[0001] The present invention relates to novel antidiabetic compounds, their tautomeric forms,
their derivatives, their stereoisomers, their polymorphs, their pharmaceutically acceptable
salts, their pharmaceutically acceptable solvates and pharmaceutically acceptable
compositions containing them. This invention particularly relates to novel azolidinedione
derivatives of the general formula (I), their tautomeric forms, their stereoisomers,
their polymorphs and their pharmaceutically acceptable salts, pharmaceutically acceptable
solvates and pharmaceutical compositions containing them.

[0002] The present invention also relates to a process for the preparation of the above
said novel, azolidinedione derivatives, their tautomeric forms, their stereoisomers,
their polymorphs, their pharmaceutically acceptable salts, pharma-ceutically acceptable
solvates, novel intermediates and pharmaceutical compositions containing them.
[0003] The azolidinedione derivatives of the general formula (I) defined above of the present
invention are useful for the treatment and / or prophylaxis of diseases or conditions
in which insulin resistance is the underlying pathophysiological mechanism. Examples
of these diseases and conditions are type II diabetes, impaired glucose tolerance,
dyslipidaemia, hypertension, coronary heart disease and other cardiovascular disorders
including atherosclerosis. The azolidinedione derivatives of the formula (I) are useful
for the treatment of insulin resistance associated with obesity and psoriasis. The
azolidinedione derivatives of the formula (I) can also be used to treat diabetic complications
and can be used for treatment and / or prophylaxis of other diseases and conditions
such as polycystic ovarian syndrome (PCOS), certain renal diseases including diabetic
nephropathy, glomerulonephritis, glomerular sclerosis, nephrotic syndrome, hypertensive
nephrosclerosis, end-stage renal diseases and microalbuminuria as well as certain
eating disorders, as aldose reductase inhibitors and for improving cognitive functions
in dementia.
BACKGROUND OF THE INVENTION
[0004] Insulin resistance is the diminished ability of insulin to exert its biological action
across a broad range of concentrations. In insulin resistance, the body secretes abnormally
high amounts of insulin to compensate for this defect; failing which, the plasma glucose
concentration inevitably rises and develops into diabetes. Among the developed countries,
diabetes mellitus is a common problem and is associated with a variety of abnormalities
including obesity, hypertension, hyperlipidemia (J. Clin. Invest., (1985) 75: 809-817;
N. Engl. J. Med. (1987) 317: 350-357; J. Clin. Endocrinol. Metab., (1988) 66: 580-583;
J. Clin. Invest., (1975) 68: 957-969) and other renal complications (See Patent Application
No. WO 95/21608). It is now increasingly being recognized that insulin resistance
and relative hyperinsulinemia have a contributory role in obesity, hypertension, atherosclerosis
and type 2 diabetes mellitus. The association of insulin resistance with obesity,
hypertension and angina has been described as a syndrome having insulin resistance
as the central pathogenic link-Syndrome-X. In addition, polycystic ovarian syndrome
(Patent Application No. WO 95/07697), psoriasis (Patent Application No. WO 95/35108),
dementia (Behavioral Brain Research (1996) 75: 1-11) etc. may also have insulin resistance
as a central pathogenic feature.
[0005] A number of molecular defects have been associated with insulin resistance. These
include reduced expression of insulin receptors on the plasma membrane of insulin
responsive cells and alterations in the signal transduction pathways that become activated
after insulin binds to its receptor including glucose transport and glycogen synthesis.
[0006] Since defective insulin action is thought to be more important than failure of insulin
secretion in the development of non-insulin dependent diabetes mellitus and other
related complications, this raises doubts about the intrinsic suitability of antidiabetic
treatment that is based entirely upon stimulation of insulin release. Recently, Takeda
has developed a new class of compounds which are the derivatives of 5-(4-alkoxybenzyl)-2,4-thiazolidinediones
of the formula (II) (Ref.
Chem. Pharm. Bull. 1982, 30, 3580-3600). In the formula (II), V represents substituted or unsubstituted
divalent aromatic group and U represents various groups which have been reported in
various patent documents.

[0007] By way of examples, U may represent the following groups:
(i) a group of the formula (IIa) where R1 is hydrogen or hydrocarbon residue or heterocyclic residue which may each be substituted,
R2 is hydrogen or a lower alkyl which may be substituted by hydroxy group, X is an oxygen
or sulphur atom, Z is a hydroxylated methylene or a carbonyl, m is 0 or 1, n is an
integer of 1-3. These compounds have been disclosed in the European Patent Application
No. 0 177 353

An example of these compounds is shown in formula (IIb)

(ii) a group of the formula (IIc) wherein R1 and R2 are the same or different and each represents hydrogen or C1-C5 alkyl, R3 represents hydrogen, acyl group, a (C1-C6) alkoxycarbonyl group or aralkyloxycarbonyl group, R4- R5 are same or different and each represent hydrogen, C1-C5 alkyl or C1-C5 alkoxy or R4, R5 together represent C1-C4 alkenedioxy group, n is 1, 2, or 3, W represents CH2, CO, CHOR6 group in which R6 represents any one of the items or groups defined for R3 and may be the same or different from R3. These compounds are disclosed in the European Patent Application No. 0 139 421.

An example of these compounds is shown in (lid)

iii) A group of formula (lie) where A1 represents substituted or unsubstituted aromatic heterocyclic group, R1 represents a hydrogen atom, alkyl group, acyl group, an aralkyl group wherein the
aryl moiety may be substituted or unsubstituted, or a substituted or unsubstituted
aryl group, n represents an integer in the range from 2 to 6. These compounds are
disclosed in European Patent No. 0 306 228.

An example of this compound is shown in formula (llf)

iv) A group of formula (IIg) where Y represents N or CR5, R1, R2, R3, R4 and R5 represents hydrogen, halogen, alkyl and the like and R6 represents hydrogen, alkyl, aryl and the like, n represents an integer of 0 to 3.
These compounds are disclosed in European Patent Application No. 0 604 983.

An example of this compound is shown in formula (IIh)

v) A group of formula (IIi a-d) where R1 represents hydrogen atom, halogen, linear or branched (C1-C6)alkyl, (C1-C6)alkoxy, trifluoromethyl or cyano groups and X represents S, O or NR where R = H or
(C1-C6)alkyl group. These compounds are disclosed in European Patent Application No. 0 528
734.


An example of this class of compound is shown in formula (IIj)

Still another class of antihyperglycemic agents are 5-substituted oxazolidine-2,4-diones
and 2-substituted-1,2,4-oxadiazolidine-3,5-diones which can be represented in the
formula (IIk),

where V represents substituted or unsubstituted divalent aryl or hetero aryl group,
W represents various groups which have been reported in various patent documents,
A represents nitrogen atom or a CH group and B is an oxygen atom.
By way of examples, W may represent the following groups:
vi) a group of formula (II 1), where R is (C1-C6) alkyl groups, cycloalkyl group, furyl, thienyl, substituted or unsubstituted phenyl
group, X is hydrogen, methyl, methoxy, chloro or fluoro.
These compounds have been disclosed in the U.S. Patent No. 5 037 842.

An example of these compounds is shown in formula (IIm).

(vii) A group of formula (IIn) wherein A1 represents a substituted or unsubstituted aromatic heterocyclyl group; R1 represents a hydrogen atom, an alkyl group, an acyl group, an aralkyl group, wherein
the aryl moiety may be substituted or unsubstituted or a substituted or unsubstituted
aryl group, n represents an integer in the range of from 2 to 6. These compounds have
been disclosed in the patent application No. WO 92/02520.

