfur and atom D
1 is selected from carbon or nitrogen; with the proviso that at least two of D
1, D
2, D
3, D
4, D
5 and D
6 are carbon. Q
1 is a basic radical as previously defined. Preferred ring structures having pendant
Q
1 are those where atoms D
1, D
2, D
3, D
4, D
5 and D
6 form a cyclic ring selected from the group consisting of benzene, pyridine, piperidine,
1,2-piperazine, 1,3-piperazine, 1,4-piperazine, pyran, thiopyran, thiabenzene, cyclohexene,
and cyclohexane, with benzene being the most preferred.
[0070] A preferred basic radical Q
1 is an amidino radical.
[0071] The substituents R
20 are the same or different on each atom D
2, D
3, D
5, and D
6 and the same or different between atoms D
2, D
3, D
5, and D
6 and are non-interfering organic radicals independently selected from hydrogen, alkyl,
halosubstituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl, arylalkyl, hydroxy, alkoxy,
aralkoxy, amino, substituted amino, carbamoyl, carboxy, acyl, cyano, halo, nitro,
and sulfo. The number, p, of substituents R
20 is an integer from 0 to 8 depending on the sum of the number of unsatisfied bonds
present in the individual atoms D
2, D
3, D
5, and D
6.
[0072] Preferred compounds of this invention are based on benzamidine substituted isoquinoline,
isoquinolone, naphthalene, tetrahydronaphthalene, dihydronaphthalene, benzopyran,
and tetralone nuclei, as partially illustrated in formulae (III) through (IIIe) below:

where -(L)-, n, m, p, R
0, R
3, R
10 and R
20 are as previously defined. Most preferred are compounds where R
10 and R
20 are hydrogen and -(L)- has 2 carbon atoms.
[0073] Another preferred aspect of the invention is where the D ring is contains one or
more (preferably 1 or 2) substituents independently selected from chlorine or fluorine.
The chlorine and fluorine substituents may be added to any 5 to 8 membered D ring
described above. Illustrative compounds of the invention with substitution of six
membered D rings are shown in formulae (IV) to (IVb) below:

[0074] Without being bound by any theory of operation it is believed that the electron withdrawing
groups such as fluorine reduce the basicity of the basic group and enhance the oral
bioavailability of the compounds of the invention.
[0079] The compounds of the invention possess at least one acidic functional substituent
(viz., R
3 of Formula I) and, as such, are capable of forming salts. Representative pharmaceutically
acceptable salts, include but are not limited to, the alkali and alkaline earth salts
such as lithium, sodium, potassium, calcium, magnesium, aluminum and the like. Salts
are conveniently prepared from the free acid by treating the acid in solution with
a base or by exposing the acid to an anion exchange resin on the salt cycle.
[0080] Included within the definition of pharmaceutically acceptable salts are the relatively
non-toxic, inorganic and organic base addition salts of compounds of the present invention,
for example, ammonium, quaternary ammonium, and amine actions, derived from nitrogenous
bases of sufficient basicity to form salts with the compounds of this invention (see,
for example, S. M. Serge, et. al., "Pharmaceutical Salts," J. Phar. Sci., 66: 1-19
(1977)).
[0081] The basic portion of the compounds of the invention (viz., group Q of formula I and
group Q
1 of formula II) may be reacted with suitable organic or inorganic acids to form salts
of the invention. Representative salts include those selected from the group comprising;
acetate, benzenesulfonate, benzoate, bicarbonate, bisulfate, bitartrate, borate, camsylate,
carbonate, chloride, clavulanate, dihydrochloride, edetate, edisylate, estolate, esylate,
fumarate, gluceptate, gluconate, glutamate, glycollylarsanllate, hexylresorcinate,
hydrabamine, hydrobromide, hydrochloride, hydroxynaphthoate, iodide, isothionate,
lactate, lactobionate, laurate, malate, malseate, mandelate, mesylate, methylbromide,
methylnitrate, methylsulfate, mucate, napsylate, nitrate, oleate, oxalate, palmitate,
pantothenate, phosphate, polygalacturonate, salicylate, stearate, subacetate, succinate,
tannate, tartrate, tosylate, trifluoroacetate, trifluoromethane sulfonate, and valerate.
[0082] The compounds of the formula (I) can also be in the form of zwitterions, since they
contain both acidic and basic functionality and are capable of self-protonation.
[0083] Certain compounds of the invention possess one or more chiral centers and may thus
exist in optically active forms. Likewise, when the compounds contain an alkenyl or
alkenylene group there exists the possibility of
cis- and trans- isomeric forms of the compounds. The
R- and
S-isomers and mixtures thereof, including racemic mixtures as well as mixtures of
cis- and
trans- isomers, are contemplated by this invention. Additional asymmetric carbon atoms can
be present in a substituent group such as an alkyl group. All such isomers as well
as the mixtures thereof are intended to be included in the invention. If a particular
stereoisomer is desired, it can be prepared by methods well known in the art by using
stereospecific reactions with starting materials which contain the asymmetric centers
and are already resolved or, alternatively by methods which lead to mixtures of the
stereoisomers and subsequent resolution by known methods.
Prodrug Derivatives of Compounds of the Invention:
[0084] Prodrugs are derivatives of the compounds of the invention which have metabolically
cleavable groups and become by solvolysis or under physiological conditions the compounds
of the invention which are pharmaceutically active
in vivo. For example, ester derivatives of compounds of this invention are often active in
vivo, but not in vitro. Other derivatives of the compounds of this invention have
activity in both their acid and acid derivative forms, but the acid derivative form
often offers advantages of solubility, tissue compatibility, or delayed release in
the mammalian organism (see, Bundgard, H., Design of Prodrugs, pp. 7-9, 21-24, Elsevier,
Amsterdam 1985). Prodrugs include acid derivatives well known to practitioners of
the art, such as, for example, esters prepared by reaction of the parent acid with
a suitable alcohol, or amides prepared by reaction of the parent acid compound with
an amine. Simple aliphatic or aromatic esters derived from acidic groups pendant on
the compounds of this invention are preferred prodrugs. In some cases it is desirable
to prepare double ester type prodrugs such as (acyloxy) alkyl esters or ((alkoxycarbonyl)oxy)alkyl
esters.
[0085] Preferred are the C
1-C
8 alkyl, C
2-C
8 alkenyl, aryl, C
7-C
12 substituted aryl, and C
7-C
12 arylalkyl esters of the compounds of the invention (per formula I) Particularly preferred
are the C
1-C
4 alkyl esters, for example, where the R
3 acidic group has been esterified to form a group represented by one of the following
formulae:

and

[0086] Other specific prodrug derivatives which are compounds of the invention are represented
by the formulae (Xa) and (Xb) shown below:

[0087] Acylated basic radicals which are part of basic group on the compounds of the invention
have been found to significantly enhance bioavailability. Without being bound by any
theory of operation, it is believed that lowering the basicity of basic group (Q)
makes the compounds of this invention less subject to "food effect", that is, they
have good availability in therapeutic administration to an animal without fasting.
[0088] Compounds of this invention may beneficially be dual prodrug derivatives. For example,
the acidic group (R
3) may be reacted to form an ester and the basic group Q (or basic radical Q
1) may additionally be reacted to form an acylated basic derivative. Moreover, the
prodrug derivatives of the compounds of this invention may be combined with other
features herein taught to enhance bioavailability, for example, substitution of fluorine
atoms on the D ring of the compounds of formula (II). These combined features result
in a compound such as represented by the formula (Xc) :

[0089] Another highly preferred class of prodrugs of the invention are those formed by acylating
the basic radicals (e.g., Q
1) present on the compounds of the invention. The acyl portion of the acylated basic
radical has the general formula:

where R is C
1-C
8 alkyl, C
2-C
8 alkenyl, aryl, C
7-C
12 substituted aryl, and C
7-C
12 arylalkyl; and X is a bond, C, O, S, or N. Preferably R is C
1-C
4 alkyl and X is oxygen. For example, acylated basic radical prodrugs of the invention
are prepared and illustrated in A, B, C, and D below:
A) acylation of amidine results in a prodrug derivative group:

B) acylation of a cyclic amine such as piperidine results in a prodrug derivative
group:

C) acylation of guanidine results in a prodrug derivative group:

D) acylation of a primary amine results in a prodrug derivative group:

where, for A, B, C, and D above, R is as defined above for the acylated portion of
the basic group.
[0090] The therapeutic compounds of this invention include prodrug derivatives of bicyclic
compounds having a nucleus formed from two fused six membered rings, A and B, represented
by the formula (Xd):

wherein;
A1, A3, A4 are independently selected from carbon, oxygen, sulfur, and nitrogen;
A2 is independently selected from carbon or nitrogen, provided that A2 have an unsatisfied bond if A2 is N and provided that at least two of A1, A2, A3, and A4 are carbon;
B1, B2, B4 are independently selected from carbon, oxygen, sulfur, and nitrogen;
B3 is independently selected from carbon or nitrogen, provided that B3 have an unsatisfied bond if B3 is N and provided that at least two of B1, B2, B3, B4 are carbon;
n is a number from 2 to 6;
R0 is the same or different and is independently selected from hydrogen, alkyl, halosubstituted
alkyl, alkenyl, alkynyl, cycloalkyl, aryl, arylalkyl, hydroxy, alkoxy, aralkoxy, amino,
substituted amino, carbamoyl, carboxy, acyl, cyano, halo, nitro, sulfo, =O, or =S;
with the proviso that if R0 is =O or =S, then only one of B1, B2, B3, and B4 may be nitrogen;
m is a number from 2 to 6;
R10 is the same or different and is independently selected from hydrogen, alkyl, halosubstituted
alkyl, alkenyl, alkynyl, cycloalkyl, aryl, arylalkyl, hydroxy, alkoxy, aralkoxy, carboxy,
acyl, cyano, halo, nitro, sulfo, =O, and =S; with the proviso that only one R10 may be =O or =S;
linking group -(L)- is a bond or a divalent substituted or unsubstituted chain of
from 1 to 10 atoms selected from the group consisting of carbon, nitrogen, sulfur,
and oxygen; and;
Q2 is selected from (i) a basic group, or (ii) a basic group containing an acylated
basic radical;
R13 is selected from (i) an acidic group containing an acid radical, or (ii) an acidic
group containing an ester derivative of an acid radical;
provided that at Q2 is a basic group containing an acylated basic radical or R13 is an acidic group containing an ester derivative of an acid radical.
[0091] A preferred form of prodrug derivative is a compound of formula (Xd) having dual
prodrug functionality, that is, where Q
2 is a basic group containing an acylated basic radical and R
13 is an acidic group containing an ester derivative of an acid radical.
[0092] Another preferred form of prodrug is a compound of formula (Xd) wherein the acylated
portion of the acylated basic radical has the general formula:

where R is C
1-C
8 alkyl, C
2-C
8 alkenyl, aryl, C
7-C
12 substituted aryl, and C
7-C
12 arylalkyl; and X is a bond, C, O, S, or N. Preferably R is C
1-C
4 alkyl and X is oxygen.
[0093] The group Q
2 may comprise two parts, namely, (i) one or more radicals selected from basic radicals
or acylated basic radicals each designated, "Q
3", and (ii) a cyclic group D (as previously defined form formula Iw). zzz
[0094] A general formula for the prodrug derivatives of this invention is a bicyclic compound
having a nucleus formed from two fused six membered rings, A and B, represented by
the formula (Xe), or a pharmaceutically acceptable salt, solvate or prodrug derivative
thereof:

wherein;
A1, A3, A4 are independently selected from carbon, oxygen, sulfur, and nitrogen;
A2 is independently selected from carbon or nitrogen, provided that A2 have an unsatisfied bond if A2 is N and provided that at least two of A1, A2, A3, and A4 are carbon;
B1, B2, B4 are independently selected from carbon, oxygen, sulfur, and nitrogen;
B3 is independently selected from carbon or nitrogen, provided that B3 have an unsatisfied bond if B3 is N and provided that at least two of B1, B2, B3, B4 are carbon;
n is a number from 0 to 6;
R0 is the same or different and is independently selected from hydrogen, alkyl, halosubstituted
alkyl, alkenyl, alkynyl, cycloalkyl, aryl, arylalkyl, hydroxy, alkoxy, aralkoxy, amino,
substituted amino, carbamoyl, carboxy, acyl, cyano, halo, nitro, sulfo, =O, or =S;
with the proviso that if R0 is =O or =S, then only one of B1, B2, B3, and B4 may be nitrogen;
m is a number from 0 to 6;
R10 is the same or different and is independently selected from hydrogen, alkyl, halosubstituted
alkyl, alkenyl, alkynyl, cycloalkyl, aryl, arylalkyl, hydroxy, alkoxy, aralkoxy, carboxy,
acyl, cyano, halo, nitro, sulfo, =O, and =S; with the proviso that only one R10 may be =O or =S;
t is a number from 0 to 3;
R20 is the same or different and is independently selected from hydrogen, halogen, alkyl,
halosubstituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl, arylalkyl, hydroxy, alkoxy,
aralkoxy, carboxy, acyl, cyano, halo, nitro, sulfo;
linking group -(L)- is a bond or a divalent substituted or unsubstituted chain of
from 1 to 10 atoms selected from the group consisting of carbon, nitrogen, sulfur,
and oxygen; and;
D is a ring formed from 5 to 8 ring atoms and said ring atoms are independently selected
from carbon, nitrogen, oxygen, or sulfur, with the proviso that at least two D ring
atoms are carbon;
w is an integer from 1 to 3;
Q3 is selected from (i) a basic radical, or (ii) an acylated basic radical;
R13 is selected from (i) an acidic group containing an acid radical, or (ii) an acidic
group containing an ester derivative of an acid radical;
provided that Q3 is an acylated basic radical or R13 is an acidic group containing an ester derivative of an acid radical;
[0095] The integer w is preferably 1.
[0096] It is preferred in formula (Xe) that R
20 be chlorine and/or fluorine and t equal 1 or 2. Also preferred are compounds of formula
(Xe) wherein Q
3 is an acylated basic radical and R
13 is an acidic group containing an ester derivative of an acid radical.
[0097] The most preferred acylated basic groups are carbamic acid esters of amidine, piperidine,
or guanidine basic radicals. Carbamate acid C
1 to C
4 alkyl esters of amidine radicals are most highly preferred.
[0098] Carbamate ester prodrug derivatives of the invention may be prepared by a method
such as shown in Scheme 27.
[0099] Preferred prodrug derivatives of the compounds of the invention having various features
discused in this section are represented by the formulae (Xf) to (Xr) below:

where, R = -H, -OMe, -OEt, -OPr, C1-C4 alkyl; R15 = Me, Et, Pr; and

where,
R = -H, -OMe, -OEt, -OPr,
X = -Cl, -F, -H,
R15 = Me, Et, Pr.
Method of Making Compounds of the Invention
[0100] General synthesis schemes 1 through 33, infra., are used to prepare the compounds
of the invention.
[0101] The following abbreviations are used throughout the synthesis Schemes and Examples:
- TBAF
- tetra-butyl ammonium fluoride
- Tf
- (triflate) - trifluoromethane sulfonate
- Boc
- tertiary-butoxy carbonyl
- Bn
- benzyl
- But
- tertiary butyl
- DMF
- dimethyl formamide
- TFA
- trifluoroacetic acid
- Cbz
- benzyloxycarbonyl
- EDCI
- 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide
- DMAP
- dimethylaminopyridine
- LHMDS
- lithium hexamethyl disilazane
- THF
- tetrahydrofuran
- DIBAH
- diisobutyl aluminum hydride
- Boc2O
- di-tert-butyl dicarbonate
- HMDS
- hexamethyl disilazane
- TSOH
- p-toluene sulfonic acid
- MCPBA
- meca-chloro-peroxy benzoic acid
- NMO
- 4-methylmorpholine-N-oxide
- TFAA
- Trifluoroacetic anhydride
- TBSCL
- tert-butyl dimethyl silyl chloride
- TMEDA
- N,N,N',N'-tetramethylethylenediamine
- LDA
- lithium diisopropylamide
General Comments :
[0102] The reactions described in the reaction schemes are carried out using standard chemical
methodologies described and referenced in standard textbooks. Starting materials are
commercially available reagents and reactions are carried out in standard laboratory
glassware under reaction conditions of standard temperature and pressure, except where
otherwise indicated.