An example of these compounds is shown in formula (IIo)

(viii) A group of formulae (IIp) and (IIq), where R1 is hydrogen, (C1-C8)alkyl, (C1-C8)alkoxy, trifluoroalkoxy, halogen or trifluoromethyl group, R2 is hydrogen or methyl and X is oxygen or sulfur. These compounds have been described
in U.S. Patent No. 5 480 486.

An example of these compounds is shown in formula (IIr)

(ix) a group of formula (IIs)

wherein:
X represents an indolyl, indolinyl, azaindolyl, azaindolinyl, imidazopyridyl or imidazopyrimidinyl
group which is unsubstituted or is substituted;
Y represents an oxygen atom or a sulphur atom;
Z represents a group of formula (i), (ii), (iii), (iv) or (v):


R represents a hydrogen atom, an alkyl group having from 1 to 4 carbon atoms, an alkoxy
group having from 1 to 4 carbon atoms, a halogen atom, a hydroxy group, a nitro group,
an aralkyl group in which an alkyl group having from 1 to 5 carbon atoms is substituted
by an aryl group having from 6 to 10 ring carbon atoms, or a group of formula -NRaRb,
wherein R
a and R
b are the same or different and each represents a hydrogen atom, an alkyl group having
from 1 to 8 carbon atoms, an aralkyl group in which an alkyl group having from 1 to
5 carbon atoms is substituted by an aryl group having from 6 to 10 ring carbon atoms,
an aryl group having from 6 to 10 ring carbon atoms, an aliphatic carboxylic acyl
group having from 1 to 11 carbon atoms, an aliphatic carboxylic acyl group which has
from 2 to 6 carbon atoms and which is substituted by an aryl group having from 6 to
10 rings.carbon atoms, or an aromatic carboxylic acyl group in which the aryl part
has from 6 to 10 ring carbon atoms, m is an integer of from 1 to 5.
These compounds have been described in EP O 676 398A2.
(x) a group of formula (IIt)

in which:
X represents a benzimidazole group which is unsubstituted or is substituted;
Y represents an oxygen atom or a sulphur atom;
Z represents a group of formula (i), (ii), (iii), (iv) or (v):


R represents:
a hydrogen atom;
an alkyl group having from 1 to 4 carbon atoms;
an alkoxy group having from 1 to 4 carbon atoms;
a halogen atom;
a hydroxy group;
a nitro group;
a group of formula -NRaRb,
in which R
a and R
b are the same or different and each represents a hydrogen atom, an alkyl group having
from 1 to 8 carbon atoms, an aralkyl group in which an alkyl group having from 1 to
5 carbon atoms is substituted by a carbocyclic aryl group having from 6 to 10 carbon
atoms: a carbocyclic aryl group having from 6 to 10 carbon atoms: an aliphatic acyl
group having from 1 to 11 carbon atoms: an arylaliphatic acyl group in which an aliphatic
acyl group having from 2 to 6 carbon atoms is substituted by at least one carbocyclic
aryl group having from 6 to 10 carbon atoms: or an aromatic acyl group having from
7 to 11 carbon atoms: or an aralkyl group in which an alkyl group having from 1 to
5 carbon atoms is substituted by a carbocyclic aryl group having from 6 to 10 carbon
atoms; and m represents an integer from 1 to 5.
These compounds have been described in EP O 745 600A1.
(xi) a group of formula (IIu)

wherein R
1, R
2 and R
3 may be the same or different and individually represent a hydrogen atom, a halogen
atom, a lower alkyl group or lower alkoxyl group which may be substituted by one or
more halogen atom(s), a hydroxyl group, a nitro group, an amino group, a lower acylamino
group, a mono- or di-lower alkylamino group, a carboxyl group, a lower alkoxycarbonyl
group, a cyano group, a 2-oxazolyl group, a thiazolidine-2,4-dion-5-ylidene-methyl
group or a thiazolidine-2,4-dion-5-ylmethyl group and R
1 and R
2 may be coupled together to form an alkylene chain -(CH
2)
p- wherein p stands for 3, 4 or 5 or an alkylenedioxy chain -O-(CH
2)
qO- wherein q stands for 1, 2 or 3, thereby forming a ring; R
4 and R
5 may be the same or different and individually represent a hydrogen atom or a lower
alkyl group; X represents a carbon atom or nitrogen atom; Y represents an oxygen atom
or an imino group; A and B individually represent a lower alkylene group; m stands
for 0 or 1; and the dashed line indicates the presence or absence of a double bond;
or a salt thereof.
[0008] These compounds have been described in EP O 645 387A1.
SUMMARY OF THE INVENTION
[0009] With an objective of developing new compounds for the treatment of type II diabetes
[non-insulin-dependent-diabetes mellitus (NIDDM)] which could be more potent at relatively
lower doses and having better efficacy with lower toxicity, we focused our research
efforts in a direction of incorporating safety and to have better efficacy, which
has resulted in the development of novel azolidinedione derivatives having the general
formula (I) as defined above.
[0010] The main objective of the present invention is therefore, to provide novel azolidinedione
derivatives, their tautomeric forms, their stereoisomers, their polymorphs, their
pharmaceutically, acceptable salts, their pharmaceutically acceptable solvates and
pharmaceutical compositions containing them, or their mixtures.
[0011] Another objective of the present invention is to provide novel azolidinedione derivatives,
their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically
acceptable salts, their pharmaceutically acceptable solvates and pharmaceutical compositions
containing them or their mixtures having enhanced activities, no toxic effect or reduced
toxic effect.
[0012] Yet another objective of the present invention is to produce a process for the preparation
of novel azolidinediones of the formula (I) as defined above, their tautomeric forms,
their stereoisomers, their polymorphs, their pharmaceutically acceptable salts and
their pharmaceutically acceptable solvates.
[0013] Still another objective of the present invention is to provide pharmaceutical compositions
containing compounds of the general formula (I), their tautomers, their stereoisomers,
their polymorphs, their salts, solvates or their mixtures in combination with suitable
carriers, solvents, diluents and other media normally employed in preparing such compositions.
[0014] Yet another objective of the present invention is to provide a process for the preparation
of the novel intermediate of the formula (III)

where G represents -CHO, -NO
2; -NH
2, -CH=NHOH, -CH
2NHOH, -CH
2N(OH)CONH
2 or -CH
2CH(J)-COOR, where J represents hydroxy group, or halogen atom such as chlorine, bromine
or iodine and R represents H or lower alkyl group such as methyl, ethyl or propyl.
A, B, D, X, k, p and Ar are as defined in formula (I).
DETAILED DESCRIPTION OF THE INVENTION
[0015] Azolidinedione derivatives of the present invention have the general formula (I)