[0103] Scheme 1 teaches a method of preparing 2,6-disubstituted isoquinolones having an
ether linked arginine isostere at C
6 and an acetic acid residue at position 2. In the first step of Scheme 1, isoquinolone
(1) reacts with benzyl bromide in the presence of potassium carbonate in refluxing
acetone to give a benzyl protected phenol (2). This compound reacts with sodium hydride
and is then alkylated on nitrogen with either alpha-bromo tert-butyl acetate or alpha-bromo
methyl acetate to give a 2-substituted isoquinolone (3a) (6-benzyloxy-3,4-dihydro-1-oxo-2(1H)isoquinolone
acetic acid -1,- dimethylethyl ester) or (3b). The C
6 benzyl group is subsequently removed with hydrogen and palladium and subsequent alkylation
of the 6-hydroxy group is accomplished with K
2CO
3 and alkyl bromide to give the di-substituted isoquinolone (5). Compound (5) is then
transformed into the Boc protected amidine (6) using a series of reactions, namely;
(i) reacting the nitrile with H
2S, (ii) alkylating the intermediate thioamide with methyl iodide, (iii) reacting the
intermediate thioimidate with ammonium acetate, and (iv) thereafter Boc protecting
the formed amidine to give compound (6). Compound (6) is deprotected with neat TFA
giving (7) as the TFA salt.

[0104] Scheme 2 describes a synthesis method suitable to give carbon substitution at position
C
6 of the bicyclic nucleus. In this scheme compound (4) (6-hydroxy-3,4-dihydro-1-oxo-2(1H)
isoquinolone acetic acid -1,1- dimethylethyl ester) from Scheme 1 is transformed into
the triflate (8) using triflic anhydride and pyridine. The compound is thereafter
reacted with the acetylenic compound (9a) or (9b) in the presence of palladium to
give acetylene linked benzonitrile (10a) or (10b). Compound (10a) or (10b) is transformed
again with the same set of procedures used to transform compound (5) (6-[(4 cyanophenyl)
methoxy]-3,4-dihydro-1-oxo-2(1H) isoquinolone acetic acid, -1,1-dimethyl ethyl ester)
to compound (6) (6-[[4-(1,1 dimethyl ethoxy carbonyl aminoiminomethyl)phenyl] methoxy]-3,4-dihydro-1-oxo-2(1H)isoquinolone
acetic acid -1,1-dimethyl ethyl ester) to yield the amidine product (11a) or (11b).
Compounds (11a) or (11b) may also be deprotected again with TFA to give compound (12a)
or (12b). Alternatively, intermediate (10a) or (10b) can be either partially or fully
hydrogenated as shown in the scheme giving the alkylene or alkenylene linked compound
(13a) or (13b). Compound (13a) or (13b) is again transformed using the nitrile to
amidine conversion previously described (Scheme 1, steps 5>6), giving compound (14a)
or (14b) which is subsequently deprotected with TFA to give compound (15a) or (15b).

[0105] Scheme 3 describes the preparation of isoquinolones containing nitrogen substitution
at C
6. This scheme starts with triflate (8) whose preparation was previously described
in Scheme 2. The triflate is transformed to aryl ester (16) via the use of palladium,
carbon monoxide and methanol. The ester (16) is then saponified with lithium hydroxide
in aqueous THF. The free acid (7) is then subjected to a Curtius rearrangement (viz.,
formation of an isocyanate by thermal decomposition of acyl azides). The required
acyl azide is formed with a triphenyl phosphoryl azide and then pyrolized
in situ to give an isocyanate which is then trapped with benzyl alcohol giving Cbz protected
aniline (18).
CBz-Aniline (18) is then transformed into free amine (19) with catalytic hydrogenation.
Amine (19) is then acylated with paracyanobenzoic acid in the presence of EDCI and
DMAP giving the amide-linked compound (20). Compound (20) is then transformed into
the Boc protected amidine (21) again using the conditions of Scheme 1 and that compound
is then deprotected with TFA to give compound (22).

[0106] Scheme 4 describes how to make 2,6-disubstituted isoquinilones in which the 2-position
is substituted with an aspartic acid moiety. Scheme 4 starts with compound (3b) whose
preparation is described in Scheme 1. Compound (3b) is deprotonated with LHMDS and
the resulting anion is quenched with alpha-bromo-
t-butyl acetate to give compound (23). The 6-benzyl group of compound (23) is removed
with palladium and hydrogen to give the free phenol (24). Compound (24) is then alkylated
as described for the preparation of compound (5) in Scheme 1. The methyl ester (25)
is then saponified with lithium hydroxide in THF to give the free carboxylate (26).
The free carboxylate is then coupled with a variety of amines in the presence of EDCI
and DMAP to give the half amide esters (27a) thru (27e). The half amide esters (27a)
thru (27e) are then transformed again using the same protocol as previously described
in Scheme 1 (steps 5-6)to give the Boc protected amidines (28a) thru (28e). The Boc
protected amidine is then deprotected with TFA to give compounds (29a) thru (29e).

[0107] Scheme 5 describes the preparation of 2,6-disubstituted isoquinilones in which the
2-position is substituted by an aspartate isostere. Scheme 5 compounds differ from
the compounds prepared in Scheme 4 in that the R group of the Scheme 5 compound (36)
does not contain an amide linkage like the Scheme 4 compounds (29a) thru (29e). Compound
(2), the starting material, is prepared by the method of Scheme 1, then acylated with
a variety of activated acids (acid halides or anhydrides) to give the corresponding
imides (30a) thru (30e). Thereafter the imide is selectively reduced at its exocyclic
carbonyl with DIBAH and then entrapped with acidic methanol to give alpha-methoxy
amides (31a) thru (31e). Alternatively, alpha-methoxy amides (31) can be prepared
by reacting the sodium salt of (2) with an appropriate alpha chloro ether (37). All
of the alpha-methoxy amides (31a) thru (31g) are reacted with boron trifluoride etherate
in the presence of a ketene acetal to give the beta,beta-di-substituted propionates
(32a) through (32g). Thereafter, the benzyl group is removed from the 6 position by
catalytic hydrogenation and phenols can be alkylated again in the same manner as shown
in Scheme 1 (steps 4>5) to give the ether linked nitriles (34a) to (34g). That nitrile
can then be converted to the Boc protected amidine (35a) to (35g) as shown in Scheme
1 (steps 5>6), Thereafter, deprotection gives the final compounds (36a) to (36g).

[0108] Scheme 6 describes the preparation of compounds of the invention having a tetralin
nucleus. 6-methoxy-2-tetralone (38) is reacted with tert-butyl diethylphosphono acetate
to give unsaturated ester (39). Subsequent hydrogenation removes the unsaturation
to give compound (40). Compound (40) is treated with boron tribromide and the crude
product is reesterified with HCl and ethanol to give (41). The phenol (41) is then
alkylated in the same manner as shown in Scheme 1 (step 4-5) giving (42). The nitrile
can then be converted to the Boc protected amidine (43) as shown in Scheme 1 (step
5-6). The amidino ester (43) is then saponified with sodium hydroxide to give compound
(44), which then is later deprotected with TFA and anisole to give the final product
(45).

[0109] Scheme 7 describes the preparation of compounds of the invention having a guanidine
group as the basic functionality. Phenol (4), prepared in scheme 1, is alkylated with
bromide (51) (prepared from the dibromide and potassium pthalimide) giving adduct
(46). This compound is deprotected with aqueous hydrazine giving amine (47). Compound
(47) is transformed into protected guanidine (49) with N,N'-bis(tert-butoxy carbonyl)-S-methyl-isothiourea.
[0110] Compound (49) is deprotected with TFA giving product (50) as the trifluoroacetate
salt.

[0111] Scheme 8 describes the preparation of compounds of the invention having an amine
group as the basic functionality.
[0112] Compound (33a), prepared in scheme 5, is coupled with alcohol (51) (prepared from
3-(4-pyridyl)-propanol using standard protocols) using triphenyl phosphene and diethyl
azodicarboxylate giving compound (52). Compound (52) is deprotected with neat TFA
giving product (53) as the TFA salt.

[0113] Scheme 9 describes the preparation of 2-6 disubstituted tetralins in which the 2
position is occupied by an a-alkoxyacetic acid residue and the 6 position retains
either an ether linked benzamidine or an ether linked 4-alkylpiperidine moiety. The
scheme begins with 6-methoxy-2-tetralone (60) which is sequentially treated with NaBH
4 and then with DIBAH giving dihydoxy compound 62. The phenolic hydroxyl can be selectively
alkylated with either α-bromo-p-tolunitrile or the appropriate 4-alkylpiperidine giving
compounds 63 and 67 respectively. Both compounds are then alkylated with tert-butyl
bromoacetate under phase transfer conditions providing 64 and 68. Nitrile 64 is converted
to the Boc protected amidine 65 and then to product 66 using the same sequence of
reactions described in Scheme 1. Compound 68 is converted to the fully deprotected
69 by treatment with TFA.

[0114] Scheme 10 outlines the preparation of 2,6-disubstituted tetralins in which an α-aminoacetic
acid moiety resides at position 2 and an ether linked 4-alkylpiperidiene emanates
from position 6. Alcohol 67, prepared in Scheme 9, is oxidized with DMSO and TFAA
using the conditions of Swern giving ketone 70 which is reductively aminated with
glycine tert-butyl ester giving 71. This material is then deprotected with TFA giving
72.

[0115] Scheme 11 outlines the preparation of 2,6-disubstituted tetralins in which the 2
position retains an α-aminoacetic acid residue and the 6 position is occupied by an
ether linked benzamidine. The synthesis starts with alcohol 63 (Scheme 9) which is
oxidized with TFAA and DMSO (method of Swern) giving ketone 73. This material is then
reductively aminated with glycine tert-butyl ester giving 74. The secondary nitrogen
is then either Boc protected (76) or acylated (75). The Boc derivative is then transformed
into protected amidine 77 using the same sequence of reactions outlined in Scheme
1. The material is then fully deprotected with TFA giving 78. In a like manner, the
acetyl derivative 75 is transformed into 80.

[0116] Scheme 12 outlines the preparation of tetralins having an acetic acid residue at
C
2 and an amide linked benzamidine at C
6. In the first step, tetralone 81 is reduced with NaBH
4 and the resultant unstable alcohol is dehydrated with TsOH in benzene giving dihydronapchalene
82. Osymylation of 82 affords diol 83 which is then subjected to the action of TsOH
in refluxing benzene. The unstable 2-tetralone thus formed is not isolated but rather
allowed to react with the sodium salt of tert-butyl diethylphosphonoacetate giving
unsaturated ester 84 as a mixture of olefin isomers. This material is subjected to
hydrogenation over palladium which effects saturation of the olefin and removal of
the CBz group providing aniline 85.
[0117] Acylation of 85 with 4-cyanobenzoic acid is accomplished with the aid of EDCI and
the resulting amide 86 is transformed into the Boc protected amidine 87 using conditions
previously described in Scheme 1. Removal of the Boc moiety and cleavage of the tert-butyl
ester is accomplished with TFA giving 88.

[0118] Scheme 13 describes the preparation of tetralin derivatives in which position 2 is
substituted with an a-alkoxyacetic acid moiety and position 6 is substituted by an
amide linked benzamidine. In this scheme, compound 82 from Scheme 12 is allowed to
react with NaH and benzylbromide giving tertiary carbamate 88. This material is then
subjected to oshylation and dehydration in the same manner as described for compound
83 in Scheme 12. The formed unstable 2-tetralone is immediately reduced to alcohol
90 with NaBH
4. This material is alkylated with tert-butyl bromoacetate under phase transfer conditions
resulting in ether 91. Catalytic hydrogenation liberates the 6-amino moiety (92) which
is acylated with 4-cyanobenzoic acid in the presence of EDCI giving 93. Nitrite 93
is transformed into Boc protected amidine 94 using the series of transformations described
in Scheme 1. Simultaneous deprotection of the amidine and acid moieties is accomplished
with TFA giving final product 95,

[0119] Scheme 14 outlines the synthesis of tetralones bearing an acetic acid moiety at position
2 and either an amide linked benzamidine or amide linked 4-alkylpiperidine at position
6. The scheme starts with tetralone 96 which is allowed to react with glyoxylic acid
in the presence of NaOH yielding condensation product 97. The unsaturated ester 97
is reduced with Zn in HOAc and the resulting compound is transformed into aniline
98 by first removing the acetate with 6N HCl and then esterifying the acid moiety
with ethanolic HCl. This material is then acylated with 4-cyanobenzoic acid via the
agency of EDCI giving 99. The nitrile moiety of 99 is converted to Boc protected amidine
100 using the series of reactions described in Scheme 1. Saponification of the ester
moiety with NaOH followed by treatment with TFA gives 102.
[0120] Compounds containing an amide linked 4-alkylpiperdine can be prepared by acylating
aniline 98 with 103 giving analog 104. Saponification of ester 104 followed by TFA
deprotection of the piperidine gives 106.

[0121] Scheme 15 teaches a method of preparing tetralone derivatives in which position 2
is occupied by an unsaturated acid and position 6 is substituted by either an amide
linked benzamidine or a 4-akylpiperidine. In the first step, compound 97 (scheme 14)
can be converted to aniline 107 by removing the acetate with 6N HCl and subsequent
esterification with ethanolic HCl. This material can then be acylated with either
4-cyanobenzoic acid or the appropriate 4-alkylpiperidine (103). In the former case,
the nitrile 111 can be transformed into amidine 112 using the same sequence of reactions
described in Scheme 1. Saponification of 112 followed by treatment with TFA should
yield 114. Piperidine adduct 108 can be subjected to saponification and TFA deprotection
providing 110 in a similar manner.

Scheme 16 describes the preparation of dihydronapthalene derivatives containing an
acetic acid moiety at position 2 and an amide linked benzamidine at position 6. Tetralone
100 (Scheme 14) is allowed to react with NaBH
4 in ethanol giving unstable alcohol 115. This material is treated with TsOH in THF
giving dehydrated product 116. Ester saponification followed by deblocking the amidine
with TFA gives the desired product 118.

[0122] Scheme 17 outlines the general preparation of 2,6-disubstituted tetralones in which
the 2 position is substituted with an acetic acid residue and the 6 position contains
an amide-linked halogen-substituted benzamidine. Aniline 98 (prepared in Scheme 14)
is allowed to react with benzoic acid 119 (prepared from 4-amino-2-fluoro-toluene
using standard methods) in the presence of EDCI and DMAP. The resulting amide (120)
is transformed into Boc protected amidine 121 using the same procedures outlined in
Scheme 1. The ester moiety is then hydrolyzed giving acid 122 and then treatment with
TFA provides compound 123.

[0123] Scheme 18 teaches a method of preparing 2,6-disubstituted napthalenes having an acetic
acid residue at position 2 and an ether linked arginine isostere at position 6. In
the first step of Scheme 18, bromonapthalene 124 is subjected to transmetalation with
t-BuLi and the resulting anion is quenched with ethyl oxalate. The resulting adduct
125 is then reduced with NaBH
4 and the formed alcohol is acylated with acetic anhydride. Catalytic hydrogenation
removes the benzilic acetate and liberates the 6-hydroxy moiety giving compound 126.
The free phenol is then alkylated with α-bromo-p-tolunitrile in the presence of K
2CO
3 giving disubstituted naphthalene 127. The nitrile moiety is then transformed into
the Boc protected amidine 128 using the same sequence of reactions previously described
in Scheme 1.
[0124] Saponification of the ester in 128 followed by removal of the Boc group with TFA
gives final compound 130.

[0125] Scheme 19 describes the preparation of disubstituted tetrahydroisoquinoline derivatives
bearing an acetic acid moiety at position 2 and either an ether linked benzamidine
or 4-alkyl piperidine moiety at position 6. The initial isoquinoline nucleus is prepared
by LiAlH
4 reduction of benzyl protected isoquinolone 2 (Scheme 1). This material was processed
by either Boc protection giving compound 131 or alkylated with tert-butyl bromoacetate
resulting in the formation of 132. The Boc protected material was subjected to hydrogenation
which liberated the C
6 phenol which was then alkylated with α-bromotolunitrile giving adduct 137. The Boc
group of this compound was cleaved with TFA and the resulting amine was then alkylated
with tert-butyl bromoacetate giving compound 138. This compound was transformed into
the Boc protected amidine 139 and then to the deprotected variant 140 using the procedures
outlined in Scheme 1. The
N-alkylated compound 132 was similarly subjected to hydrogenation and the resulting
phenol was alkylated with the appropriate 4-alkylpiperidine giving 134. This material
was deprotected with TFA giving 135.

[0126] Scheme 20 teaches how to prepare 2,6-disubstituted tetrahydroisoquinoline derivatives
bearing an acetic acid residue at position 2 and an amide linked benzamidine at position
6. The synthesis begins with acidic hydrolysis of the 6-acetamido group of isoquinolone
141 giving aniline 142. The crude material is then subjected to the action of benzyl
bromide and K
2CO
3 in CH
3CN giving a mixture of mono and di-benzyl protected isoquinolones. This mixture is
subjected to LiAlH
4 reduction forming the tetrahydroisoquinoline which is immediately treated with di-tert-butyl
dicarbonate. The formed Boc protected material is then hydrogenated over palladium
providing aniline 143. This material is acylated with p-cyanobenzoic acid giving 144.
Treatment of this material with TFA gives the secondary amine which is alkylated with
tert-butyl bromoacetate providing 145. Conversion of 145 to the Boc protected amidine
146 and then to its deprotected congener 147 is accomplished using the same procedures
as outlined in Scheme 1.

[0127] Scheme 21 describes a synthesis method suitable for the formation of 2,6-disubstituted
tetralins containing a propionate or propenoate moiety at position 2 and an amide
linked benzamidine at position 6. In the first step, nitro ester 148 is reduced with
LiBH
4 and the resultant alcohol is protected as its TBS ether. Compound 149 is then subjected
to hydrogenation and the formed aniline is immediately treated with EDCI and p-cyanobenzoic
acid giving amide 150. The silyl group of 150 is removed and the derived alcohol is
subjected to oxidation with DMSO and oxalyl chloride (method of Swern). The aldehyde
thus formed is not purified, rather it is allowed to react with the sodium salt of
t-butyl diethylphosphonoacetate which yields a separable mixture of 151(cis) and 152
(trans) olefin isomers. The trans isomer 152 is converted to the Boc protected amidine
and then to deprotected compound 155 using the sequence described in Scheme 1. The
cis isomer is subjected to hydrogenation over palladium to give saturated analog 153.
This material is also converted to the Boc protected amidine and then to its deprotected
congener 154 as described in Scheme 1.

[0128] Scheme 22 describes a synthesis method for disubstituted tetralins bearing an α-alkoxyacetic
acid residue at C
2 and a C
6 carboxyl linked benzamidine. This scheme begins with 6-bromo-2-tetralone (156) which
is reduced with NaBH
4 and the resultant alcohol protected as its tert-butyldimethylsilyl (TBS) ether giving
157. Treatment of this compound with t-BuLi effects halogen metal exchange and the
formed anion is quenched with CO
2. The resulting carboxylate is immediately transformed into the benzyl ester with
benzyl alcohol and EDCI. The TBS group is removed during workup with TBAF affording
alcohol 158. The free secondary hydroxyl is alkylated with tert-butyl bromoacetate
using phase transfer conditions and the 6-carboxylate is liberated via catalytic hydrogenation
affording 159. Amide 160 is the result of allowing 159 to react with 4-cyanoaniline
in the presence of EDCI and DMAP. Nitrile 160 is converted to the BOC protected amidine
and thereafter to the fully deprotected 161 using conditions outlined in Scheme 1.

[0129] Scheme 23 outlines the preparation of tetralins having an acetic acid residue at
C
2 and a C
6 carboxyl linked benzamidine. In the first step, bromotetralone 156 is treated with
ethylene glycol and TsOH under dehydrating conditions giving ketal 162. This material
is treated with tBuLi and the resulting anion is quenched with CO
2. The formed acid is immediately esterified with benzyl alcohol and EDCI giving 163.
The spiro ketal contained in 163 is cleaved with aqueous HCl in acetone and the formed
ketone is allowed to react with the sodium salt of tert butyl diethylphosphonoacetate
giving 164 as a mixture of olefin isomers. Catalytic hydrogenation over Pd removes
the unsaturation and liberates the C
6 carboxylate giving acid 165. Condensation of this compound with 4-aminobenzonitrile
gives amide 166. Conversion of 166 to Boc protected amidine 167 and then to final
compound 168 is accomplished using the same sequence outlined in Scheme 1.

[0130] Scheme 24 describes the preparation of 3,7-disubstituted benzopyrans in which the
3-position is substituted with an α-alkoxyacetic acid moiety and the 7 position is
substituted with an amide linked benzamidine. The synthesis begins with the allyl
substituted aromatic 169. Acetamide hydrolysis is effected with NaOH in EtOH (Claisens
alkali) and the resulting aniline is re-protected as its CBz counterpart. The free
phenol is then acylated with acetic anhydride giving 170. The olefin is reacted with
MCPBA giving the corresponding epoxide which is rearranged in the presence of NaI
giving a mixture of 3-hydroxy and 3-acetoxy benzopyrans. This mixture is treated with
LiOH giving alcohol 171. The alcohol moiety of 171 is then converted to its TBS ether
and the resulting compound is alkylated on nitrogen to give fully protected 172. Liberation
of the C
3 hydroxy with TBAF followed by alkylation with tert-butyl bromoacetate under phase
transfer condition gives 173. Catalytic hydrogenation provides aniline 174 which is
acylated with 4-cyanobenzoic acid, providing amide 175. This material is first converted
to the corresponding protected benzamidine 176 and then to its deblocked congener
177 using the same sequence of events outlined in Scheme 1.

[0131] Scheme 25 outlines the preparation of 2,6-disubstituted tetralones in which the 2
position is substituted by an acetic acid moiety and the 6 position is substituted
by either an alkoxy-linked benzamidine or alkoxy-linked 4-alkylpiperidine. In the
first step, tetralone 178 is treated with NaOH and glyoxylic acid giving adduct 179.
This material is reduced with Zn in acetic acid and the resulting acid (180) is reacted
with diphenyldiazomethane giving benzhydryl ester 181. The free phenol can then be
alkylated with α-bromo-p-tolunitrile to give 184 or with the appropriate 4-alkylpiperdine
giving 182. Nitrile 184 is then converted to the corresponding Boc protected amidine
185 and then to the fully deprotected compound 186 using the same sequence of reaction
outlined in Scheme 1. Compound 182 is deprotected with TFA giving compound 183.

[0132] Scheme 26 teaches a method to prepare tetrahydroisoquinolins in which the 2-position
is substituted by an oxamic acid residue and the 6-position contains an ether linked
benzamidine. In the first step, isoquinolone 2 is treated with LiAlH
4 and the resulting product of reduction is acylated with methyl oxalylchloride giving
compound 187. This material is subjected to hydrogenation and the resulting phenol
is alkylated with either α-bromotolunitrile or the appropriate 4-alkylpiperidine giving
compounds 191 and 189 respectively. The nitrile moiety of 191 is transformed into
Boc protected amidine 192 using the same procedures described in scheme 1. This material
is then saponified with NaOH and the resulting acid is treated with TFA giving 193.
Compound 190 is prepared using a similar saponification deprotection sequence.

[0133] Scheme 27 describes the acylation of the amidine moiety contained in 2,6-disubstituted
tetralones 365 and 366 which are prepared from compounds 102 and 123 (Scheme 14 and
17 respectively) by esterification with ethanol. The acylation is accomplished by
reacting the benzamidine containing compound with an alkyl chloroformate in the presence
of aqueous base, thus forming the derivatives 367 to 370. These materials can then
be subjected to saponification with ethanolic NaOH yielding the free acid (see 371
in Scheme 27).

[0134] The procedure of Scheme 27 is general and has also been applied to compounds containing
an isoquinolone nucleus as shown in Scheme 28. In a like manner, one can also prepare
N-acylated derivatives of benzamidine containing tetrahydroisoquinolins or benzopyrans.

[0135] Scheme 29 describes the preparation of 2,6-disubstituted tetralones in which the
2-position is occupied by an acetic acid residue and the 6-position maintains an amide
linked 4-propenoyl piperidine moiety. In the first step, alcohol 384 (prepared form
4-pyridylcarbinol by hydrogenation and protection) is oxidized with oxalyl chloride
and DMSO giving the corresponding aldehyde. This material is not characterized but
rather, reacted crude with the sodium salt of triethyl phosphonoacetate which gives
the desired unsaturated ester 385. This material is saponified with LiOH and the resulting
acid 386 is activated with oxalyl chloride giving 387. Aniline 98 reacts with acid
chloride 387 giving adduct 388. This compound is N-deprotected with TFA giving ester
389 after salt exchange with HCl. Alternatively, saponification with LiOH first gives
the free acid 390 which can then be N-deprotected with TEA providing 391.

[0136] Scheme 30 teaches the preparation of 2,6 disubstituted tetrahydroisoquinolines bearing
an acetic acid residue at position 2 and an amide linked 4-propenoyl piperidine at
position 6. In the first step, the 6-amino moiety of 133 is acylated with acid chloride
387 (Scheme 29) giving adduct 392. This material can be fully deprotected with TFA
providing 393.

[0137] Scheme 31 outlines the preparation of 2,6-disubstituted tetralones in which the 2
position is occupied by an acetic acid moiety and the 6 position supports an amide-linked
difluoro benzamidine. In the first step, difluoro benzonitrile 394 is lithiated with
n-butyl lithium and the resulting anion is quenched with CO
2 giving acid 395. This compound is then treated with oxalyl chloride and the resulting
acid chloride 396 is reacted with aniline 98 giving adduct 397. The nitrile moiety
in 397 is transformed into Boc protected amidine 398 using the same sequence of reactions
employed for conversion of 5 to 6 as described in Scheme 1. Compound 398 can be deprotected
with TFA providing 399. Alternatively, 398 can be fully deprotected by first cleaving
the ester moiety with NaOH and then deprotecting the amidine with TFA yielding 400.

[0138] Scheme 32 describes the preparation of 2,6-disubstituted tetralones bearing an acetic
acid moiety at position 2 and an amide-linked amidino pyridine at position 6. In the
first step, pyridine 401 is reacted with Et
3N, TMSCl, and NaCN giving acid 402. This material is coupled with aniline 98 giving
adduct 403. The nitrile in 403 is then reacted with the sodium salt of methane thiol
giving the methylthioimidate. This intermediate is reacted with ammonium iodide providing
an amidine which is BOC protected giving 404. Compound 404 is first reacted with ethanolic
NaOH to cleave the ester and then with TFA to deprotect the amidine providing the
fully deprotected congener 405.

[0139] Scheme 33 describes the preparation of 2,6-disubstituted tetralones in which the
amide-linked amidine contains a thiophene nucleus. In the first step, thiophene 406
is metalated with LDA and the resulting anion is quenched with CO
2 giving acid 407. This acid is reacted with compound 98 in the presence of EDCI giving
amide 408. The nitrile moiety in 408 is converted to a Boc protected amidine 409 using
the same sequence of reactions used for the formation of compound 6 in Scheme 1. The
resulting compound is first saponified with ethanolic NaOH and then N-deprotected
with TFA giving compound 410 as the TFA salt.

[0140] Scheme 34 teaches the preparation of 2,6 disubstituted benzopyrans in which the 2
position retains an acetic acid moiety and the 6 position contains an amide-linked
fluoro-substituted benzamidine. In the first transformation, the nitro group is reduced
with ammonium formate and palladium and the resulting aniline is Boc protected. The
B ring unsaturation is then removed with Pd/C giving lactone 202. This material is
reduced with DIBAH giving an intermediate lactol which is reacted with ethoxycarbonylmethylene
triphenylphosphorane giving benzopyran 204. This material is then N-deprotected with
TFA and the resulting aniline reacted with the acid chloride derived from fluoro-acid
119 giving adduct 307. This material was then subjected to the action of HCl in ethanol
giving the intermediate imino-ether which was not characterized but instead reacted
with ammonia resulting in the formation of 304. This material was then hydrolyzed
with NaOH in ethanol giving the desired free acid 308 after neutralization.
Examples
[0141] The following examples are provided to enable one skilled in the art to practice
the present invention. These examples, however, are not to be read as limiting the
scope of the invention as it is defined by the appended claims.
[0142] The reference numbers used in the following Examples refer to the corresponding compound
shown in the preceding reaction Schemes 1 through 26:
Example 1
[0143] Preparation of Ethyl rac-(6-(4-(Aminoiminomethyl)phenylmethoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (194):

Step A: Preparation of ethyl rac-(6-(4-cyanophenyl)methoxy-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (195)
[0144]

[0145] 6.0 g (25.4 mmol) ethyl rac-(3,4-dihydro-6-hydroxy-2H-1-benzopyran-2-yl)acetate (prepared
according to Eur. Pat. Appl. EP 129 906, the disclosure of which is incorporated herein
by reference) and 4.9 g (25.0 mmol) 4-cyanobenzyl bromide were dissolved 36 ml in
dry acetone, and 3.5 g (25.3 mmol) potassium carbonate were added. After stirring
overnight at 50 °C another 0.3 g (1.3 mmol) of the benzopyran were added, and the
reaction was continued for the same time. The inorganic solid was removed by filtration,
the filtrate concentrated in vacuo, and the pure nitrite obtained from the residue
by chromatography on silica gel with hexane/acetone 40:5.
Yield: 6.7 g (76 %) of pale yellow solid, m.p. 75-76 °C
Step B: Preparation of ethyl rac-(3,4-dihydro-6-(4-(ethoxycarbonimidoyl)phenylmethoxy)-2H-1-benzopyran-2-yl)acetate
hydrochloride, an intermediate represented by the formula (196):
[0146]

7.45 g (21.2 mmol) of the nitrile from Step (A) were suspended in 340 ml dry ethanol.
The suspension was cooled with an ice bath and saturated with gaseous hydrogen chloride
(approximately 5 hours). After standing overnight a clear solution had been formed.
The solution was evaporated to dryness in vacuo, and the compound (196) was stirred
with hexane, filtered with suction, and dried in vacuo.
Yield: 6.43 g (70 %) of a pale yellow powder,
m.p. 118-119 °C
Step C: Preparation of compound (194), ethyl rac-(6-(4-(aminoiminomethyl)phenylmethoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
hydrochloride:
[0147] 385 ml of a saturated solution of ammonia in ethanol were cooled with ice, and 6.43
g (14.8 mmol) of the intermediate from Step B were added. The Step B intermediate
was stirred overnight at room temperature, and the solvent was removed in vacuo. The
remaining solid title compound was stirred with hexane, filtered with suction, and
dried in vacuo at 40 °C.
Yield: 5.32 g (89 %) of white powder, m.p. 123-125 °C
Example 2
Preparation of rac-(6-(4-(Aminoiminomethyl)phenylmethoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
acid trifluoroacetate, a compound represented by the formula (197)
[0148]

Step A: Preparation of ethyl rac-(6-(4-(N-tert.-butoxycarbonyl(aminoiminomethyl))phenylmethoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (198):
[0149]

3.7 g (9.1 mmol) of the amidine of Example 1 was dissolved in 55 ml of a mixture
of THF / H
2O 1:1. After addition of 1.65 g (11.9 mmol) potassium carbonate, 1.99 g (9.1 mmol)
Boc
2O was added dropwise, and the mixture was stirred overnight at room temperature. The
mixture was then diluted with 100 ml ethyl acetate. The organic layer was separated,
washed with water, dried over sodium sulfate, and concentrated in vacuo to give the
pure protected amidine.
Yield: 4.3 g (100 %) of an oil.
Step B: Preparation of rac-(6-(4-(N-tert.-butoxycarbonyl(aminoiminomethyl))phenylmethoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
acid, an intermediate represented by the formula (199):
[0150]

5.2 g (11.1 mmol) of the ester from Step A was dissolved in 75 ml of ethanol. After
addition of 36 ml 2N aqueous sodium hydroxide the mixture was heated at 60 °C for
some minutes. The mixture was then adjusted to pH 6 with acetic acid. The ethanol
was removed in vacuo, and ethyl acetate was added. The organic layer was separated,
dried over sodium sulfate, concentrated in vacuo, and the title carboxylic acid was
obtained from the residue by chromatography on silica gel with dichloromethane / ethanol
40:5.
Yield: 2.0 g (41 %) of a white powder, m.p. 220-222 °C (dec.)
Step C: Preparation of rac-(6-(4-(aminoiminomethyl)phenylmethoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
acid trifluoroacetate
[0151] 0.15 g (0.34 mmol) of the protected amidine from Step B and 2.8 ml trifluoroacetic
acid were mixed and stirred at room temperature for 1.5 hours. The solvent was removed
in vacuo, and the title amidine precipitated after addition of 10 ml water. The product
was filtered with suction, stirred again with 10 ml water, filtered, and dried in
vacuo.
Yield: 0.09 g (58 %) of a white powder, m.p. 210-212°C
Example 3
Preparation of Ethyl rac-(6-(N-(4-(Aminoiminomethyl)benzoyl)amino)-3,4-dihydro-2H-l-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (200):
[0152]

Step A: Preparation of tert.-butyl (2-oxo-2H-1-benzopyran-6-yl)carbamate, an intermediate
represented by the formula (201):
[0153]