[0016] In the above formula (I), A represents dihydrobenzofuranyl, benzofuranyl , dihydrobenzopyranyl,
or indolyl, wherein the group represented by A may be substituted by hydroxy, (C
1-C
6)alkyl or (C
1-C
6)alkoxy, which alkoxy group may be itself substituted by aryl; B represents a linking
group and contains 1-4 carbon atoms, bonds; D represents a bond or D contains 1-4
carbons atoms, X represents either a CH
2 group, NH or sulfur; Ar represents phenylene, or naphthylene, R
1 represents hydrogen atom, carbon atoms or forms a bond together with the adjacent
group Y. Y represents a nitrogen atom or a group CR
2 where or alkyl R
2 forms a bond together with R
1; Z represents an oxygen atom or a sulfur atom when Y is CR
2 and Z represents an oxygen atom when Y is a nitrogen atom; k is an integer ranging
from 1-4-and p is an integer ranging from 0 to 1 When p is 0 (zero) (CH
2)
P represents a bond.
[0017] Suitable linking group between N and X represented by B may contain 1-4 carbon atoms,
1-2 being preferred and suitable linking group between N and X represented by D may
represent either a bond or contain 1-4 carbon atoms, 1-2 being preferred. The compounds
according to formula (I) always have a linking group B and a linking group D. The
linking group D having no carbon atom means that the linking group D represents a
bond.
[0018] Suitable X includes CH
2, NH or S, preferably CH
2, or NH. Preferred ring structures comprise a nitrogen atom, linking groups represented
by B and D, and X are pyrrolidinyl, piperidinyl, piperazinyl, aziridinyl and morpholinyl
groups.
[0019] It is more preferred that the ring structure comprise a nitrogen atom, linking groups
represented by B and D, and X and is a pyrrolidinyl group.
[0020] It is preferred that R
1 and R
2 represent hydrogen atom or R
1 and R
2 together represent a bond.
[0021] Suitable Z group includes a hetero atom selected from 0 or S, with the provision
that when Y is CR
2, Z is selected from sulfur or oxygen, and when Y is nitrogen, Z represents oxygen.
[0022] Suitable ring structure comprising Y and Z include 2,4-dioxooxazolidin-5-yl; 2,4-dioxothiazolidin-5-yl;
and 3,5-dioxo-1,2,4-oxadiazolidin-2-yl groups.
Preferred ring structures comprising Y and Z include 2,4-dioxooxazolidin-5-yl and
2,4-dioxothiazolidin-5-yl groups.
[0023] It is more preferred that the ring structure comprising Y and Z is a 2,4-dioxothiazolidin-5-yl
group.
[0024] Suitable k is an integer ranging from 1 to 4, especially 1 to 2 and suitable p is
an integer ranging from 0 to 4. It is preferred that p is 1 or 0. When p is zero (CH
2)p represents a bond; the ring structure comprising N, X and the linking groups B
and D is directly linked to the oxygen atom.
[0025] Pharmaceutically acceptable salts forming part of this invention include salts of
the azolidinedione moiety such as alkali metal salts like Li, Na, and K salts, alkaline
earth metal salts like Ca and Mg salts, salts of organic bases such as lysine, arginine,
guanidine, diethanolamine, choline and the like, ammonium or substituted ammonium
salts, salts of carboxy group wherever appropriate, such as aluminum, alkali metal
salts, alkaline earth metal salts, ammonium or substituted ammonium salts. Salts may
include acid addition salts which are, sulphates, nitrates, phosphates, perchlorates,
borates, hydrohalides, acetates, tartrates, maleates, citrates, succinates, palmoates,
methanesulphonates, benzoates, salicylates, hydroxynaphthoates, benzenesulfonates,
ascorbates, glycerophosphates, ketoglutarates and the like. Pharmaceutically acceptable
solvates may be hydrates or comprise other solvents of crystallization such as alcohols.
[0026] Particularly useful compounds according to the invention include:
5-[4-[N-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2S)-pyrrolidine-2-methoxyl]phenyl
methylene] thiazolidine-2,4-dione and its salts;
5-[4-[N-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2R)-pyrrolidine-2-methoxyl]phenyl
methylene] thiazolidine-2,4-dione, and its salts;
5-[4-[N-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione;
5-[4-[N-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2R)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione and its salts;
5-[4-[N-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione sodium salt;
5-[4-[N-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione maleic acid salt;
5-[4-[N-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione hydrochloride salt;
5-[4-[N-(6-hydroxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione;
5-[4-[N-(6-hydroxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2R)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione and its salts;
5-[4-[N-(6-hydroxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione sodium salt;
5-[4-[N-[6-hydroxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione maleic acid salt;
5-[4-[N-[6-hydroxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione hydrochloride salt;
5-[4-[N-[6-hydroxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione;
5-[4-[N-[6-hydroxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2R)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione and its salts;
5-[4-[N-[2,3-dihydro-5-benzyloxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione;
5-[4-[N-[2,3 -dihydro-5-benzyloxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2R)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione and its salts;
5-[4-[N-[2,3-dihydro-5-benzyloxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione maleic acid salt;
5-[4-[N-[2,3-dihydro-5-benzyloxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione hydrochloride salt;
5-[4-[N-[2,3-dihydro-5-benzyloxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]
phenyl methyl]thiazolidine-2,4-dione;
5-[4-[N-[2,3-dihydro-5-benzyloxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2R)-pyrrolidine-2-methoxy]
phenyl methyl]thiazolidine-2,4-dione and its salts;
5-[4-[N-[2,3-dihydro-5-benzyloxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione maleic acid salt;
5-[4-[N-[2,3-dihydro-5-benzyloxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione hydrochloride salt;
5-[4-[N-[2,3-dihydro-5-hydroxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione;
5-[4-[N-[2,3-dihydro-5-hydroxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2R)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione and its salts;
5-[4-[N-[2,3-dihydro-5-hydroxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione hydrochloride salt;
5-[4-[N-[2,3-dihydro-5-hydroxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione;
5-[4-[N-[2,3-dihydro-5-hydroxy-2,2,4,6,7-pentamethylbenz

furan-3-ylmethyl]-(2R)-pyrrolidine-2-methoxy]phenyl methylene]thiazolidine-2,4-dione
and its salts;
5-[4-[N-[5-benzyloxy-2-methylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione;
5-[4-[N-[5-benzyloxy-2-methylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene] thiazolidine-2,4-dione sodium salt, and
5-[4-[N-[(5-benzyloxy-2-methylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione.
[0027] According to a feature of the present invention, there is provided a process for
the preparation of novel intermediate of the general formula (III)

where A, B, D, X, Ar, k and p are as defined in formula (I) and G is as defined above.
[0028] In an embodiment of the invention, the novel intermediate of the general formula
(III) defined above where G is CHO or NO
2 group, can be prepared by reacting the compound of the general formula (IV),

wherein, A, B, D, X, k and p are as defined earlier and L
1 is a halogen atom such as chlorine, bromine or iodine or a leaving group such as
methanesulfonate, trifluoromethanesulfonate, p-toluenesulfonate and the like with
a compound of the formula (V)
HO―Ar―G (V)
where G is a CHO or a NO
2 group and Ar is as defined earlier.
[0029] The reaction of compound of formula (IV) with the compound of formula (V) to produce
a compound of formula (III) may be carried out in the presence of solvents such as
THF, DMF, DMSO, DME and the like. Mixtures of solvents may be used. An inert atmosphere
may be used and may be maintained by using inert gases such as N
2, Ar or He. The reaction may be effected in the presence of a base such as K
2CO
3, Na
2CO
3, NaH, or mixtures thereof. The reaction temperature may range from 20°C. to 150°C.,
preferably at a temperature in the range of 30°C. to 100°C. The duration of the reaction
may range from 1 to 24 hours, preferably from 2 to 6 hours.
[0030] In another embodiment of the present invention, the novel intermediate of general
formula (III), where G is a CHO or NO
2 group, can also be prepared by the reaction of compound of general formula (VI)

where A, B, D, X, k and p are as defined earlier with a compound of general formula
(VII)
L
2-Ar-G (VII)
where G is a CHO or NO
2 group and Ar is as defined earlier and L
2 represents a halogen atom such as chlorine or fluorine.
[0031] The reaction of compound of formula (VI) with a compound of formula (VII) to produce
a compound of the formula (III) may be carried out in the presence of solvents such
as THF, DMF, DMSO, DME and the like or mixtures thereof. The reaction may be carried
out in an inert atmosphere which is maintained by using inert gases such as N
2, Ar, or He. The reaction may be effected in the presence of a base such as K
2CO
3, Na
2CO
3 or NaH or mixtures thereof. The reaction temperature may range from 20°C. to 120°C.,
preferably at a temperature in the range of 30°C. to 100°C. The duration of the reaction
may range from 1 to 12 hours, preferably from 2 to 6 hours.
[0032] The novel intermediate of formula (III) can also be obtained by the reaction of a
compound of general formula (VI) defined above with a compound of general formula
(V) defined earlier.
[0033] The reaction of compound of general formula (VI) with a compound of general formula
(V) may be carried out using suitable coupling agents such as dicyclohexyl urea, triarylphosphine/dialkylazadicarboxylate
such as PPh
3/DEAD and the like. The reaction may be carried out in the presence of solvents such
as THF, DME, CH
2Cl
2, CHCl
3, toluene, acetonitrile, carbontetrachloride and the like. The reaction may be carried
out in an inert atmosphere which may be maintained by using inert gases such as N
2, Ar, or He. The reaction may be effected in the presence of DMAP, HOBT and they may
be used in the range of 0.05 to 2 equivalents, preferably 0.25 to 1 equivalents. The
reaction temperature may be in the range of 0°C. to 100°C., preferably at a temperature
in the range of 20°C. to 80°C. The duration of the reaction may range from 0.5 to
24 hours, preferably from 6 to 12 hours.
[0034] In another embodiment of this invention, there is provided a process for the preparation
of a compound of general formula (III) where G is a CHO or a NO2 group, and other
symbols are as defined earlier which comprises reacting a compound of general formula
(VIII)

where B, D, X, Ar and p are as defined earlier, with a compound of general formula
(IX)
A―(CH
2)
k―L
1 (IX)
where A, L
1 and k are as defined earlier.
[0035] The reaction of compound of general formula (VIII) with a compound of general formula
(IX) may be carried out neat or in the presence of solvents such as DMF, DMSO, CH
3CN, EtOH, or acetone. The reaction may be carried out in the inert atmosphere which
may be maintained by using inert gases such as N
2, Ar, or He. The reaction may be an inert atmosphere and effected in the presence
of base such as K
2CO
3, Na
2CO
3, KOH, NaOH, NaH and the like or mixtures thereof. The amount of base may range from
1 to 20 equivalents, preferably 1 to 10 equivalents. The reaction may be carried out
at a temperature in the range 20°C. to 180°C., preferably at a temperature in the
range 50°C. to 150°C. Duration of the reaction may range from 1 to 48 hours, preferably
from 1 to 12 hours. The amounts of the compound of general formula (VIII) and (IX)
may range from 1 to 20 equivalents, preferably from 1 to 5 equivalents.
[0036] The compound of general formula (VIII) in turn can be prepared by reacting a compound
of general formula (X)

where B, D, L
1, X and p are as defined earlier and R
3 is a hydrogen atom or a protecting group, with a compound of general formula (V)
followed by removal of N-protecting group using conventional methods.
[0037] The reaction of compound of general formula (X) with a compound of general formula
(V) may be carried out in the presence of solvents such as THF, DMF, DMSO, DME and
the like or mixtures thereof. The inert atmosphere may be maintained by using inert
gases such as N
2, Ar, or He. The reaction may be effected in the presence of a base such as K
2CO
3, Na
2CO
3, NaH and the like or mixtures thereof. The reaction temperature may range from 20°C.
to 120°C., preferably at a temperature in the range of 30°C. to 80°C. The duration
of the reaction may range from 1 to 24 hours, preferably from 2 to 12 hours.
[0038] The compound of general formula (VIII) can also be prepared by reacting a compound
of general formula (XI)

where B, D, X, p, and R
3 are as defined earlier, with a compound of general formula (V) or with a compound
of general formula (VII) defined earlier.
[0039] The reaction of compound of general formula (XI) with compound of general formula
(V) may be carried out out using suitable coupling agents such as dicyclohexyl urea,
triarylphosphine/dialkylazadicarboxylate such as PPh
3/DEAD and the like. The reaction may be carried out in the presence of solvents such
as THF, DME, CH
2Cl
2, CHCl
3, toluene, acetonitrile, carbontetrachloride and the like. The reaction may be carried
out in an inert atmosphere and it may be maintained by using inert gases such as N
2, Ar, or He. The reaction may be effected in the presence of DMAP, HOBT and they may
be used in the range of 0.05 to 2 equivalents, preferably 0.25 to 1 equivalents. The
reaction temperature may be in the range of 0°C. to 100°C., preferably at a temperature
in the range of 20°C. to 80°C. The duration of the reaction may range from 0.5 to
24 hours, preferably from 6 to 12 hours.
[0040] The reaction of compound of general formula (XI) with a compound of general formula
(VII) to produce a compound of general formula (VIII) may be carried out in the presence
of solvents such as THF, DMF, DMSO, DME and the like or mixtures thereof. The reaction
may be carried out in an inert atmosphere which is maintained by using inert gases
such as N
2, Ar, or He. The reaction may be effected in the presence of a base such as K
2CO
3, Na
2CO
3 or NaH or mixtures thereof. The reaction temperature may range from 20°C. to 120°C.,
preferably at a temperature in the range of 30°C. to 100°C. The duration of the reaction
may range from 1 to 12 hours, preferably from 2 to 6 hours.
[0041] The present invention provides a process for the preparation of novel azolidinedione
derivatives of general formula (I), their tautomeric forms, their stereoisomers, their
polymorphs, their pharmaceutically acceptable salts and their pharmaceutically acceptable
solvates wherein R
1 and Y together represent a bond and Z represents a sulfur or oxygen atom and all
symbols are as defined earlier which comprises:
reacting the compound of general formula (III), where G is a CHO group with 2,4-thiazolidinedione
or 2, 4- oxazolidinedione to yield a compound of general formula (XII)

where A, B, D, X, Ar, k, p and Z are as defined earlier and removing the water formed
during the reaction by conventional methods.
[0042] The reaction between the compound of the general formula (III) where G is a CHO group
with 2,4-thiazolidinedione or 2,4-oxazolidinedione to yield a compound of general
formula (XII) may be carried out neat in the presence of sodium acetate or in the
presence of a solvent such as benzene, toluene, methoxyethanol or mixtures thereof.
The reaction temperature may range from 80°C. to 140°C. depending upon the solvents
employed and in the range from 80°C. to 180°C. when the reaction is carried out neat
in the presence of sodium acetate. Suitable catalyst such as piperidinium acetate
or benzoate, sodium acetate or mixtures of catalysts may also be employed. Sodium
acetate can be used in the presence of solvent, but it is preferred that sodium acetate
is used neat. The water produced in the reaction may be removed, for example, by using
Dean Stark water separator or by using water absorbing agents like molecular sieves.
Oxazolidine-4-oxo-2-thione may be used instead of 2,4-oxazolidinedione. However, the
thio group needs to be converted to oxo group by oxidation using agents such as hydrogen
peroxide or peroxyacids like mCPBA.
[0043] The compound of the general formula (XII) obtained in the manner described above
is reduced by known methods to obtain the compound of general formula (XIII)

where A, B, D, X, Ar, k, p and Z are as defined earlier. The compound of general
formula (XIII) represents the compound of general formula (I), wherein R
1 is hydrogen and Y is CR
2 where R
2 is hydrogen atom and all other symbols are as defined earlier.
[0044] The reduction of compound of the formula (XII) to yield a compound of the general
formula (XIII) may be carried out in the presence of gaseous hydrogen and a catalyst
such as Pd/C, Rh/C, Pt/C, and the like. Mixtures of catalysts may be used. The reaction
may also be conducted in the presence of solvents such as dioxane, acetic acid, ethyl
acetate and the like. Mixtures of solvents may be used. A pressure between atmospheric
pressure and 80 psi may be employed. The catalyst may be 5 - 10 % Pd/C and the amount
of catalyst used may range from 50 - 300 % w/w. The reaction may also be carried out
by employing metal solvent reduction such as magnesium in methanol or sodium amalgam
in methanol. The reaction may also be carried out with alkali metal borohydrides such
as LiBH
4, NaBH
4, KBH
4 and the like in the presence of cobalt salt such as CoCl
2 and ligands, preferably bidentated ligands such as 2, 2'-bipyridyl; 1, 10-phenanthroline;
bisoximes and the like.
[0045] The compound of the general formula (XII) and of general formula (XIII) obtained
above may be converted into pharmaceutically acceptable salts, or pharmaceutically
acceptable solvates by conventional methods.
[0046] In yet another embodiment of the present invention, the compound of the general formula
(I) can also be prepared by reacting a compound of the general formula (IV) defined
above with a compound of general formula (XIV)