100 g (523 mmol) 6-Nitrocoumarin was dissolved in 600 ml dry ethanol, and the solution
was kept under an atmosphere of argon. 86 g (1.364 mol) ammonium formate and 6 g 10
% Pd-C were added with stirring, while the temperature rose to 45 °C and a gas evolution
was observed. The reaction mixture was heated with reflux for 3 hours and diluted
with another 200 ml ethanol. The hot mixture was filtered through Celite followed
by washing with 200 ml hot ethanol. The unprotected amine precipitated upon cooling,
filtered with suction, washed with hexane, and dried in vacuo. Another crop of the
amine was obtained by concentration of the filtrate.
Total yield of the intermediate amine was 74 g.
The crude amine was dissolved in 300 ml of a mixture of THF/H
2O 1:1 and kept under an atmosphere of argon. 110 g (504 mmol) Boc
2O and 95 g (687 mmol) dried potassium carbonate were added. The reaction mixture was
stirred overnight at room temperature, diluted with 750 ml water, and extracted with
ethyl acetate (3 x 1 l). The combined organic layers were dried over sodium sulfate
and concentrated in vacuo. The residue was dissolved in 2 L dichloromethane and stirred
in the presence of 1 kg silica gel, which was filtered with suction and washed with
dichloromethane. The filtrate was concentrated in vacuo to give the title compound.
An analytical sample was purified by chromatography on silica gel with dichloromethane.
Yield: 112 g (82 %) of pale yellow crystals,
m.p. 142-143 °C
Step B: Preparation of tert.-butyl (3,4-dihydro-2-oxo-2H-1-benzopyran-6-yl)carbamate,
an intermediate represented by the formula (202):
[0154]

85 g (325 mmol) of the coumarin from Step A were dissolved in a mixture of 1150 ml
ethanol and 115 ml acetic acid, and the solution was filled into a hydrogenation autoclave.
6 g 10 % Pd-C were added, and it was hydrogenated at room temperature and a pressure
of 20 atm hydrogen. After two days another 3 g Pd-C were added, and the reaction was
continued for two days. The catalyst was removed by filtration, and the filtrate was
concentrated in vacuo. The residue was dissolved in 1 L ethyl acetate, washed with
500 ml saturated aqueous sodium bicarbonate, dried over sodium sulfate, and the solvent
was removed in vacuo. The title lactone was purified by chromatography on silica gel
with dichloromethane containing 1 % ethanol.
Yield: 21 g (25 %) of colorless crystals,
m.p. 158-159 °C
Step C: Preparation of tert.-butyl rac-(3,4-dihydro-2-hydroxy-2H-1-benzopyran-6-yl)carbamate,
an intermediate represented by the formula (203):
[0155]

21 g (79.8 mmol) of the lactone from the previous Step was dissolved in 340 ml dry
dichloromethane and kept under an atmosphere of argon. The solution was cooled to
-70 °C and maintained at this temperature, while 67 ml of a 25 % solution of diisobutylaluminum
hydride (DIBAL-H) in toluene was added dropwise within 45 minutes. After an additional
hour stirring at this temperature 20 ml methanol were added slowly, and the mixture
was poured into 1 L saturated aqueous ammonium chloride solution. Solids were removed
by filtration through Celite and washed with dichloromethane. The filtrate was dried
over sodium sulfate, concentrated in vacuo to give the pure title compound as detected
by its
1H-NMR.
Yield: 16.5 g (78 %) of a yellow oil.
Step D: Preparation of ethyl rac-(6-(N-tert.-butoxycarbonylamino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (204):
[0156]

11.2 g (42.2 mmol) of the compound from Step C and 14.7 g (42.2 mmol) ethoxycarbonylmethylene
triphenylphosphorane were dissolved in 130 ml dry toluene and heated with reflux for
22 hours. The reaction mixture was cooled to room temperature, and 300 mg sodium hydride
were added. After additional 5 hours heating the mixture was poured into 1 L ice-cold
water. It was extracted three times with ethyl acetate, and the combined organic layers
were washed with 300 ml water, dried over sodium sulfate, and concentrated in vacuo.
The benzopyran (204) was obtained from the residue by chromatography on silica gel
with dichloromethane.
Yield: 5.5 g (39 %) of a colorless amorphous solid, m.p. 67-69°C
Step E: Preparation of ethyl rac-(6-(N-(4-cyanobenzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (205) :
[0157]

2.0 g (6.0 mmol) of the protected amine from the previous step was treated with 6
ml trifluoroacetic acid and stirred for 2 hours at room temperature. The mixture was
neutralized with saturated aqueous sodium bicarbonate solution and extracted with
ethyl acetate. The organic layer was dried over sodium sulfate and concentrated under
reduced pressure to leave a dark oil of unprotected ethyl rac-(6-amino-3,4- dihydro-2H-1-benzopyran-2-yl)acetate.
It was dissolved in 40 ml dry THF, treated with 4 ml dry pyridine and 1.0 g (6.0 mmol)
4-cyanobenzoyl chloride, and stirred overnight at room temperature. The mixture was
poured into ice-cold aqueous sodium bicarbonate solution and extracted with ethyl
acetate. The organic layer was washed successively with aqueous copper(II) sulfate
solution and with brine, dried over sodium sulfate, and concentrated in vacuo. The
nitrite (205) was obtained from the residue by chromatography on silica gel with dichloromethane/ethanol
96:4.
Yield: 1.4 g (64 %) of pale yellow crystals,
m.p.146-148 °C
Step F: Preparation of ethyl rac-(6-(N-(4-(aminoiminomethyl)benzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
hydrochloride
[0158] 1.4 g (3.8 mmol) of the nitrile from the previous Step was dissolved in 50 ml dry
ethanol. The solution was cooled with ice and saturated with gaseous hydrogen chloride.
After stirring overnight at room temperature the solvent was removed under reduced
pressure, and the residue was treated with a saturated solution of ammonia in ethanol.
The reaction mixture was stirred for three days, evaporated in vacuo, and the title
compound was obtained as a yellow oil by chromatography on silica gel with dichloromethane/ethanol
65:35 containing 5% ammonia in ethanol. A crystalline sample for analytical and biological
tests was obtained by stirring with a mixture of ethanol/etheral hydrogen chloride/ether.
Yield: 0.9 g (56 %) of yellow crystals, m.p. 253 °C (dec.)
Example 4
Preparation of rac-(6-(N-(4-(Aminoiminomethyl)benzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (206):
[0159]

0.2 g (0.48 mmol) of the ester from Example 47 were added to a mixture of 4 ml ethanol
and 0.5 ml 2 N aqueous sodium hydroxide. The mixture was diluted with water until
it became a clear solution. After slight warming it was stirred at room temperature
for 3 hours and acidified with 2 N acetic acid, while a precipitate was formed, which
was filtered, washed with water, and dried in vacuo. The very unsoluble compound (206)
was characterized by elemental analysis and mass spectrum.
Yield: 0.16 g (95 %) of a colorless amorphous solid,
m.p. 291-292°C (dec.).
Example 5
Preparation of rac-(6-(N-(4-Carbamoylbenzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (207):
[0160]

Method A:
[0161] 0.47 g (1.12 mmol) of the ester from Example 3 were added to a mixture of 5 ml ethanol
and 5 ml 2 N aqueous sodium hydroxide. The mixture was heated on a steam bath for
15 minutes, cooled to room temperature, and brought to pH 4 with 2 N aqueous hydrochloric
acid, while a precipitate was formed. The precipitate was filtered with suction, and
the amide (207) was purified by suspension in a small amount of hot ethanol.
Yield: 60 mg (15 %) of a beige amorphous solid,
m.p. 273-274°C
Method B:
[0162] 0.7 g (1.92 mmol) of the nitrile from Example 3, Step E were dissolved in 15 ml 98
% formic acid, and a stream of gaseous hydrogen chloride was passed through the mixture
for 4 hours. The reaction mixture was stirred overnight at room temperature, and the
solvent was removed in vacuo. The remaining solids were stirred with water, filtered
with suction, and washed with ethanol and ether, successively. The amide was suspended
in hot ethanol, filtered, and dried in vacuo.
Yield: 0.45 g (66 %) of grey crystals,
m.p. 264-265°C.
Example 6
Preparation of Ethyl rac-3-(6-(N-(4-(Aminoiminomethyl)benzoyl)amino)-3,4-dihydro-2-methyl-2H-1-benzopyran-2-yl)propanoate
hydrochloride, a compound represented by formula (208):
[0163]

Step A: Preparation of ethyl rac-3-(3,4-dihydro-2-methyl-6-nitro-4-oxo-2H-1-benzopyran-2-yl)propanoate,
an intermediate represented by the formula (209):
[0164]

5.4 g (29.8 mmol) 2-hydroxy-5-nitroacetophenone (prepared by methods from J. Am.
Chem. Soc. 1954, 76, 4993, the disclosure of which is incorporated herein by reference),
5.8 g (40.2 mmol) ethyl 4-oxopentanoate, and 1.7 ml pyrrolidine were dissolved in
50 ml toluene, and the mixture was heated for 6 hours with azeotropic removal of water.
The mixture was concentrated in vacuo, and the remaining oil was dissolved in ethyl
acetate. The solution was washed with 1 N aqueous hydrochloric acid and with brine,
successively, dried over sodium sulfate, and the solvent was removed under reduced
pressure. The chromanone (209) crystallized from the residue.
Yield: 5.3 g (58 %) of a pale yellow amorphous solid, m.p.
88-90°C.
Step B: Preparation of ethyl 3-(3,4-dihydro-4-hydroxy-2-methyl-6-nitro-2H-1-benzopyran-2-yl)propanoate,
an intermediate represented by the formula (210):
[0165]

3.2 g (10.4 mmol) of the chromanone from Step A were dissolved in 100 ml ethanol.
0.76 g (20.0 mmol) sodium borohydride were added in small portions, and the mixture
was stirred at room temperature for 5 hours. The reaction mixture was concentrated
in vacuo, acidified with 1 N aqueous hydrochloric acid, and extracted with ethyl acetate.
The organic layer was dried over sodium sulfate, and the solvent removed under reduced
pressure. The benzopyran (210) was obtained by chromatography on silica gel with dichloromethane
containing 4 % ethanol.
Yield: 2.0 g (62 %) of an oil.
Step C: Preparation of ethyl rac-3-(2-methyl-6-nitro-2H-1-benzopyran-2-yl)propanoate,
an intermediate represented by the formula (211) :
[0166]

2.0 g (6.5 mmol) of the alcohol from the previous step were dissolved in 75 ml toluene,
and a catalytic amount of 4-toluenesulfonic acid was added. The mixture was heated
with reflux for 7 hours, while water was removed azeotropically. The reaction mixture
was washed with aqueous sodium bicarbonate solution, the organic layer dried over
sodium sulfate, and concentrated in vacuo. The title chromene was obtained from the
residue by chromatography on silica gel with ethyl acetate/hexane 1:3.
Yield: 0.85 g (45 %) of an oil
Step D: Preparation of ethyl rac-3-(6-amino-3,4-dihydro-2-methyl-2H-1-benzopyran-2-yl)propanoate,
an intermediate represented by the formula (212):
[0167]

1.6 g (5.5 mmol) of the 6-nitrochromene from the previous Step was dissolved in a
mixture of 20 ml ethanol and 10 ml acetic acid. 400 mg Pd-C were added and the mixture
was filled into an autoclave. It was stirred overnight at room temperature under an
atmosphere of 20 bar hydrogen until the reduction was complete. The catalyst was removed
by filtration, and ethanol was distilled in vacuo. The reaction mixture was diluted
with ethyl acetate, washed with concentrated aqueous sodium bicarbonate solution,
dried over sodium sulfate, and concentrated under reduced pressure to give the crude
title amine, which was pure as detected by
1H-NMR.
Yield: 1.6 g of an oil, which darkened upon standing.
Step E: Preparation of ethyl rac-3-(6-(N-(4-cyanobenzoyl)amino)-3,4-dihydro-2-methyl-2H-1-benzopyran-2-yl)propanoate,
a compound represented by the formula (213):
[0168]

1.6 g (6.1 mmol) of the crude amine from Step D were dissolved in 40 ml dry THF.
5ml dry pyridine and 1.0 g (6.0 mmol) 4-cyanobenzoyl chloride were added successively.
The mixture was stirred overnight at room temperature and poured into an ice-cold
solution of aqueous sodium bicarbonate. It was extracted with ethyl acetate, and the
organic layer was washed with aqueous copper(II) sulfate and wich brine, dried over
sodium sulfate, and concentrated in vacuo. The pure nitrile was obtained by chromatography
on silica gel with dichloromethane/ethanol 97:3.
Yield: 1.5 g (63 %) of a dark viscous oil.
Step F: Preparation of ethyl rac-3-(6-(N-(4-(aminoiminomethyl)benzoyl)amino)-3,4-dihydro-2-methyl-2H-1-benzopyran-2-yl)propanoate
hydrochloride
[0169] 1.5 g (3.8 mmol) of the nitrite from Step E were dissolved in 50 ml dry ethanol.
The solution was cooled with an ice bath, saturated with gaseous hydrogen chloride,
and stirred overnight at room temperature. The reaction mixture was concentrated under
reduced pressure, and the residue was treated with a saturated solution of ammonia
in ethanol. It was stirred for additional 24 hours at room temperature, concentrated
in vacuo, and chromatographed on silica gel with dichloromethane/ethanol 65:35 containing
5 % saturated ammonia in ethanol to give the title amidine as an oil. A crystalline
sample for analytical and biological tests was obtained by stirring in a mixture of
ethanol/etheral hydrogen chloride/ether.
Yield: 0.94 g (55 %) of yellow crystals,
m.p. 118-120°C
Example 7
Preparation of rac-3-(6-(N-(4-Carbamoylbenzoyl)amino)-3,4-dihydro-2-methyl-2H-1-benzopyran-2-yl)propanoic
Acid, a compound represented by the formula (214):
[0170]

0.5 g (1.12 mmol) of the ester from Example 6 was added to a mixture of 5 ml 2N aqueous
sodium hydroxide and 5 ml ethanol. The reaction mixture was stirred with heating on
a steam bath for 20 minutes, while the mixture became a clear solution, and was then
brought to pH 4 with 2N aqueous hydrochloric acid, and extracted with ethyl acetate.
The organic layer was dried over sodium sulfate and concentrated in vacuo. The reaction
mixture was purified by chromatography on silica gel with chloroform/ethanol 1:1.
The remaining oil obtained from the pure fractions was treated with 2 ml trifluoroacetic
acid and stirred for 2 hours at room temperature. The solvent was removed under reduced
pressure, and the title amide crystallized from the residue by treating with ethanol.
Yield: 70 mg (16 %) of a beige amorphous solid,
m.p. 237-238°C.
Example 8
Preparation of Ethyl rac-3-(6-(4-(Aminoiminomethyl)phenylmethoxy)-2-methyl-2H-1-benzopyran-2-yl)propanoate
hydrochloride, a compound represented by the formula (215):
[0171]

Step A: Preparation of 4-((3-acetyl-4-hydroxyphenoxy)methyl)benzonitrile, an intermediate
represented by the formula (216):
[0172]

45 g (296 mmol) 2,5-dihydroxyacetophenone and 58.4 g (298 mmol) 4-cyanobenzyl bromide
were dissolved in 650 ml dry acetone, and 45 g (326 mmol) potassium carbonate and
4.5 g potassium iodide were added. After heating with reflux for 6.5 hours the inorganic
solids were removed by filtration and washed with acetone. The combined filtrates
were concentrated in vacuo, and the residue was stirred with 600 ml hot methanol.
The methanol solution was cooled to room temperature, and the compound (216) was filtered
with suction, washed successively with methanol and hexane, and dried in vacuo at
40 °C.
Yield: 69.5 g (88 %) of beige crystals,
m.p. 123-127°C
Step B: Preparation of ethyl rac-3-(6-(4-cyanophenylmethoxy)-3,4-dihydro-2-methyl-4-oxo-2H-1-benzopyran-2-yl)propanoate,
an intermediate represented by the formula (217):
[0173]

30 g (112.2 mmol) of the acetophenone from the previous Step, 20.4 g (141.5 mmol)
ethyl 4-oxopentanoate, and 9.6 ml pyrrolidine were dissolved in 500 ml dry toluene.
The mixture was stirred 20 hours at room temperature followed by 5.5 hours heating
with azeotropic removal of water. The mixture was concentrated under reduced pressure,
and the remaining oil was stirred for 30 minutes in 200 ml aqueous 2N hydrochloric
acid. It was extracted with dichloromethane, and the organic layer was washed successively
with 2N hydrochloric acid, water, and with brine. It was then dried over 0.4 nm mole
sieve and concentrated in vacuo to leave a brown oil, which was chromatographed on
silica gel with dichloromethane. The oily benzopyran (217) solidified by stirring
with aqueous 2N hydrochloric acid. It was filtered with suction, washed successively
with water and hexane, and dried in vacuo.
Yield: 12.27 g (28 %) of yellow crystals,
m.p. 88-92°C
Step C: Preparation of ethyl 3 - (6-(4-cyanophenylmethoxy)-3,4-dihydro-4-hydroxy-2-methyl-2H-1-benzopyran-2-yl)propanoate,
an intermediate represented by the formula (218):
[0174]