where R
1, Y, Z and Ar are as defined earlier and R
4 is hydrogen or a nitrogen protecting group which is removed after the reaction.
[0047] The reaction of compound of general formula (IV) with a compound of general formula
(XIV) to produce a compound of general formula (I) may be carried out in the presence
of solvents such as THF, DMF, DMSO, DME and the like or mixtures thereof. The reaction
may be carried out in an inert atmosphere which is maintained by using inert gases
such as N
2, Ar or He. The reaction may be effected in the presence of a base such as alkalis
like sodium hydroxide or potassium hydroxide; alkali metal carbonates like sodium
carbonate or potassium carbonate; alkali metal hydrides such as sodium hydride; organometallic
bases like n-butyl lithium; alkali metal amides like sodamide, or mixtures thereof.
Multiple solvents and bases can be used. The amount of base may range from 1 to 5
equivalents, preferably 1 to 3 equivalents. The reaction temperature may be in the
range of 0°C. to 120°C., preferably at a temperature in the range of 20°C. to 100°C.
The duration of the reaction may range from 0.5 to 24 hours, preferably from 0.5 to
6 hours.
[0048] The removal of protecting groups may be carried out by conventional methods which
include treatment with acid such as, hydrochloric acid, trifluoroacetic acid or bases
such as, KOH, NaOH, Na
2CO
3, NaHCO
3, K
2CO
3 and the like or mixtures thereof. These reagents may be used as aqueous solution
or as solutions in alcohols like methanol, ethanol etc. Deprotection can also be effected
by gaseous hydrogen in the presence of catalyst such as Pd/carbon or conventional
transfer hydrogenation methods when the protecting group is a benzyl or substituted
benzyl group.
[0049] The compound of general formula (I) can also be obtained by reacting a compound of
general formula (VI) with a compound of general formula (XIV).
[0050] The reaction of compound of general formula (VI) with a compound of general formula
(XIV) to produce a compound of general formula (I) may be carried out using suitable
coupling agents such as dicyclohexyl urea, triarylphosphine dialkylazadicarboxylate
such as PPh
3/DEAD, and the like. The reaction may be carried out in the presence of solvents such
as THF, DME, CH
2Cl
2, CHCl
3, toluene, acetonitrile, carbontetrachloride and the like. An inert atmosphere may
be used and the inert atmosphere may be maintained by using inert gases such as N
2, Ar, or He. The reaction may be effected in the presence of DMAP-HOBT and they may
be used in the range of 0.05 to 2 equivalents, preferably 0.25 to 1 equivalents. The
reaction temperature may be in the range of 0°C. to 100°C., preferably at a temperature
in the range of 20°C. to 80°C. The duration of the reaction may range from 0.5 to
24 hours, preferably from 6 to 12 hours.
[0051] In another embodiment of the present invention, the compound of general formula (I),
where A, B, D, X, k, p and Ar are as defined earlier and R' represents hydrogen, Y
represents CH and Z represents a oxygen or a sulfur atom can be prepared by the reaction
of compound of general formula (XV)

where A, B, D, X, k, p and Ar are as defined earlier, J is a halogen atom like chlorine,
bromine or iodine or a hydroxy group and R is a lower alkyl group, with thiourea when
J is a halogen atom, or with urea when J is a hydroxy group followed by treatment
with an acid.
[0052] The reaction of compound of general formula (XV) with thiourea or urea is normally
carried out in the presence of alcoholic solvent such as methanol, ethanol, propanol,
isobutanol, 2-methoxybutanol, etc or DMSO or sulfolane. The reaction may be conducted
at a temperature in the range between 20°C. and the reflux temperature of the solvent
used. Bases such as NaOAc, KOAc, NaOMe, NaOEt etc. can be used. The reaction is normally
followed by treatment with a mineral acid such as hydrochloric acid at 20°C. to 100°C.
[0053] The compound of general formula (XV) where J is hydroxy group is prepared by the
reaction of compound of general formula (XV) where J is a halogen atom with aqueous
alkali at a temperature ranging from 20°C. to 100°C. followed by reesterification
of the hydrolysed acid group during the reaction, by conventional methods.
[0054] The compound of general formula (XV) where J is a OH group may also be prepared from
compound of formula (XV) where J is a halogen atom by reacting with formamide in the
presence of water. The amount of formamide used in the reaction ranges from 0.5 to
1.5 mL and water used ranges from 20 µL to 0.1 mL for one mmol of the halo compound
(XV). The reaction is conducted at a temperature ranging from 80°C. to 180°C., preferably
from 120°C. to 150°C., over a period ranging from 1 to 8 hours.
[0055] The compound of general formula (XV) where J is a halogen atom can be prepared by
the diazotization of the amino compound of the general formula (XVI)

where all symbols are as defined earlier, using alkali metal nitrites followed by
treatment with acrylic acid esters in the presence of hydrohalo acids and catalytic
amount of copper oxide or copper halide.
[0056] The compound of general formula (XVI) can in turn be prepared by the conventional
reduction of the novel intermediate (III) where G is NO2 group and other symbols are
as defined earlier.
[0057] The intermediates of the formula (VI) defined above can be prepared by a process
which comprises reacting a compound of general formula (IX) defined earlier with a
compound of general formula (XVII)

where B, D, X and p are as defined earlier, and R
b is a hydroxy group or a group, such as carboxylic acid group, ester, amide, ether
and the like, which can be converted to hydroxy group by conventional methods.
[0058] The reaction of compound of general formula (XVII) with a compound of general formula
(IX) to yield a compound of general formula (VI) may be carried out in neat or in
the presence of solvents such as DMF, DMSO, CH
3CN, EtOH, or acetone. The reaction may be conducted in an inert atmosphere and the
inert atmosphere is maintained by using inert gases such as N
2, Ar, or He. The reaction may be effected in the presence of base such as K
2CO
3, Na
2CO
3, KOH, NaOH, NaH and the like. The amount of base may range from 1 to 20 equivalents,
preferably 1 to 10 equivalents. The reaction may be carried out at a temperature in
the range 20°C. to 180°C., preferably at a temperature in the range 50°C. to 150°C.
Duration of the reaction may range from 1 to 48 hours, preferably from 1 to 12 hours.
The amounts of the compound of general formula (XVII) and (IX) may range from 1 to
20 equivalents, preferably from 1 to 5 equivalents.
[0059] The compound of general formula (VI) where k = 1 can also be prepared by reacting
the compound of general formula (XVII) defined above in the presence of formaldehyde
solution or a source of formyl moiety thereof, with A-H where A may be substituted
or unsubstituted single or fused aromatic or heterocycle or their tautomeric forms.
Suitable catalyst may be employed.
[0060] The reaction of compound of general formula (XVII) with A-H to yield a compound of
general formula (VI) where k = 1, may be carried out using formaldehyde, paraformaldehyde,
POCl
3-DMF and the like. The reaction may be carried out in the presence of solvents such
as methanol, ethanol, 2-methoxyethanol or neat. These reagents may be used in the
range of 1 to 4 equivalents, preferably 1 to 2 equivalents. The reaction may be carried
out at a temperature in the range of -10°C to 100°C., preferably from 0°C. to 90°C.
Duration of the reaction may range from 1 to 24 hours, preferably from 2 to 12 hours.
[0061] In yet another embodiment of the present invention, the compound of general formula
(I), where A, B, D, X, Ar, k and p are as defined earlier and Y is nitrogen atom and
Z is oxygen atom can be prepared by a process which comprises : reaction of novel
intermediate of formula (III) defined earlier, where G represents a CHO group with
NH
2OH.HCl to yield a compound of general formula (III) where G represents CH=NOH group
and all symbols are as defined earlier, followed by metal borohydride reduction to
yield a compound of general formula (XVIII)

where all symbols are as defined earlier.
[0062] The reaction of compound of general formula (III), where G is CHO group and other
symbols are as defined earlier, with hydroxylamine hydrochloride is carried out in
solvents such as ethanol, methanol, THF, dioxane and the like following the conventional
method to make oximes. 1 to 10 equivalents of NH
2OH.HCl may be used, preferably, 2 to 5 equivalents. Bases such as alkali metal acetates
or ammonium acetate may be used. Reaction may be carried out in the presence of water.
Temperature in the range of 0°C. to reflux temperature of the solvent may be used.
The oxime obtained in the manner described above is reduced using reducing agents
such as alkali metal borohydrides like sodium borohydride or sodium cyanoborohydride
or borane reagents using conventional conditions to yield the compound of general
formula (XVIII).
[0063] The compound of general formula (XVIII) in turn is reacted with halocarbonyl isocyanate
or alkoxycarbonyl isocyanate to yield a compound of general formula (I) or with KOCN
to yield a compound of general formula (III) where G is CH
2N(OH)CONH
2, followed by treatment with carbonylating agents such as alkylhaloformate to produce
the compound of general formula (I) where A, B, D, X, Ar, p and k are as defined earlier,
Y represents nitrogen atom and Z is oxygen atom.
[0064] The reaction of compound of general formula (XVIII) with halocarbonyl isocyanate
such as chlorocarbonyl isocyanate or alkoxycarbonyl isocyanate such as ethoxycarbonyl
isocyanate may be carried out in inert solvents such as THF, dioxane, etc. at a temperature
in the range -15°C. to 50°C. The reaction may be carried out for 0.5 to 12 hours depending
on the substrates used for the reaction.
[0065] Alternatively, the compound of general formula (XVIII) may be treated with excess
of KOCN in organic acids such as acetic acid. Water may be used in the reaction. The
reaction may be carried out at a temperature in the range of 20°C. to 120°C. The product
isolated in the reaction is further treated with alkyl haloformate such as ethyl chloroformate
in the presence of 1 to 10 equivalents of alkali such as sodium hydroxide, potassium
hydroxide and the like to obtain compound of general formula (I) where all the symbols
are as defined earlier and Y represents nitrogen atom and Z represents oxygen atom.
[0066] The pharmaceutically acceptable salts are prepared by reacting the compound of formula
(I) with 1 to 4 equivalents of a base such as sodium hydroxide, sodium methoxide,
sodium hydride, potassium t-butoxide, calcium hydroxide, magnesium hydroxide and the
like, in solvents like ether, THF, methanol, t-butanol, dioxane, isopropanol, ethanol
etc. Mixture of solvents may be used. Organic bases like lysine, arginine, diethanolamine,
choline, guanidine and their derivatives etc. may also be used. Alternatively, acid
addition salts are prepared by treatment with acids such as hydrochloric acid, hydrobromic
acid, nitric acid, sulfuric acid, phosphoric acid, p-toluenesulphonic acid, methanesulfonic
acid, acetic acid, citric acid, maleic acid, salicylic acid, hydroxynaphthoic acid,
ascorbic acid, palmitic acid, succinic acid, benzoic acid, benzene sulfonic acid,
tartaric acid and the like in solvents like ethyl acetate, ether, alcohols, acetone,
THF, dioxane etc. Mixture of solvents may also be used.
[0067] The stereoisomers of the compounds forming part of this invention may be prepared
by using reactants in their single enantiomeric form in the process wherever possible
or by conducting the reaction in the presence of reagents or catalysts in their single
enantiomer form or by resolving the mixture of stereoisomers by conventional methods.
Some of the preferred methods include use of microbial resolution, resolving the diastereomeric
salts formed with chiral acids such as mandelic acid, camphorsulfonic acid, tartaric
acid, lactic acid and the like or chiral bases such as brucine, cinchona alkaloids
and their derivatives and the like.
[0068] Various polymorphs of compound of general formula (I) forming part of this invention
may be prepared by crystallization of compound of formula (I) under different conditions.
For example, using different solvents commonly used or their mixtures for recrystallization;
crystallizations at different temperatures; various modes of cooling, ranging from
very fast to very slow cooling during crystallizations. Polymorphs may also be obtained
by heating or melting the compound followed by gradual or slow cooling. The presence
of polymorphs may be determined by solid probe NMR spectroscopy, IR spectroscopy,
differential scanning calorimetry, powder X-ray data or such other techniques.
[0069] The present invention also provides a pharmaceutical composition, containing the
compounds of the general formula (I), as defined above, their tautomeric forms, their
stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically
acceptable solvates in combination with the usual pharmaceutically employed carriers,
diluents and the like, useful for the treatment and / or prophylaxis of diseases in
which insulin resistance is the underlying pathophysiological mechanism such as type
II diabetes, impaired glucose tolerance, dyslipidaemia, hypertension, coronary heart
disease and other cardiovascular disorders including atherosclerosis; insulin resistance
associated with obesity and psoriasis, for treating diabetic complications and other
diseases such as polycystic ovarian syndrome (PCOS), certain renal diseases including
diabetic nephropathy, glomerulonephritis, glomerular sclerosis, nephrotic syndrome,
hypertensive nephrosclerosis, end-stage renal diseases and microalbuminuria as well
as certain eating disorders, as aldose reductase inhibitors and for improving cognitive
functions in dementia.
[0070] The pharmaceutical composition may be in the forms normally employed, such as tablets,
capsules, powders, syrups, solutions, suspensions and the like, may contain flavorants,
sweeteners etc. in suitable solid or liquid carriers or diluents, or in suitable sterile
media to form injectable solutions or suspensions. Such compositions typically contain
from 1 to 25 %, preferably 1 to 15 % by weight of active compound, the remainder of
the composition being. pharmaceutically acceptable carriers, diluents or solvents.
[0071] A typical tablet production method is exemplified below:
Tablet Production Example
[0072]
| a) |
1) |
Active ingredient |
30 g |
| |
2) |
Lactose |
95 g |
| |
3) |
Corn starch |
30 g |
| |
4) |
Carboxy methyl cellulose |
44 g |
| |
5) |
Magnesium stearate |
1 g |
| |
|
|
 for 1000 tablets |
[0073] The ingredients 1-3 are uniformly blended with water and granulated after drying
under reduced pressure. The ingredients 4 & 5 are mixed well with the granules and
compressed by a tabletting machine to prepare 1000 tablets each containing 30 mg of
ingredient.
| b) |
1) |
Active ingredient |
30 g |
| |
2) |
Calcium phosphate |
90 g |
| |
3) |
Lactose |
40 g |
| |
4) |
Corn starch |
35 g |
| |
5) |
Polyvinyl pyrrolidone |
3.5 g |
| |
6) |
Magnesium stearate |
1.5 g |
| |
|
|
 for 1000 tablets |
[0074] The ingredients 1-4 are uniformly moistened with an aqueous solution of 5 and granulated
after drying under reduced pressure. Ingredient 6 is added and granules are compressed
by a tabletting machine to prepare 1000 tablets containing 30 mg of ingredient 1.
[0075] The compound of the formula (I) as defined above are clinically administered to mammals,
including man,
via either oral or parenteral routes. Administration by the oral route is preferred,
being more convenient and avoiding the possible pain and irritation of injection.
However, in circumstances where the patient cannot swallow the medication, or absorption
following oral administration is impaired, as by disease or other abnormality, it
is essential that the drug be administered parenterally. By either route, the dosage
is in the range of about 0. 10 to about 200 mg/kg body weight of the subject per day
or preferably about 0. 10 to about 50 mg/kg body weight per day administered singly
or as a divided dose. However, the optimum dosage for the individual subject being
treated will be determined by the person responsible for treatment, generally smaller
doses being administered initially and thereafter increments made to determine the
most suitable dosage.
[0076] Suitable pharmaceutically acceptable carriers include solid fillers or diluents and
sterile aqueous or organic solutions. The active compound will be present in such
pharmaceutical compositions in amounts sufficient to provide the desired dosage in
the range as described above. Thus, for oral administration, the compounds can be
combined with a suitable solid or liquid carrier or diluent to form capsules, tablets,
powders, syrups, solutions, suspensions and the like. The pharmaceutical compositions,
may, if desired, contain additional components such as flavorants, sweeteners, excipients
and the like. For parenteral administration, the compounds can be combined with sterile
aqueous or organic media to form injectable solutions or suspensions. For example,
solutions in sesame or peanut oil, aqueous propylene glycol and the like can be used,
as well as aqueous solutions of water-soluble pharmaceutically-acceptable acid addition
salts or alkali or alkaline earth metal salts of the compounds. The injectable solutions
prepared in this manner can then be, administered intravenously, intraperitoneally,
subcutaneously, or intramuscularly, with intramuscular administration being preferred
in humans.
[0077] The invention is explained in detail in the examples given below which are provided
by way of illustration only and therefore should not be construed to limit the scope
of the invention.
Preparation 1
N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methanol:
[0078]