0.8 g (2.0 mmol) of the chromanone from Step B were dissolved in 10 ml dry ethanol,
and 40 mg (1.06 mmol) sodium borohydride were added. After stirring overnight at room
temperature another 40 mg of the hydride were added, and stirring was continued for
4 hours until the reduction was complete. The solvent was removed in vacuo, and the
residue was treated with a mixture of water and dichloromethane. The aqueous layer
was extracted with dichloromethane, and the combined organic layers were dried over
0.4 nm mole sieve. After concentration under reduced pressure the benzopyran was obtained
by chromatography on silica gel with dichloromethane containing up to 2 % ethanol.
Yield: 0.46 g (57 %) of an oil.
Step D: Preparation of ethyl rac-3-(6-(4-cyanophenylmethoxy)-2-methyl-2H-1-benzopyran-2-yl)propanoate,
an intermediate represented by the formula (219):
[0175]

380 mg (0.96 mmol) of the compound from the previous step were dissolved in 25 ml
toluene. After addition of a catalytic amount of 4-toluenesulfonic acid the mixture
was heated for 1 hour with azeotropic removal of water until the reaction was complete.
It was washed two times with saturated aqueous sodium bicarbonate, dried over 0.4
nm mole sieve, and concentrated in vacuo. The crude chromene was purified by chromatography
on silica gel with dichloromethane.
Yield: 230 mg (63 %) of an oil.
Step E: Preparation of ethyl rac-3-(6-(4-(aminoiminomethyl)phenylmethoxy)-2-methyl-2H-1-benzopyran-2-yl)propanoate
hydrochloride
[0176] 1.5 g (4.0 mmol) of the nitrile from the previous Step were dissolved in 100 ml dry
ethanol. The solution was cooled to 5-10 °C, saturated with hydrogen chloride, stirred
at room temperature overnight, and concentrated in vacuo. The remaining brown oil
was treated with 100 ml saturated ethanolic solution of ammonia and stirred for two
days. The solvent was removed in vacuo, and the title amidine was obtained from the
residue by chromatography on silica gel with dichloromethane/ethanol 95:5 and ascending
polarity up to 80:20.
Yield: 1.19 g (69 %) of a yellow, amorphous solid;
m.p. < 50 °C
Example 9
Preparation of rac-3-(6-(4-(Aminoiminomethyl)phenylmethoxy)-2-methyl-2H-1-benzopyran-2-yl)propanoic
acid hydrochloride, a compound represented by the formula (220):
[0177]

200 mg (0.464 mmol) of the ester from Example 52 were dissolved in 5 ml ethanol.
Two drops of water and 0.64 ml of a 0.9 N ethanolic sodium ethoxide solution were
added, and the mixture was stirred for 3 hours at 50 °C. After addition of the same
amount of sodium ethoxide, the reaction was continued for 2 hours at 50 °C and for
three days at room temperature. A precipitate had been formed, which was filtered
with suction, washed successively with ethanol and hexane. The crude solid was heated
in a mixture of 4 ml water and 1 ml aqueous 2N hydrochloric acid for some minutes
and stirred for 2 hours at room temperature. The mixture was evaporated to dryness,
and the title hydrochloride was suspended three times in 3 ml hot isopropanol. The
hot solutions were decanted, combined, and concentrated to dryness. It was washed
two times with ether, and dried in vacuo.
Yield: 68 mg (36 %) of a beige, amorphous solid,
m.p. 56°C.
Example 10
Preparation of rac-(3,4-Dihydro-6-(4-(piperidin-4-yl)butoxy)-2H-1-benzopyran-2-yl)acetic
acid trifluoroacetate, a compound represented by the formula a (225) :
[0178]

Step A: Preparation of ethyl rac-(6-(4-(1-(tert.-butoxycarbonyl)piperidin-4-yl)butoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (226):
[0179]

0.92 g (3.9 mmol) ethyl rac-(3,4-dihydro-6-hydroxy-2H-1-benzopyran-2-yl)acetate (prepared
according to Eur. Pat. Appl. EP 129 906, the disclosure of which is incorporated herein
by reference) were dissolved in 25 ml dry DHF. The solution was cooled to -5 °C, and
1.8 ml 40 % benzyltrimethylammonium hydroxide (Triton B) in methanol were added dropwise.
After 40 minutes at this temperature 1.25 g (3.9 mmol) 4-(4-bromobutyl)-1-(tert.-butoxycarbonyl)piperidine
(prepared according to Eur. Pat. Appl. EP 478 328, the disclosure of which is incorporated
herein by reference) were added. The mixture was stirred at -5 °C for additional 3
hours, warmed to room temperature, stirred overnight, and poured into 150 ml ethyl
acetate. It was then washed with water, 1 N aqueous hydrochloric acid, water, saturated
aqueous sodium bicarbonate, water, and with brine, successively. The organic layer
was dried over sodium sulfate and concentrated in vacuo. The title compound was obtained
by chromatography on silica gel with hexane/ethyl acetate 4:1.
Yield: 0.64 g (35 %) of a colorless oil.
Step B: Preparation of rac-(6-(4-(1-(tert.-butoxycarbonyl)piperidin-4-yl)butoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
acid, an intermediate represented by the formula (227):
[0180]

0.64 g (1.35 mmol) of the ester from Step A were dissolved in 10 ml ethanol, and
5.6 ml of a 1 N ethanolic solution of sodium ethoxide were added. The reaction mixture
was stirred at room temperature for seven days and concentrated to dryness under reduced
pressure. The residue was treated with water and neutralized with 10 % aqueous KHSO
4 solution. It was extracted with ethyl acetate. The organic layer was dried over sodium
sulfate, and the solvent was removed in vacuo to give the pure carboxylic acid.
Yield: 0.58 g (96 %) of a pale yellow oil, which slowly solidified upon standing
Step C: Preparation of rac-(3,4-dihydro-6-(4-(piperidin-4-yl)butoxy)-2H-1-benzopyran-2-yl)acetic
acid trifluoroacetate
[0181] 0.4 g (0.9 mmol) of the protected piperidine from the previous Step were treated
with 6 ml trifluoroacetic acid. The mixture was stirred for 2 hours at room temperature
and evaporated in vacuo. After addition of water it was extracted with ether, and
the organic layer was dried over sodium sulfate and concentrated under reduced pressure.
The title compound was purified by chromatography on silica gel with dichloromethane/ethanol
96:4.
Yield: 120 mg (29 %) of a beige oil, which solidified in part upon standing.
Example 11
Preparation of rac-(6-(5-(Aminoiminomethyl)pentoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
acid trifluoroacetate, a compound represented by the formula (253):
[0182]

Step A: Preparation of ethyl rac-(6-(5-cyanopentoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (254):
[0183]

2.19 g (9.27 mmol) ethyl rac-(3,4-dihydro-6-hydroxy-2H-1-benzopyran-2-yl)acetate
(prepared according to Eur. Pat. Appl. EP 129 906, the disclosure of which is incorporated
herein by reference) and 2.0 g (11.4 mmol) 6-bromocapronitrile were dissolved in 30
ml dry acetone. 2.0 g (14.5 mmol) potassium carbonate, 250 mg potassium iodide, and
100 mg triethylbenzylammonium chloride were added, and the mixture was heated with
reflux for 10 hours followed by stirring at room temperature for two days. The inorganic
solid was removed by filtration and washed with acetone, and the combined filtrates
were concentrated in vacuo. The nitrile (254) was obtained from the residue by chromatography
on silica gel with dichloromethane containing up to 4 % ethanol.
Yield: 1.32 g (43 %) of an oil.
Step B: Preparation of ethyl rac-(6-(5-(aminoiminomethyl)pentoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
hydrochloride, an intermediate represented by the formula (255):
[0184]

1.25 g (3.77 mmol) of the nitrile from Step A were dissolved in 50 ml dry ethanol.
The solution was cooled to 0 °C and saturated with hydrogen chloride. After stirring
overnight it was concentrated in vacuo. The residue was treated with a mixture of
10 ml liquid ammonia and 50 ml dry ethanol and stirred overnight at room temperature.
The solvent was removed under reduced pressure, and the remaining material was stirred
with ethanol and dichloromethane, successively. Solids were removed by filtration
after each procedure, and the filtrates were concentrated under reduced pressure.
The crude title compound from the last filtrate was purified by chromatography on
silica gel with dichloromethane/ethanol 9:1 followed by 8:2.
Yield: 0.97 g (67 %) of a white powder,
m.p. 82-84°C.
Step C: Preparation of ethyl rac-(6-(5-(N-tert.-butoxycarbonylaminoiminomethyl)pentoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (256):
[0185]

0.7 g (1.82 mmol) of the amidine from Step B were dissolved in 11 ml THF/H
2O 1:1. After addition of 335 mg (2.42 mmol) potassium carbonate and 0.4 g (1.83 mmol)
Boc
2O the mixture was stirred overnight at room temperature. It was diluted with 25 ml
ethyl acetate. The aqueous layer was separated and extracted with ethyl acetate. The
combined organic layers were washed with water, dried over sodium sulfate, and concentrated
to dryness in vacuo to give the crude protected amidine, which was used for the next
Step.
Yield: 0.87 g of a yellow oil.
Step D: Preparation of rac-(6-(5-(N-tert.-butoxycarbonylaminoiminomethyl)pentoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
acid, an intermediate represented by the formula (257)
[0186]

A mixture of 13 ml ethanol and 6 ml 2 N aqueous sodium hydroxide was added to 0.81
g (1.81 mmol) of the ester from the previous Step. The mixture was stirred at room
temperature for 4 hours and neutralized with diluted acetic acid. After evaporation
in vacuo the residue was stirred with a mixture of dichloromethane/methanol 1:1. Solids
were removed by filtration and washed, and the combined filtrates were concentrated
under reduced pressure. The carboxylic acid (257) was obtained by chromatography on
silica gel with dichloromethane and enhancing the polarity by addition of 3 % ethanol.
Yield: 215 mg (28 %) of an oil.
Step E: Preparation of rac-(6-(5-(aminoiminomethyl)pentoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
acid trifluoroacetate
[0187] 112 mg (0.266 mmol) of the protected amidine from Step D were treated with 2.2 ml
trifluoroacetic acid, and the mixture was stirred at room temperature for 1 hour.
The solvent was removed in vacuo, and the residue was stirred with 10 ml water, while
the title compound precipitated. The product was filtered with suction, washed with
water and with ether, successively, and dried in vacuo. Another crop was obtained
from the combined filtrates, which were washed two times with ether and concentrated
under reduced pressure.
Total yield: 91 mg (79 %) of a beige powder,
m.p. 132-134°C.
Example 12
Preparation of rac-3-(6-(N-(4-(Aminoiminomethyl)benzoyl)amino)-3,4-dihydro-2-methyl-2H-1-benzopyran-2-yl)propanoic
Acid, a compound represented by the formula (258)
[0188]

0.4 g (0.9 mmol) of the ester from Example 50 were added to a mixture of 8 ml ethanol
and 0.5 ml 2 N aqueous sodium hydroxide. It was stirred overnight at room temperature,
diluted with 10 ml water, and brought to pH 4 with acetic acid. The title compound
precipitated from the solution. It was filtered, washed with water, and dried in vacuo.
Yield: 280 mg (82 %) of a colorless amorphous powder,
m.p. 278-280 °C (dec.).
Example 13
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(4-((methylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (260):
[0189]

Step A: Preparation of ethyl rac-(3,4-dihydro-6-(N-(4-(ethoxycarbonimidoyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate
hydrochloride, an intermediate represented by the formula (261):
[0190]

2.0 g (5.5 mmol) of the nitrile from Example 3, Step E were dissolved in 65 ml dry
ethanol. The solution was cooled with ice and saturated with gaseous hydrogen chloride.
It was stirred overnight at room temperature and concentrated under reduced pressure
to give the intermediate as a crystalline solid, which was used for the next step.
Yield: 2.4 g (98 %)
Step B: Preparation of ethyl rac-(3,4-dihydro-6-(N-(4-((methylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate
hydrochloride
[0191] 1.35 g (3.0 mmol) of the crude intermediate from the previous Step in 50 ml dry ethanol
were cooled with ice. It was neutralized with a 30 % ethanolic solution of methylamine
followed by 2 hours stirring. Another 5 ml of the methylamine solution were added,
and stirring was continued for 6 hours, while the temperature was maintained below
5 °C. A clear solution was obtained, which was concentrated under reduced pressure.
The title compound crystallized upon treating of the residue with ethanol, and was
purified by heating of an ethanolic suspension.
Yield: 0.9 g (69 %) of a yellow amorphous solid,
m.p. 278-279°C.
Example 14
Preparation of rac-(3,4-Dihydro-6-(N-(4-((methylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (262) :
[0192]

To 207 mg (0.48 mmol) of the ester from Example 13 were given 4 ml ethanol, 0.5 ml
2 N aqueous sodium hydroxide, and three drops of water, and the mixture was stirred
overnight at room temperature. A precipitate was formed. It was brought to pH 5 with
2 N acetic acid, and the title compound was filtered with suction, washed with water
and with ethanol, successively, and dried in vacuo.
Yield: 0.12 g (68 %) of a pale yellow powder,
m.p. 275-276°C (dec.).
Example 15
Preparation of Ethyl rac-(6-(N-(4-((Benzoylamino)iminomethyl)benzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
a compound represented by the formula (263):
[0193]

A solution of 0.42 g (1.0 mmol) of the ester from Example 47, 0.22 g triethylamine,
and 20 mg 4-dimethylaminopyridine in 20 ml dry dichloromethane was cooled to -20 °C,
and a solution of 0.15 g (1.1 mmol) benzoyl chloride in 2 ml dichloromethane was added
dropwise at this temperature. The mixture became clear by slow warming to room temperature,
and stirring was continued for 3 hours. After addition of water it was extracted with
ethyl acetate. The organic layer was dried over sodium sulfate and concentrated under
reduced pressure. The title benzoate was obtained by chromatography on silica gel
with dichloromethane/ethanol 96:4 as an oil. A crystalline sample for analytical and
biological tests was obtained by stirring with ether.
Yield: 0.21 g (43 %) of a beige powder,
m.p. 149-150°C (dec.).
Example 16
Preparation of rac-9-(6-Aminoiminomethyl-2-methyl-2H-1-benzopyran-2-yl)nonanoic acid,
a compound represented by the formula (264)
[0194]

Step A: Preparation of ethyl rac-9-(6-cyano-3,4-dihydro-2-methyl-4-oxo-2H-1-benzopyran-2-yl)nonanoate,
an intermediate represented by the formula (265) :
[0195]

5-Cyano-2-hydroxyacetophenone was prepared by rearrangement of 4-acetoxybenzonitrile
(Arch. Pharm. 1977, 310, 119, the disclosure of which is incorporated herein by reference)
and ethyl 10-oxoundecanoate by PdCl
2-catalyzed oxidation of ethyl 10-undecenoate (J. Organomet. Chem. 1987, 334, C 5,
the disclosure of which is incorporated herein by reference). 32.4 g (201 mmol) of
the acetophenone, 35.0 g (153.3 mmol) of the ester, and 7 ml pyrrolidine were dissolved
in 160 ml toluene. After standing at room temperature for 1 hour it was heated with
azeotropic removal of water for 8 hours. The solvent was removed in vacuo, and the
residue was dissolved in dichloromethane. It was washed with water, and the aqueous
layer was extracted with dichloromethane. The combined organic layers were dried over
sodium sulfate and concentrated under reduced pressure. The title chromanone was obtained
by chromatography on silica gel with dichloromethane.
Yield: 12.6 g (22 %) of an oil.
Step B: Preparation of ethyl 9-(6-cyano-3,4-dihydro-4-hydroxy-2-methyl-2H-1-benzopyran-2-yl)nonanoate,
an intermediate represented by the formula (266):
[0196]

12.6 g (33.9 mmol) of the chromanone from Step A were dissolved in 300 ml dry ethanol.
2.6 g (68.7 mmol) sodium borohydride were added in small portions, while the temperature
was kept below 25 °C. It was stirred overnight, concentrated in vacuo, hydrolyzed
with a mixture of ice and aqueous hydrogen chloride, and extracted with dichloromethane
for three times. The combined organic layers were dried over sodium sulfate and concentrated
under reduced pressure. The title benzopyran was obtained by chromatography on silica
gel with dichloromethane.
Yield: 11.2 g (88 %) of an oil.
Step C: Preparation of ethyl rac-9-(6-cyano-2-methyl-2H-1-benzopyran-2-yl)nonanoate, an
intermediate represented by the formula (267)
[0197]

11.2 g (30.0 mmol) of the compound from Step B were dissolved in 200 ml toluene.
A catalytic amount of p-toluenesulfonic acid was added, and it was heated with azeotropic
removal of water for 7 hours. The mixture was washed with saturated aqueous sodium
bicarbonate solution, dried over sodium sulfate, and concentrated under reduced pressure.
The title benzopyran was purified by chromatography on silica gel with dichloromethane.
Yield: 3.0 g (28 %) of an oil.
Step D: Preparation of ethyl rac-9-(6-aminoiminomethyl-2-methyl-2H-1-benzopyran-2-yl)
nonanoate hydrochloride, an intermediate represented by the formula (268) :
[0198]

1.5 g (4.2 mmol) of the chromene from the previous Step were dissolved in 50 ml dry
ethanol. The solution was saturated with hydrogen chloride and stirred overnight at
room temperature. The solvent was removed in vacuo, and the residue was treated with
a saturated solution of ammonia in ethanol. It was stirred overnight and concentrated
to dryness under reduced pressure to give the pure title amidine.
Yield: 1.4 g (81 %) of an oil.
Step E: Preparation of rac-9-(6-aminoiminomethyl-2-methyl-2H-1-benzopyran-2-yl)nonanoic
acid
[0199] 7 ml 2 N aqueous sodium hydroxide and 5 ml acetonitrile were added to 0.6 g (1.47
mmol) of the ester from the previous Step, and the mixture was heated for 30 minutes
on a steam bath. It was brought to pH 7 with 2 N acetic acid, while a precipitate
formed. It was filtered with suction, washed successively with ice-water and acetone,
and dried in vacuo. Yield: 0.4 g (79 %) of a white powder,
m.p. 223-225 °C (dec.).
Example 17
Preparation of rac-(3,4-Dihydro-6-(2-(piperidin-4-yl)ethoxy)-2H-1-benzopyran-2-yl)acetic
Acid Trifluoroacetate, a compound represented by the formula (269):
[0200]

Step A: Preparation of ethyl rac-(6-(2-(1-(tert.-butoxycarbonyl)piperidin-4-yl)ethoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (270) :
[0201]

To a solution of 2.2 g (7.5 mmol) 4-(2-bromoethyl)-1-(tert.-butoxycarbonyl)piperidine
(prepared by bromination of 2-(1-(tert.-butoxycarbonyl)piperidin-4-yl)ethanol according
to Eur. Pat. Appl. EP 478 328) in 50 ml dry acetonitrile were added 2.84 g (8.72 mmol)
dry cesium carbonate. After dropwise addition of a solution of 3.05 g (12.9 mmol)
ethyl rac-(3,4-dihydro-6-hydroxy-2H-1-benzopyran-2-yl)acetate (prepared according
to Eur. Pat. Appl. EP 129 906) in 20 ml dry acetonitrile it was stirred over night
at room temperature. Another 1 g cesium carbonate was added and stirring was continued
for 2 hours at 70 °C and overnight at room temperature. The mixture was filtered through
Celite, which was washed with acetonitrile and acetone. The filtrate was concentrated
under reduced pressure, and the residue was stirred with hexane/ethyl acetate 4:1
and two times with ethyl acetate, successively. The combined solutions, which had
been separated from insoluble material, were concentrated in vacuo, and the compound
(270) was obtained by chromatography on silica gel with hexane followed by hexane/ethyl
acetate 4:1.
Yield: 2.9 g (86 %) of a yellow oil, which solidified upon standing
Step B: Preparation of rac-(6-(2-(1-(tert.-butoxycarbonyl)piperidin-4-yl)ethoxy)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
acid, an intermediate represented by the formula (271)
[0202]

To a solution of 1.5 g (3.35 mmol) of the ester from the previous step in 100 ml
ethanol were added 6.8 ml 2 N aqueous sodium hydroxide, and the mixture was stirred
overnight at room temperature. It was adjusted to pH 5 with diluted acetic acid and
concentrated under reduced pressure. The title acid was obtained by chromatography
on silica gel with dichloromethane followed by addition of up to 3 % ethanol. Yield:
0.54 g (38 %) of a beige oil.
Step C: Preparation of rac-(3,4-dihydro-6-(2-(piperidin-4-yl)ethoxy)-2H-1-benzopyran-2-yl)acetic
acid trifluoroacetate
[0203] 117 mg (0.28 mmol) of the protected piperidine from Step B were stirred in 2.3 ml
trifluoroacetic acid at room temperature for 30 minutes, and it was concentrated to
dryness in vacuo to leave the pure title compound.
Yield: 115 mg (95 %) of a brown resin.
Example 18
Preparation of Ethyl rac-(6-(N-(4-((Aminoiminomethyl)amino)benzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an compound represented by the formula (283):
[0204]

4-Guanidinobenzoic acid hydrochloride was prepared from 4-aminobenzoic acid according
to a literature procedure (Recl. Trav. Chim. Pays-Bas 1953,
72, 643, the disclosure of which is incorporated herein by reference). It was heated
in thionyl chloride for one hour followed by concentration to dryness to give the
crude benzoyl chloride hydrochloride. 0.62 g (1.85 mmol) of the compound from Example
3, Step D were stirred for 1 hour at room temperature in 2 ml triflucroacetic acid,
and the mixture was concentrated to dryness in vacuo. The mixture was treated with
saturated aqueous sodium bicarbonate solution and extracted with ethyl acetate. The
organic layer was dried over sodium sulfate and concentrated under reduced pressure,
and the oily residue was dissolved in 20 ml dry pyridine followed by addition of 0.44
g (1.88 mmol) crude 4-guanidinobenzoyl chloride hydrochloride. After stirring overnight
at room temperature the mixture was poured into 100 ml water, while a precipitate
was formed, which was collected by filtration, washed with water, and dried in vacuo.
The title compound was purified by chromatography on silica gel with ethanol/concentrated
aqueous ammonia 85:15.
Yield: 0.15 g (20 %) of a brown amorphous solid
Example 19
Preparation of rac- (6- (N-(4-((Aminoiminomethyl)amino)benzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (284):
[0205]

0.08 g (0.2 mmol) of the ester from Example 18 were dissolved in 30 ml ethanol followed
by addition of 0.4 ml aqueous 2 N sodium hydroxide solution. The mixture was stirred
at room temperature for two days, and the mixture was concentrated to dryness under
reduced pressure. The residue was dissolved in water, and the solution was neutralized
with acetic acid, while the title acid precipitated. It was filtered with suction,
washed with water, and dried in vacuo.
Yield: 0.045 g (61 %) of a beige crystalline solid, m.p. 258-260°C.
Example 20
[BL-43]
Ethyl rac-3-(6-(4-(Aminoiminomethyl)phenylmethoxy)-3,4-dihydro-2-methyl-4-oxo-2H-1-benzopyran-2-yl)propanoate
hydrochloride, a compound represented by the formula (299):
[0206]

Example 21
rac-3-(6-(4-(Aminoiminomethyl)phenylmethoxy)-3,4-dihydro-2-methyl-4-oxo-2H-1-benzopyran-2-yl)propanoic
Acid hydrochloride, a compound represented by the formula (300):
[0207]

Example 22
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(4-((ethoxycarbonylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate,
a compound represented by the formula (303) :
[0208]

418 mg (1 mmol) of the benzopyran from Example 3, 0.3 ml triethylamine, and 20 mg
4-dimethylaminopyridine were dissolved in 20 ml dry dichloromethane, and the solution
was cooled to -20 °C. 119 mg (1.1 mmol). Ethyl chloroformate in 2 ml dry dichloromethane
was added dropwise at this temperature, and after 30 min it was warmed to room temperature
and stirred for additional 2 hours. The mixture was poured into ice-cold water, and
the organic layer was dried over sodium sulfate and concentrated under reduced pressure.
The remaining crystalline title compound was stirred with ether, filtered, and dried
in vacuo.
Yield: 360 mg (79 %) of a pale yellow solid,
m.p. 163-165°C.
Example 23
Preparation of Ethyl rac-(6-(N-(4-(Aminoiminomethyl)-2-fluorobenzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (304):
[0209]

Step A: Preparation of ethyl rac-(6-(N-(4-cyanc-2-fluorobenzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (307):
[0210]

5.0 g (30.3 mmol) of the acid 119 were heated for 1 hour with reflux in 50 ml thionyl
chloride containing one drop of DMF. The reaction mixture was concentrated under reduced
pressure, and the crude acid chloride was dissolved in 130 ml dry THF. This solution
was added dropwise at 0 °C to crude ethyl (6-amino-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
in 200 ml dry THF and 20 ml dry pyridine, which had been obtained according to Example
3, Step E from 10.0 g (29.8 mmol) of the protected derivative with 20 ml trifluoroacetic
acid. After stirring overnight at room temperature the mixture was poured into ice-cold
water containing sodium bicarbonate. The precipitate of the title nitrile was filtered
with suction, heated for some minutes in ethanol, filtered again after cooling, and
the crystals were washed with hexane and dried in vacuo.
Yield: 8.6 g (75 %) of a beige amorphous solid,
m.p. 154-155°C.
Step B: Preparation of ethyl rac-(6-(N-(4-(aminoiminomethyl)-2-fluorobenzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
hydrochloride
[0211] 4.5 g (11.8 mmol) of the nitrile from the previous Step in 150 ml dry ethanol were
cooled to 0 °C and saturated with gaseous hydrogen chloride. After stirring overnight
at room temperature it was concentrated under reduced pressure. The crystalline residue
was treated with 150 ml of a saturated ethanolic solution of ammonia and stirred again
overnight. The crude title compound was obtained after concentration in vacuo, recrystallized
from ethanol followed by crystallization from a mixture of ethanol/water/ether. Yield: 3.0
g (58 %) of a pale yellow powder,
m.p. 198-200°C.
Example 24
Preparation of rac-(6-(N-(4-(Aminoiminomethyl)-2-fluorobenzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (308):
[0212]

1.2 g (2.75 mmol) of the ester from Example 23 were stirred overnight at room temperature
in a mixture of 20 ml ethanol and 5 ml 2 N aqueous sodium hydroxide solution. It was
brought to pH 4 with 2 N acetic acid, and the precipitate of the title compound was
filtered with suction, washed successively with water and with acetone, and dried
in vacuo at 50 °C.
Yield: 0.84 g (82 %) of a pale yellow powder,
m.p. 250°C.
Example 25
Preparation of Ethyl rac- (3,4-Dihydro-6- (N-(4-((ethylamino)iminomethyl)benzoyl)amino)-2H-1-benzozpyran-2-yl)acetate
hydrochloride, a compound represented by the formula (309):
[0213]

1.8 g (4.0 mmol) of the crude intermediate of Example 13, Step A were dissolved in
50 ml ethanol. The solution was cooled with ice, and 2 ml of a 50 % ethanolic solution
of ethylamine were added. It was stirred overnight at room temperature, and the solvent
was removed under reduced pressure. The residue was stirred with a small amount of
ethanol to give the pure crystalline title compound, which was filtered and dried
in vacuo.
Yield: 1.6 g (89 %) of a pale yellow powder,
m.p. 290-291°C.
Example 26
Preparation of rac-(3,4-Dihydro-6-(N-(4-((ethylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetic
acid, a compound represented by the formula (310) :
[0214]

0.8 g (1.8 mmol) of the ester from Example 25 were suspended in a mixture of 16 ml
ethanol, 2 ml 2 N aqueous sodium hydroxide, and some drops of water. It was stirred
overnight at room temperature, while the suspension became a solution, which was brought
to pH 5 with 2 N acetic acid. The precipitate of the pure title compound was collected
by filtration, washed successively with water and acetone, and dried in vacuo.
Yield: 0.65 g (95 %) of a yellow powder,
m.p. 260-262 °C(dec.).
Example 27
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(4-((dimethylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (311):
[0215]

1.8 g (4.0 mmol) of the crude intermediate of Example 13, Step A were dissolved in
50 ml ethanol. The solution was cooled with ice, and 2 ml of a 50 % ethanolic solution
of dimethylamine were added. It was stirred overnight at room temperature, and the
solvent was removed under reduced pressure. The residue was stirred with a small amount
of ethanol to give the pure crystalline title compound, which was filtered and dried
in vacuo.
Yield: 1.35 g (75 %) of a white powder,
m.p. 248°C.
Example 28
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(4-((methoxycarbonylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate,
a compound represented by the formula (312):
[0216]

To 417 mg (1.0 mmol) of the amidine from Example 3, 0.3 ml triethylamine, and 20
mg 4-dimethylaminopyridine in 40 ml dichloromethane were added at 0°C 104 mg (1.1
mmol) methyl chloroformate, and the mixture was stirred overnight at room temperature.
A white precipitate was formed, which was collected by filtration and chromatographed
on silica gel with dichloromethane/ethanol 9:1 to give the pure title carbamate.
Yield: 0.21 g (48%) of a white powder,
m.p. 204-206 °C
Example 29
Preparation of Ethyl rac-(6-(N-(4-(Aminoiminomethyl)-2-chlorobenzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
Hydrochloride, a compound represented by the formula (313):
[0217]

Step A: Preparation of ethyl rac-(6-(N-(2-chloro-4-cyanobenzoyl) amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (314):
[0218]

3.0 g (8.94 mmol) of the benzopyran from Example 3, Step D were stirred with 6 ml
trifluoroacetic acid for 2 hours at room temperature. The mixture was treated with
saturated aqueous sodium bicarbonate solution and extracted with ethyl acetate. The
organic layer was dried over sodium sulfate, and the solvent was removed in vacuo
to give the crude unprotected aminobenzopyran, which was dissolved in a mixture of
50 ml dry THF and 8 ml dry pyridine. 50 ml of a solution of crude 2-chloro-4-cyanobenzoyl
chloride in dry THF, which had been prepared from 1.1 g (6.1 mmol) 2-chloro-4-cyanobenzoic
acid (Chem. Ber. 1936,
69, 537, the disclosure of which is incorporated herein by reference) according to Example
62, Step A, was added dropwise at 0 °C. After stirring overnight at room temperature
the mixture was poured into ice-cold water containing sodium bicarbonate. It was extracted
with ethyl acetate, and the organic layer was washed successively with aqueous Cu(II)
sulfate solution and with brine, dried over sodium sulfate, and concentrated under
reduced pressure. The nitrile (314) was obtained from the residue by chromatography
on silica gel with chloroform/methanol 96:4. It crystallized from the pure fractions
after stirring with a small amount of ethanol. Yield: 1.1 g (46 %) of beige crystals,
m.p. 152-154°C.
Step B: Preparation of ethyl rac-(6-(N-(4-(aminoiminomethyl)-2-chlorobenzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
hydrochloride:
[0219] 1.1 g (2.76 mmol) of the nitrile from the previous Step were dissolved in 25 ml ethanol,
and the solution was cooled to 0 °C and saturated with gaseous hydrogen chloride.
It was stirred overnight at room temperature followed by concentration under reduced
pressure. The residue was treated with 20 ml of a saturated solution of ammonia in
ethanol, and again it was stirred overnight. After removal of the solvent in vacuo
the remaining title compound was recrystallized from ethanol/water/ether.
Yield: 0.9 g (72 %) of a pale yellow powder,
m.p. 225-226°C.
Example 30
Preparation of rac-(6-(N-(4-(Aminoiminomethyl)-2-chlorobenzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
acid, a compound represented by the formula (314) :
[0220]

0.3 g (0.66 mmol) of the ester from Example 29 were stirred overnight at room temperature
with a mixture of 5 ml ethanol and 0.5 ml 2 N aqueous sodium hydroxide solution. It
was brought to pH 5 with 2 N acetic acid. The precipitate of the title compound was
filtered with suction, washed successively with water and with acetone, and dried
in vacuo.
Yield: 0.19 g (74 %) of a white powder,
m.p. 269-270°C(dec.).
Example 31
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(3-(piperidine-4-yl)propenoyl)amino)-2H-1-benzopyran-2-yl)acetate
Trifluoroacetate, a compound represented by the formula (327):
[0221]

Step A: Preparation of ethyl rac-(6-(N-(3-(1-(tert.-butoxycarbonyl)piperidine-4-yl)propenoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (329):
[0222]

0.85 g (3.33 mmol) of the acid 386 were dissolved in a mixture of 23 ml dry dichloromethane
and 0.25 ml dry DMF. The solution was kept at a temperature between -10 °C and 0 °C,
while 0.46 g (3.6 mmol) oxalyl chloride were added slowly. After stirring for 40 minutes
at this temperature the mixture was added dropwise to a solution of 0.5 ml triethylamine
and crude ethyl (6-amino-3,4-dihydro-2H-1-benzopyran-2-yl)acetate (prepared with trifluoroacetic
acid from 1.5 g (4.5 mmol) of the Boc-protected amine as described in Example 3) in
35 ml dry dichloromethane. After stirring for 90 minutes at this temperature the mixture
was poured into ice-cold water, and the aqueous layer was extracted with dichloromethane.
The combined organic layers were washed with water, dried over sodium sulfate, and
concentrated under reduced pressure. The title compound was purified by chromatography
on silica gel with dichloromethane/ethanol 80:1.
Yield: 0.81 g (51 %) of an oil.
Step B: Preparation of ethyl rac-(3,4-dihydro-6-(N-(3-(piperidine-4-yl)propenoyl)amino)-2H-1-benzopyran-2-yl)acetate
trifluoroacetate
[0223] 0.81 g (1.71 mmol) of the protected piperidine from the previous Step were stirred
for 2 hours at room temperature in 6 ml trifluoroacetic acid. It was poured into ice-cold
water, adjusted to pH 7 with sodium bicarbonate, and extracted with dichloromethane.
The organic layer was dried over sodium sulfate and concentrated under reduced pressure,
and the residue was stirred with a mixture of hexane and ether to give the crystalline
title compound, which was collected by filtration, and dried at 50 °C in vacuo.
Yield: 0.18 g (22 %) of reddish crystals,
m.p. 72-73°C.
Example 32
Preparation of rac-(3,4-Dihydro-6-(N-(3-(piperidine-4-yl)propenoyl)amino)-2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (330) :
[0224]