[0079] A mixture of (2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl methanesulphonate
(100 g) and L-prolinol (100 g) was heated under nitrogen atmosphere at 120°C. with
stirring for 6 h. The mixture was cooled to room temperature and poured into water
and the solution was extracted with CH
2Cl
2 repeatedly. The combined organic extracts were washed with brine, dried (Na
2SO
4) and evaporated to dryness under reduced pressure to give 101 g (100 %) of the crude
compound which was chromatographed on silica gel using 0.5 % methanol in chloroform
to afford 75.7 g (75 %) of the title compound as a thick liquid.
[α]
D 27 = -9.5 (c, 1.0, CHCl
3).
1H NMR (CDCl
3, 200 MHz) : δ 1.19, 1.25 (2S, 3H), 1.55 - 2.05 (m, 6H), 2.11 (s, 3H), 2.18 (s, 3H),
2.22 (s, 3H), 2.35 - 3.0 (m, 6H), 3.25 - 3.75 (m, 3H), 4.7 (s, 2H), 7.2 - 7.6 (m,
5H).
Preparation 2
N-[(3RS)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methanol
[0080]

[0081] The title compound (1 g, 66 %) was prepared as a pale yellow solid from (3RS)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl
methanesulfonate (1.49 g) and L-prolinol (1.5 g) by an analogous procedure to that
described in preparation 1, mp 99 - 101°C.
[α]
D26 = -32.8 (c, 1.0, CHCl
3).
1H NMR (CDCl
3, 200 MHz) : δ 1.30, 1.34 (2s, 3H), 1.58, 1.62 ( 2s, 3H), 1.78 (m, 4H), 2.12 (s, 3H),
2.20, 2.22 (2s, 3H), 2.28, 2.30 (2s, 3H), 2.33 (m, 2H), 2.68 (d, J = 6.0 Hz, 1H),
3.09 (m, 1H), 3.30 (m, 2H), 3.36 (m, 1H), 3.68 (m, 1H), 4.76 (s, 2H), 7.46 (m, 5H).
Preparation 3
N-[5-Benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methanol:
[0082]

[0083] The title compound (7.5 g, 69 %) was prepared as a white solid from 5-benzyloxy-2,4,6,7-tetramethylbenzofuran-3-methylchloride
(9.0 g) and L-prolinol (4.15 g) by an analogous procedure to that described in preparation
1. mp 98 - 100°C.
[α]
D20 = -15.5 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.85 (m, 4H), 2.36 (s, 3H), 2.41 (s, 3H), 2.48 (s, 3H), 2.50 (m, 1H),
2.64 (s, 3H), 2.76 (m, 1H), 3.04 (m, 1H), 3.34 (dd, J = 10.8 and 2.5 Hz, 1H)), 3.51
(dd, J 10.2, 3.5 Hz, 1H), 3.60 (d, J = 13.2 Hz, 1H), 3.95 (d, J = 13.2 Hz, 1H), 4.78
(s, 2H), 7.48 (m, 5H).
Preparation 4
N-(5-Benzyloxy-2-methylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methanol
[0084]

[0085] The title compound (4.1 g, 67 %) was prepared as an oil from 5-benzyloxy-2-methylbenzofuran-3-methylchloride
(5.0 g) and L-prolinol (1.76 g) by an analogous procedure to that described in preparation
1.
[α]
D21 = -26.3 (c, 0.5, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.63 (m, 2H), 1.88 (m, 2H), 2.32 (m, 1H), 2.43 (s, 3H), 2.75 (m, 1H),
2.92 (m, 1H), 3.41 (m, 2H), 3.75 (dd, J = 10.7 Hz and 3.34 Hz, 1H), 3.90 (d, J = 13.3
Hz, 1H), 5.09 (s, 2H), 6.89 (m, 1H), 7.06 (m, 1H), 7.45 (m, 6H).
Preparation 5
N-(1-Methylindol-3-ylmethyl)-(2S)-pyrrolidine-2-methanol:
[0086]

[0087] To a mixture of formalin (0.33 ml, 48 % in H
2O) and acetic acid (0.9 ml) was added L-prolinol (0.43 g) with stirring under ice-cooling.
After 5 min, 1-methyl indole (0.56 g) was added dropwise to the above reaction mixture,
and stirring was continued for 2 h. At the end of this time, reaction mixture was
basified with 2N NaOH; the oily residue was extracted with ethyl acetate, dried (Na
2SO
4), and the solvent was evaporated to dryness to give the title compound (0.87 g, 83
%), as a white solid, mp. 46-48°C.
[α]
D25 = -65.1 (c, 1.0, CH
3OH)
1H NMR (CDCl
3, 200 MHz): δ 1.68 (m, 2H), 1.85 (m, 2H), 2.36 (q, J = 9.3 Hz and 16.9 Hz, 1H), 2.75
(m, 1H), 3.03 (m, 1H), 3.42 (d, J = 9.9 Hz, 1H), 3.56 (d, J = 13.3 Hz, 1H), 3.79 (m,
4H), 4.08 (d, J = 13.3 Hz, 1H), 6.96 (s, 1H), 7.20 (m, 3H), 7.70 (d, J = 7.75 Hz,
1H).
Preparation 6
1-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]piperazine:
[0088]

[0089] The title compound (7 g, 47 %) was prepared as a syrupy liquid from (2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl
methanesulphonate (15 g) and piperazine (19 g) by an analogous procedure to that described
in preparation 1.
1H NMR (CDCl
3, 200 MHz): δ 1.22 (s, 3H), 1.7 (m, 1H), 1.95 (m, 1H), 2.03 (s, 3H), 2.17 (s, 3H),
2.21 (s, 3H), 2.60 (m, 4H), 2.95 (m, 4H), 3.2 (m, 4H), 4.7 (s, 2H), 7.3 - 7.6 (m,
5H).
Preparation 7
N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(3R)-chloropiperidine:
[0090]