0.1 g (0.2 mmol) of the ester from Example 31 were stirred overnight at room temperature
in a mixture 2.5 ml ethanol and 0.35 ml 2 N aqueous sodium hydroxide solution. The
reaction mixture was cooled with ice and brought to pH 5.5 with 2 N acetic acid. The
precipitate of the title acid was filtered with suction, washed with a small amount
of cold water, and dried at 50 °C in vacuo.
Yield: 42 mg (59 %) of beige crystals,
m.p. 175-178°C.
Example 33
Preparation of Ethyl rac-(6-(N-(4-(Aminoiminomethyl)benzoyl)amino)-3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-2-yl)acetate
Hydrochloride, a compound represented by the formula (331) :
[0225]

Step A: Preparation of tert.-butyl (3,4-dihydro-4,4-dimethyl-2-oxo-2H-1-benzopyran-6-yl)carbamate,
an intermediate represented by the formula (332):
[0226]

To a suspension of 1.5 g 10 % Pd-C in 300 ml ethanol were added under an atmosphere
of argon 29.2 g (132.0 mmol) 3,4-dihydro-4,4-dimethyl-6-nitro-2-oxo-2H-1-benzopyran
(prepared by nitration of 3,4-dihydro-4,4-dimethyl-2-oxo-2H-l-benzopyran according
to J. Am. Chem. Soc. 1970,
92, 4377, the disclosure of which is incorporated herein by reference) and 21.4 g (339.4
mmol) ammonium formate. The temperature raised for approximately 1 hour to 50 °C accompanied
by a gas evolution, and it was heated for additional 3 hours at 80 °C. The catalyst
was filtered through Celite, which was washed with 500 ml hot ethanol. The combined
filtrates were concentrated under reduced pressure to a volume of 100 ml, and the
formed precipitate was filtered with suction. A second crop of the crude 6-amino-3,4-dihydro-4,4-dimethyl-2-oxo-2H-1-benzopyran
was obtained after further concentration. Both crops were combined and dissolved in
80 ml THF followed by addition of 80 ml water, 25.3 g (183 mmol) potassium carbonate,
and 29.2 g (133.8 mmol) Boc
2O. After 8 hours stirring at room temperature another 2.9 g Boc
2O and 2.5 g potassium carbonate were added, and stirring was continued overnight.
The mixture was poured into 300 ml water and extracted with ethyl acetate, and the
organic layer was dried over sodium sulfate and concentrated under reduced pressure.
A first crop of the title compound crystallized from the oily residue with diisopropylether.
An additional amount was obtained from the concentrated mother liquid by chromatography
on silica gel with toluene crystallizing from the oily pure fractions with diisopropylether.
Total yield: 31.6 g (82 %) of colorless crystals,
m.p. 106-108°C.
Step B: Preparation of tert.-butyl rac-(3,4-dihydro-4,4-dimethyl-2-hydroxy-2H-1-benzopyran-6-yl)carbamate,
an intermediate represented by the formula (333):
[0227]

31.6 g (108.5 mmol) of the benzopyran from the previous Step were dissolved in 450
ml dry THF and cooled to -70 °C under an atmosphere of argon. At this temperature
133 ml of a 25 % solution of DIBAH in toluene was added dropwise within 1 hour, and
the mixture was stirred for additional 2 hours. It was quenched carefully with 35
ml methanol and warmed to room temperature, and the mixture was poured into 1000 ml
saturated aqueous ammonium chloride solution. After vigorous stirring the upper organic
layer solidified to a gel, which was separated and stirred with 1000 ml ethyl acetate.
It was then filtered through Celite and washed with 500 ml ethyl acetate. The combined
filtrates were dried over sodium sulfate and concentrated in vacuo to give a brown
resin, from which the pure title acetal was obtained by chromatography on silica gel
with toluene/acetone 95:5.
Yield: 25.9 g (81 %) of a yellow resin
Step C: Preparation of ethyl rac-(6-(N-tert.-butoxycarbonylamino)-3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (334):
[0228]

To a solution of 25.9 g (88.3 mmol) of the compound from Step B in 150 ml toluene
were added 32.4 g (93.0 mmol) of ethoxycarbonylmethylene triphenylphosphorane followed
by 0.6 g (15 mmol) 60 % sodium hydride in small portions. The mixture was heated at
120 °C for 3 hours, cooled to room temperature, and solids were removed by filtration.
The filtrate was concentrated under reduced pressure, and the compound (334) was obtained
by chromatography on silica gel with hexane / ethyl acetate 4:1 to 1:1.
Yield: 6.9 g (22 %) of colorless crystals,
m.p. 116-119°C.
Step D: Preparation of ethyl rac-(6-(N-(4-cyanobenzoyl)amino)-3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-2-yl)acetate,
an intermediate represented by the formula (335) :
[0229]

2.18 g (6.0 mmol) of the compound from the previous Step were deprotected by stirring
in 10 ml trifluoroacetic acid as described in Example 3, Step E, and the brown oil
of the crude 6-aminobenzopyran was dissolved in 40 ml dry pyridine. After addition
of 0.99 g (6.0 mmol) 4-cyanobenzoyl chloride the mixture was stirred at room temperature
overnight. It was concentrated to dryness in vacuo and dissolved three times in toluene
followed by concentration under reduced pressure, in order to remove remaining pyridine.
The title nitrile crystallized from the brown residue upon stirring with a small amount
of ethanol. It was filtered with suction, washed with cold ethanol, and dried in vacuo.
Yield: 1.7 g (72 %) of a white powder,
m.p. 163-165°C.
Step E: Preparation of ethyl rac-(5-(N-(4-(aminoiminomethyl)benzoyl)amino)-3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-2-yl)acetate
hydrochloride
[0230] A suspension of 1.7 g (4.33 mmol) of the nitrile from Step D in 100 ml dry ethanol
was cooled with ice and saturated with gaseous hydrogen chloride. After standing overnight
at room temperature it was concentrated to dryness under reduced pressure, and the
residue was dissolved in 50 ml 10 % ethanolic solution of ammonia. The mixture was
stirred at room temperature for three days until the reaction was complete. The solvent
was removed in vacuo, and the resinous residue was dissolved in toluene/acetone 7:3.
A first crop of the title amidine crystallized from the solution, and another crop
was obtained by chromatography on silica gel using the same mixture of solvents.
Total yield: 1.6 g (83 %) of a yellow crystalline solid, m.p. 122-124°C.
Example 34
Preparation of rac-(6-(N-(4-(Aminoiminomethyl)benzoyl)amino)-3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (336):
[0231]

0.3 g (0.67 mmol) of the ester from Example 33 were suspended in 10 ml ethanol followed
by addition of 1 ml aqueous 2 N sodium hydroxide. It was stirred at room temperature
for 4 hours. The mixture was filtered, the filtrate concentrated to dryness under
reduced pressure, and the residue was dissolved in water. It was then neutralized
with diluted acetic acid, and the precipitate of the compound (336) was filtered with
suction, washed thoroughly with water, and dried in vacuo at 50 °C.
Yield: 0.2 g (78 %) of a yellow crystalline solid,
m.p. 248-250°C.
Example 35
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(4-((propylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (337):
[0232]

To a solution of 0.8 g (1.8 mmol) of the crude intermediate of Example 13, Step A
in 20 ml ethanol were added at 0 °C 0.3 ml n-propylamine. The mixture was stirred
overnight at room temperature and concentrated under reduced pressure. The residue
was treated with ethanol and ether to give the pure crystalline title compound, which
was collected by filtration and dried in vacuo.
Yield: 0.63 g (76 %) of a white powder,
m.p. 271-273°C.
Example 36
Preparation of rac-(3,4-Dihydro-6-(N-(4-((propylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (338):
[0233]

0.25 g (0.54 mmol) of the ester from Example 35 were stirred at room temperature
overnight with 5 ml ethanol and 0.7 ml 2 N aqueous sodium hydroxide. The mixture was
brought to pH 4 with 2 N acetic acid, and the precipitate of the acid (338) was filtered
with suction, washed successively with water and with acetone, and dried in vacuo.
Yield: 0.16 g (74 %) of a pale yellow powder,
m.p. 241-242°C (dec.).
Example 37
Preparation of Ethyl rac-(6-(N-(4-((Butylamino)iminomethyl)benzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (339):
[0234]

The compound was prepared from 0.8 g (1.8 mmol) of the crude intermediate of Example
13, Step A and 0.3 ml n-butylamine as described in Example 35.
Yield: 0.6 g (71 %) of a pale yellow powder,
m.p. 265-267°C.
Example 38
Preparation of rac-(6-(N-(4-((Butylamino)iminomethyl)benzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (340):
[0235]

0.25 g (0.53 mmol) of the ester from Example 37 were hydrolyzed to the title acid
as described in Example 36. Yield: 0.13 g (60 %) of a white powder,
m.p. 240-241°C (dec.).
Example 39
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(4-((propoxycarbonylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate,
a compound represented by the formula (341):
[0236]

[0237] 417 mg (1.0 mmol) of the compound from Example 3, 0.3 ml triethylamine, 20 mg 4-dimethylaminopyridine,
and 135 mg (1.1 mmol) propyl chloroformate were dissolved in 20 ml dichloromethane
at 0 °C followed by stirring overnight at room temperature. After addition of the
same volume of water it was extracted with ethyl acetate. The organic layer was dried
over sodium sulfate and concentrated under reduced pressure to give the crude title
compound, which was recrystallized from dichloromethane/hexane.
Yield: 0.27 g (58 %) of a pale yellow amorphous solid, m.p. 183-184°C.
Example 40
Preparation of Propyl rac-(6-(N-(4-(Aminoiminomethyl)benzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (342) :
[0238]

A solution of 0.5 g (1.37 mmol) of the nitrile from Example 3, Step E in 50 ml n-propanol
was cooled with ice and saturated with gaseous hydrogen chloride. After stirring overnight
at room temperature the mixture was concentrated under reduced pressure, and the residue
was treated with 50 ml of a saturated solution of ammonia in n-propanol. Again the
mixture was stirred overnight at room temperature, the solvent removed in vacuo, and
the remaining title amidine was recrystallized from n-propanol.
Yield: 0.36 g (61 %) of a yellow powder,
m.p. 238-240°C (dec.).
Example 41
Preparation of Methyl rac-(6-(N-(4-(Aminoiminomethyl)benzoyl)amino)-3,4-dihydro-2H-1-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (343):
[0239]

A suspension of 0.35 g (1.0 mmol) of the acid from Example 4 in 20 ml methanol was
cooled to 0°C and saturated with gaseous hydrogen chloride. After 2 hours stirring
it was concentrated under reduced pressure, and the remaining compound (343) was recrystallized
from methanol/ether.
Yield: 0.29 g (72 %) of yellow crystals,
m.p. 235-237°C.
Example 42
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(2-fluoro-4-((methoxycarbonylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate,
a compound represented by the formula (349)
[0240]

436 mg (1.0 mmol) of the amidine from Example 23, 0.3 ml triethylamine, and 20 mg
4-dimethylaminopyridine were dissolved in 29 ml dichloromethane followed by addition
of 104 mg (1.1 mmol) methyl chloroformate at 0 °C. After stirring overnight at room
temperature a white precipitate of the title compound had been formed. It was filtered
with suction and washed successively with water and with ether.
Yield: 0.35 g (77%) of a pale yellow powder,
m.p. 202-204 °C
Example 43
Preparation of Ethyl rac- (3,4-Dihydro-6-(N-(4-((ethoxycarbonylamino)iminomethyl)-2-fluorobenzoyl)amino)-2H-1-benzopyran-2-yl)acetate,
a compound represented by the formula (350):
[0241]

The title carbamate was prepared as described in Example 42 from 436 mg (1.0 mmol)
of the amidine from Example 23 and 119 mg (1.1 mmol) ethyl chloroformate. It was recrystallized
from dichloromethane/hexane.
Yield: 0.35 g (74%) of a white powder,
m.p. 168-169 °C
Example 44
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(2-fluoro-4-((propoxycarbonylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate,
a compound represented by the formula (351):
[0242]

The title compound was prepared as described in Example 39 from 436 mg (1.0 mmol)
of the amidine from Example 23 and 135 mg (1.1 mmol) propyl chloroformate.
Yield: 0.29 g (60%) of a white crystalline solid,
m.p. 157-159 °C
Example 45
Proposed Method for Preparation of rac-4-Aminoiminomechyl-N-(3,4-dihydro-2-(1H-cetrazol-5-yl)methyl-2H-1-benzopyran-6-yl)benzamide,
a compound represented by the formula (352)
[0243]

Step A: Preparation of tert.-butyl rac-(2-cyanomethyl-3,4-dihydro-2H-1-benzopyran-6-yl)carbamate,
an intermediate represented by the formula (353):
[0244]

Step B: Preparation of tert.-butyl rac-(3,4-dihydro-2-(1H-tetrazol-5-yl)methyl-2H-1-benzopyran-6-yl)carbamate,
an intermediate represented by the formula (354) :
[0245]

Step C: Preparation of rac-4-cyano-N-(3,4-dihydro-2-(1H-tetrazol-5-yl)methyl-2H-1-benzopyran-6-yl)benzamide,
a compound represented by the formula (355):
[0246]

Example 46
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(4-(N'-(phenylmethylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (356)
[0247]

A mixture of 0.49 g (1.1 mmol) of the intermediate from Example 13 Step A and 0.5
ml benzylamine in 15 ml dry ethanol was stirred for 5 hours at room temperature. The
solvent was removed under reduced pressure, and the remaining title compound crystallized
from ethanol/ether. The crystals were collected by filtration, washed with ether,
and dried in vacuo.
Yield: 0.49 g (88%) of pale yellow crystals,
m.p. 254-256 °C
Example 47
Preparation of rac-(3,4-Dihydro-6-(N-(4-(N'-(phenylmethylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (357)
[0248]

0.2 g (0.39 mmol) of the ester from Example 46 were added to a mixture of 10 ml ethanol
and 0.5 ml 2 N aqueous sodium hydroxide solution. After gentle warming it was stirred
overnight at room temperature. The mixture was brought to pH 4 with 2 N acetic acid,
and the precipitate of the title acid was filtered with suction, washed successively
with water and with acetone, and dried in vacuo.
Yield: 0.12 g (69%) of a pale yellow powder,
m.p. 220 °C (dec.)
Example 48
Preparation of Ethyl rac-(3,4-Dihydro-6-(N-(4-((pentylamino)iminomethyl)benzoyl)amino)-2H-1-benzopyran-2-yl)acetate
hydrochloride, a compound represented by the formula (363) :
[0249]

To a suspension of 447 mg (1.0 mmol) of the intermediate from Example 13, Step A
in 15 ml dry ethanol were added at 0 °C 0.5 ml n-pentylamine. The mixture became a
clear solution upon stirring overnight at room temperature. It was concentrated under
reduced pressure, and the crystalline residue of the title compound was recrystallized
from ethanol/ether.
Yield: 0.33 g (68%) of pale yellow crystals,
m.p. 267-269°C.
Example 49
Preparation of rac-(3,4-Dihydro-6-(N-(4-((pentylamino)iminomethyl)benzoyl)amino) -2H-1-benzopyran-2-yl)acetic
Acid, a compound represented by the formula (364):
[0250]

0.15 g (0.31 mmol) of the ester from Example 48 were stirred overnight at room temperature
in a mixture of 10 ml ethanol and 0.7 ml 2 N aqueous sodium hydroxide solution. It
was brought to pH 4 with 2 N acetic acid, and the precipitate of the title acid was
filtered, washed successively with water and with acetone, and dried in vacuo.
Yield: 98 mg (75%) of colorless crystals,
m.p. 223-225 °C (dec.).
[0251] Reference numbers in the following Examples are found in Reaction Schemes 27 to 33,
supra.
Assay Methods:
[0252] The identification of compounds which are active platelet aggregation inhibitors
(PAI) is made possible by the observation that compounds which block the binding of
fibrinogen to the GPIIb-IIIa complex in vitro also are capable of inhibiting thrombin
or ADP-induced aggregation of human platelets and the formation of platelet-thrombi
in vivo. This observation provides the basis for obtaining potent PAI's by evaluating
the ability of test materials to disrupt fibrinogen-GPIIb-IIIa interactions.
[0253] The following assay methods were used to evaluate the compounds of the invention,
inclusive of the compounds represented by formulae (I), (II), (Ix), (Xd) and (Xe)
as previously described.
No. 1 - The ELISA IIb-IIIa Assay:
[0254] In the following assay, GPIIb-IIIa is prepared in purified form, by a method such
as described by Fitzgerald, L.A., et al.,
Anal Biochem (1985)
151:169-177, (the disclosure of which is incorporated herein by reference). GPIIb-IIIa
is coated onto microtiter plates. The coated support is then contacted with fibrinogen
and with the test material (e.g., compounds of Formula I) and incubated for a sufficient
time to permit maximal binding of fibrinogen to the immobilized GPIIb-IIIa. Fibrinogen
is typically provided at a concentration of about 5-50 nM and the test material can,
if desired, be added at a series of dilution. Typical incubations are 2 to 4 hours
at 25 °C, the time and temperature being interdependent.
[0255] After incubation, the solution containing the fibrinogen and test material is removed
and the level of binding of fibrinogen measured by quantitating bound fibrinogen to
GPIIb-IIIa. Any suitable means of detection may be used, but it is convenient to employ
labeled fibrinogen, for example using biotinylated labels. Such methods are well known
in the art.
A. Description of Assays--Plate Assays
[0256] Purified platelet GPIIb-IIIa receptor was prepared as described by Fitzgerald, L.A.,
et al.,
Anal Biochem (1985)
151:169-177 (1985). Vitronectin receptor was prepared as described by Smith, J.W.,
J. Biol Chem (1988)
263:18726-18731. After purification, the receptors were stored in 0.1% Triton X-100 at
0.1-1.0 mg/ml.
[0257] The receptors were coated to the wells of 96-well flat-bottom ELISA plates (Linbro
EIA-Plus microtiter plate, Flow Laboratories) after diluting 1:200 with a solution
of 20 mM Tris-HCl, 150 mM NaCl, 1 mM CaCl
2, pH 7.4, to reduce the Triton X-100 concentration to below its critical micellar
concentration and adding an aliquot of 100 ul to each well. The wells were all allowed
to incubate overnight at 4 °C, and then aspirated to dryness. Additional sites were
blocked by the addition of bovine serum albumin (BSA) at 35 mg/ml in the above buffer
for 2 hours at 30 °C to prevent nonspecific binding. The wells were then washed once
with binding buffer (50 nM Tris-HCl, 100 mM NaCl 2 mM CaCl
2, 1 mg/ml BSA).
[0258] The corresponding ligands (fibrinogen, von Willebrand Factor, or vitronectin) were
conjugated to biotin using commercially available reagents and standard protocols.
The labeled ligands were added to the receptor-coated wells at final concentration
of 10 nM (100 ul/well) and incubated for 3 hours at 25 °C in the presence or absence
of the test samples. After incubation, the wells are aspirated to dryness and bound
ligand is quantitated.
[0259] The bound protein is detected by the addition of antibiotin antibody conjugated to
alkaline phosphatase followed by addition of substrate (p-nitrophenyl phosphate),
and determination of the optical density of each well at 405 nM. Decreased color development
is observed in wells incubated with test samples which inhibit binding of ligand to
receptor.
No. 2 - The Platelet Aggregation Assay
[0260] In addition to the ELISA IIb-IIIa assay previously described the Aggregation-Human
PRP/ADP Assay is useful for evaluating therapeutic compounds.
[0261] Platelet-rich plasma was prepared from healthy human volunteers for use in determining
inhibition of platelet aggregation by the compounds. Blood was collected via a 21
gauge butterfly cannula, using a two-syringe technique into 1/10 volume of 3.8% trisodium
citrate.
[0262] Platelet-rich plasma was prepared at room temperature by centrifugation of the citrated
whole blood at 100 x g for 12 minutes. The platelet rich plasma contained approximately
200-400,000 platelets/µl.
[0263] Platelet-poor plasma was prepared by centrifugation of citrated whole blood at 12,000
x g for 2 minutes.
[0264] Platelet aggregation was assayed in a 4-channel platelet aggregation profiler (PAP-4,
Biodata, Hatboro, PA) according to the manufacturers directions. Inhibition of platelet
aggregation was studied by adding varying amounts of adenosine diphosphate (ADP) to
stirred human platelet-rich plasma. Specifically, the human platelet-rich plasma was
incubated with the compound being tested for 1 minute at 37 °C prior to the addition
of a variety of aggregating agents most often ADP 5 µM, but also 1 µg/ml collagen,
1 µM U46619 and 0.3 µM platelet activating factor.
| Table of Assay Test Results |
| Example No. |
ELISA IIB/IIIa |
Agg: Human PRP/ADP |
| |
IC50 µM |
IC50µm |
| 1 |
NT |
11 |
| 2 |
0.0033 |
2.5 |
| 3 |
0.77 |
0.24 |
| 4 |
0.004 |
0.066 |
| 5 |
NT |
100 |
| 6 |
3.93 |
100 |
| 7 |
1.16 |
40 |
| 8 |
NT |
100 |
| 9 |
0.72 |
21 |
| 10 |
NT |
12 |
| 11 |
3.46 |
>100 |
| 12 |
0.14 |
0.9 |
| 13 |
>10 |
0.66 |
| 14 |
0.0334 |
0.28 |
| 15 |
>10 |
21 |
| 16 |
1.8 |
>10 |
| 17 |
>1 |
100 |
| 18 |
0.80 |
11 |
| 19 |
0.18 |
4.8 |
| 20 |
NT |
>100 |
| 21 |
NT |
29 |
| 22 |
>1 |
NT |
| 23 |
0.009 |
0.16 |
| 24 |
0.0013 |
0.082 |
| 25 |
>10 |
1.5 |
| 26 |
0.0185 |
0.28 |
| 27 |
>10 |
1.2 |
| 28 |
NT |
NT |
| 29 |
NT |
1.8 |
| 30 |
0.014 |
0.56 |
| 31 |
NT |
1.3 |
| 32 |
0.02 |
0.18 |
| 33 |
NT |
>100 |
| 34 |
1 |
>100 |
| 35 |
NT |
0.39 |
| 36 |
0.019 |
0.12 |
| 37 |
NT |
0.14 |
| 38 |
0.0055 |
0.084 |
| 39 |
NT |
>100 |
| 40 |
NT |
0.078 |
| 41 |
NT |
0.084 |
| 42 |
0.099 |
0.084 |
| 43 |
NT |
NT |
| 44 |
NT |
NT |
| 45 |
NT |
NT |
| 46 |
NT |
0.24 |
| 47 |
0.0094 |
0.086 |
| 48 |
NT |
NT |
| 49 |
NT |
NT |
| Note: NT = not tested |
Pharmaceutical Compositions
[0265] Pharmaceutical formulations containing compounds of the invention can be administered
orally in the form of tablets, capsules, solutions, emulsions or suspensions, inhaled
liquid or solid particles, as a spray, through the skin by an appliance such a transdermal
patch (such as described in US Patents No. 5,296,222 and 5,271,940, the disclosures
of which are incorporated herein by reference) or rectally, for example, in the form
of suppositories. The. lipophilic prodrug derivatives of the invention (e.g., formula
Xd, Xe) are particularly well suited for transdermal absorption administration and
delivery systems. Administration can also take place parenterally, for example in
the form of injectable solutions.
[0266] Tablets are prepared by mixing the Active
[0267] Ingredient ("Active Ingredient" is one or more compounds of the invention inclusive
of those corresponding to formulae I, II, Xd, or Xe) with pharmaceutically inert,
inorganic or organic carriers, diluents, and/or excipients. Examples of such excipients
which can be used for tablets, are lactose, maize starch or derivatives thereof, talc,
stearic acid or salts thereof. Examples of suitable excipients for soft gelatin capsules
are vegetable oils, waxes, fats, semisolid and liquid polyols.
[0268] Suitable excipients for the preparation of solutions and syrups are water, polyols,
sucrose, invert sugar and glucose.
[0269] Suitable excipients for injectable solutions are water, alcohols, polyols, glycerol
and vegetable oils.
[0270] These pharmaceutical products can additionally contain preservatives, solubilizers,
stabilizers, wetting agents, emulsifiers, sweeteners, colorants, flavorings, buffers,
coating agents and antioxidants.
[0271] Pharmaceutical compositions of this invention for parenteral injection comprise pharmaceutically
acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions
as well as sterile powders for reconstitution into sterile injectable solutions or
dispersions just prior to use.
[0272] The Active Ingredient can also be made in micro-encapsulated form.
[0273] Exemplary formulations using the Active Ingredient are described below:
Formulation 1
[0274] Hard gelatin capsules are prepared using the following ingredients:
| |
(mg/capsule) |
| Active Ingredient |
250.0 |
| Starch |
305.0 |
| Magnesium stearate |
5.0 |
[0275] The above ingredients are mixed and filled into hard gelatin capsules in 560 mg quantities.
Formulation 2
[0276] A tablet formula is prepared using the ingredients below:
| |
(mg/tablet) |
| Active Ingredient |
250.0 |
| Cellulose, microcrystalline |
400.0 |
| Colloidal silicon dioxide |
10.0 |
| Stearic acid |
5.0 |
[0277] The components are blended and compressed to form tablets, each weighing 665 mg.
Formulation 3
[0278] A dry powder inhaler formulation is prepared containing the following components:
| |
Weight % |
| Active ingredient |
5 |
| Lactose |
95 |
[0279] The active mixture is mixed with the lactose and the mixture is added to a dry powder
inhaling appliance.
Formulation 4
[0280] Tablets, each containing 60 mg of active ingredient, are prepared as follows:
| |
(milligrams) |
| Active ingredient |
60.0 |
| Starch |
45.0 |
| Microcrystalline cellulose |
35.0 |
| Polyvinylpyrrolidone |
|
| (as 10% solution in water) |
4.0 |
| Sodium carboxymethyl starch |
4.5 |
| Magnesium stearate |
0.5 |
| Talc |
1.0 |
| Total |
150.0 |
[0281] The active ingredient, starch and cellulose are passed through a No. 20 mesh U.S.
sieve and mixed thoroughly. The solution of polyvinylpyrrolidone is mixed with the
resultant powders, which are then passed through a 16 mesh U.S. sieve. The granules
as produced are dried at 50-60°C and passed through a 16 mesh U.S. sieve. The sodium
carboxymethyl starch, magnesium stearate, and talc, previously passed through a No.
30 mesh U.S. sieve, are then added to the granules which, after mixing, are compressed
on a tablet machine to yield tablets each weighing 150mg.
Formulation 5
[0282] Capsules, each containing 80 mg of medicament are made as follows:
| |
(milligrams) |
| Active ingredient |
80.0 |
| Starch |
109.0 |
| Magnesium stearate |
1.0 |
| Total |
190.0 |
[0283] The active ingredient, cellulose, starch, and magnesium stearate are blended passed
through a No. 20 mesh U.S. sieve, and filled into hard gelatin capsules in 190 mg
quantities.
Formulation 6
[0284] Suppositories, each containing 225 mg of active ingredient are made as follows:
| Active Ingredient |
225 mg |
| Saturated fatty acid glycerides to |
2000 mg |
[0285] The active ingredient is passed through a No. 60 mesh U.S. sieve and suspended in
the saturated fatty acid glycerides previously melted using the minimum heat necessary.
The mixture is then poured into a suppository mold of nominal 2.0 g capacity and allowed
to cool.
Formulation 7
[0286] Suspensions, each containing 50 mg of medicament per 5.0 mL dose are made as follows:
| Active ingredient |
50.0 mg |
| Xanthan gum |
4.0 mg |
| Sodium carboxymethyl cellulose |
(11%) |
| Microcrystalline cellulose |
(89%) 50.0 mg |
| Sucrose |
1.75 g |
| Sodium benzoate |
10.0 mg |
| Flavor |
q.v. |
| Color |
q.v. |
| Purified water to |
5.0mL |
[0287] The medicament, sucrose and xanthan gum are blended, passed through a No. 10 mesh
U.S. sieve, and then mixed with a previously made solution of the microcrystalline
cellulose and sodium carboxymethyl cellulose in water. The sodium benzoate, flavor,
and color are diluted with some of the water and added with stirring. Sufficient water
is then added to produce the required volume.
Formulation 8
[0288] Capsules, each containing 150 mg of medicament, are made as follows:
| |
(milligrams) |
| Active ingredient |
150.0 |
| Starch |
407.0 |
| Magnesium stearate |
3.0 |
| Total |
560.0 |
[0289] The active ingredient, cellulose, starch, and magnesium stearate are blended, passed
through a No. 20 mesh U.S. sieve, and filled into hard gelatin capsules in 560 mg
quantities.
Method of Treatment
[0290] This invention provides a method of preventing or treating thrombosis in mammals,
especially humans, which method comprises administering to the human or mammal a therapeutically
effective amount of the compounds of this invention. The platelet aggregation inhibitors
of the invention are useful therapeutically to prevent thrombus formation. Indications
appropriate to such treatment include, without limitation, atherosclerosis and arteriosclerosis,
acute myocardial infarction, chronic unstable angina, transient ischemic attacks and
strokes, peripheral vascular disease, arterial thrombosis, preeclampsia, embolism,
restenosis and/or thrombosis following angioplasty, carotid endarterectomy, anastomosis
of vascular grafts, and chronic cardiovascular devices (e.g., in-dwelling catheters
or shunts "extracorporeal circulating devices"). These syndromes represent a variety
of stenotic and occlusive vascular disorders thought to be initiated by platelet activation
on vessel walls.
[0291] The PAIs may be used for prevention or abortion of arterial thrombus formation, in
unstable angina and arterial emboli or thrombosis, as well as treatment or prevention
of myocardial infarction (MI) and mural thrombus formation post MI. For brain-related
disorders, treatment or prevention of transient ischemic attack and treatment of thrombotic
stroke or stroke-in-evolution are included.
[0292] The PAIs may also be used for prevention of platelet aggregation, embolization, or
consumption in extracorporeal circulations, including improving renal dialysis, cardiopulmonary
bypasses, hemoperfusions, and plasmapheresis.
[0293] PAIs prevent platelet aggregation, embolization, or consumption associated with intravascular
devices, and administration results in improved utility of intraaortic balloon pumps,
ventricular assist devices, and arterial catheters.
[0294] The PAIs will also be useful in treatment or prevention of venous thrombosis as in
deep venous thrombosis, IVC, renal vein or portal vein thrombosis, and pulmonary venous
thrombosis.
[0295] Various disorders involving platelet consumption, such as thrombotic thrombocytopenic
purpura are also treatable.
[0296] In addition, the PAIs of the present invention may be used in numerous nontherapeutic
applications where inhibiting platelet aggregation is desired. For example, improved
platelet and whole blood storage can be obtained by adding sufficient quantities of
the compounds, the amount of which will vary depending upon the length of proposed
storage time, the conditions of storage, the ultimate use of the stored material,
etc.
[0297] Preferably, the compounds of this invention are administered in the form of a pharmaceutical
formulation. Thus, the compounds of this invention may be administered orally, parenterally,
topically, rectally and etc., in, appropriate dosage units, as desired.
[0298] The term parenteral as used herein includes subcutaneous, intravenous, intraarterial,
injection or infusion techniques, without limitation. The term, "topically" encompasses
administration rectally and by inhalation spray, as well as the more common routes
of the skin and the mucous membranes of the mouth and nose.
[0299] Actual dosage levels of active ingredients in the pharmaceutical compositions of
this invention may be varied so as to administer an amount of the active compound(s)
that is effective to achieve the desired therapeutic response for a particular patient.
[0300] The selected dosage level will depend upon the activity of the particular compound,
the route of administration, the severity of the condition being treated, and the
condition and prior medical history of the patient being treated. However, it is within
the skill of the art to start doses of the compound at levels lower than required
to achieve the desired therapeutic effect and to gradually increase the dosage until
the desired effect is achieved. If desired, the effective daily dose may be divided
into multiple doses for purposes of administration, e.g., two to four separate doses
per day. It will be understood, however, that the specific dose level for any particular
patient will depend upon a variety of factors including the body weight, general health,
diet, time and route of administration, combination with other drugs and the severity
of the particular disease being treated.
[0301] The range of therapeutic dosages is from about 0.01 to about 10,000 milligrams per
day, with from 1 to 300 milligrams being preferred.
[0302] Many modifications and variations of this invention may be made without departing
from its scope, as is apparent to those skilled in the art. The specific embodiments
described herein are offered by way of example only, and the invention is to be limited
only by the terms of the appended claims.