[0091] Thionyl chloride (6 ml) was added dropwise to a stirred, ice cooled solution of N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methanol
(17 g) obtained in preparation 1, in dry benzene (200 ml). The resulting mixture was
stirred at room temperature for 1 h and then diluted with ethyl acetate, washed with
saturated aqueous sodium bicarbonate solution, water, brine and dried (Na
2SO
4). The organic layer was evaporated and the residue was chromatographed on silica
gel using 12 % ethyl acetate in petroleum ether as eluent to give 13 g (73 %) of the
title compound as a thick liquid.
1H NMR (CDCl
3, 200 MHz): δ 1.24 (s, 3H), 1.4 - 2.5 (m, 8H), 2.1 (s, 3H), 2.18 (s, 3H), 2.23 (s,
3H), 2.53 (s, 2H), 2.63 (t, J = 6.8 Hz, 2H), 2.8 (m, 1H), 3.3 (m, 1H), 4.0 (m, 1H),
4.7 (s, 2H), 7.3 - 7.6 (m, 5H).
Preparation 8
N-[(3RS)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(3R)-chloropiperidine:
[0092]

[0093] The title compound (0.85 g, 90 %) was prepared as a pale yellow solid from the product
(0.9 g) obtained in preparation 2 and thionylchloride (0.79 ml) by a similar procedure
to that used in preparation 7.
1H NMR (CDCl
3, 200 MHz): δ 1.35 (s, 3H), 1.62 (bs, 5H), 1.80 (m, 2H), 2. 11 (s, 3H), 2.23 (s, 6H),
2.30 (m, 2H), 2.53 (m, 2H), 2.86 (m, 1H), 3.06 (m, 1H), 3.22 (m, 1H), 4.0 (m, 1H),
4.71 (s, 2H), 7.43 (m, 5H).
Preparation 9
[N-(5-Benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(3R)-chloropiperidine:
[0094]

[0095] The title compound (2g, 63 %) was prepared as a white solid from N-(5-benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methanol
(3.0 g) obtained in preparation 3 and thionylchloride (2.78 ml) by a similar procedure
to that used in preparation 7. mp 90 - 92°C.
[α]
D20 = -49.7 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.68 (m, 3H), 2.19 (m, 3H), 2.36 (s, 3H), 2.45 (s, 6H), 2.62 (s, 3H),
2.78 (m, 1H), 3.13 (m, 1H), 3.51 (d, J = 6.2 Hz, 2H), 3.92 (m, 1H), 4.72 (s, 2H),
7.47 (m, 5H).
Preparation 10
N-(5-benzyloxy-2-methylbenzofuran-3-ylmethyl)-(3R)-chloropiperidine:
[0096]

[0097] The title compound (2.3 g, 100 %) was prepared as an oil from N-(5-benzyloxy-2-methylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methanol
(2.25 g) obtained in preparation 4 and thionylchloride (2.34 ml) by a similar procedure
to that used in preparation 7.
[α]
D25 = -20.6 (c, 1.83, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.62 (m, 3H), 2.20 (m, 3H), 2.39 (s, 3H), 2.68 (m, 1H), 3.05 (m, 1H),
3.54 (s, 2H), 3.89 (m, 1H), 5.11 (s, 2H), 6.88 (m, 1H), 7.42 (m, 7H).
Preparation 11
N-(1-Methylindol-3-ylmethyl)-(2S)-pyrrolidine-2-methyl methanesulfonate:
[0098]

[0099] To an ice cooled solution of the product (0.5 g) obtained in preparation 5 and triethylamine
(0.85 ml) in CH
2Cl
2 (10 ml) was added methanesulfonyl chloride (0.2 ml). The mixture was stirred at 5°C.
for 2 h. At the end of this time, the reaction mixture was washed with aqueous NaHCO
3 solution followed by H
2O, dried (CaCl
2) and concentrated to get 0.65 g (98 %) of the title compound. The crude product was
used in the next step without further purification.
Preparation 12
2-[4-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]piperazine-1-yl]ethanol:
[0100]

[0101] To a mixture of 1-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]piperazine
(2.3 g) obtained in preparation 6 and 2-bromoethanol (0.62 ml) in dry DMSO (15 ml),
K
2CO
3 (2.4 g) was added and the mixture was stirred at room temperature for 12 h. At the
end of this time, the reaction mixture was cooled, added water and extracted with
EtOAc. The EtOAc extract was washed with water followed by brine and dried over anhydrous
sodium sulphate. The solvent was then removed by distillation under reduced pressure
and the resulting crude compound was chromatographed on silica gel using 1 % methanol
in chloroform to afford (0.7 g, 27 %) the pure compound as a thick liquid.
1H NMR (CDCl
3, 200 MHz): δ 1.24 (s, 3H), 1.7 (m, 1H), 2.0 (m, 1H), 2.07 (s, 3H), 2.18 (s, 3H),
2.22 (s, 3H), 2.5 - 3.0 (m, 14 H), 3.68 (t, J = 5.2 Hz, 2H), 4.7 (s, 2H), 7.3 - 7.6
(m, 5H).
Preparation 13
2-[4-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]piperazine-1-yl]ethyl
chloride:
[0102]

[0103] The title compound (0.2 g, 33 %) was prepared as a thick liquid from the product
(0.6 g) obtained in preparation 12 and thionyl chloride (0.2 ml) by a similar procedure
to that used in preparation 7.
1H NMR (CDCl
3, 200 MHz): δ 1.24 (s, 3H), 1.7 (m, 1H), 2.0 (m, 1H), 2.07 (s, 3H), 2.17 (s, 3H),
2.22 (s, 3H), 2.4 - 2.8 (m, 14H), 3.6 (t, J = 7 Hz, 2H), 4.7 (s, 2H), 7.3 - 7.6 (m,
5H).
Preparation 14
a) 4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]benzaldehyde
(14a)
[0104]

and
b) 4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(3R)-piperidinyloxy]benzaldehyde
(14b)
[0105]

Method A
[0106] To a mixture of N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(3R)-chloropiperidine
(5 g) obtained in preparation 7 and 4-hydroxybenzaldehyde (1.7g) in dry DMF, K
2CO
3 (6.4 g) was added and the mixture was stirred at 80°C. for 2 h. At the end of this
time, the mixture was cooled, water added and extracted with EtOAc. The EtOAc extract
was washed with 5 % aqueous Na
2CO
3 solution, followed by brine and dried over anhydrous sodium sulphate. The solvent
was then removed by distillation under reduced pressure to give 4.2 g (70 %) of the
crude product as a mixture of
14a and
14b (1:1), which was separated by column chromatography on silica gel using 2 to 10 %
(gradient elution) ethyl acetate in petroleum ether to afford
14a (2.0 g, 33 %, as a syrupy liquid) and
14b (2.1 g, 35 % as semi solid).
Method B
[0107] To a mixture of N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methanol
(16 g) obtained in preparation 1, 4-hydroxybenzaldehyde (5.2 g) and triphenyl phosphine
(11.8 g) in THF (200 ml), diisopropyl azodicarboxylate (15 ml) was added and the mixture
was stirred at room temperature (30°C.) for 1 h. At the end of this time, it was diluted
with EtOAc, washed with water, dried (Na
2SO
4) and concentrated under reduced pressure to give a mixture of
14a and
14b (1.1 : 1.0) which was separated by column chromatography using 2 to 10 % (gradient
elution) ethyl acetate in petroleum ether to give
14a (8.2 g, 41 %, as a syrupy liquid) and
14b (8g, 40 %, as a semi solid).
14a: 1H NMR (CDCl
3, 200 MHz): δ 1.2 (s, 3H), 1.5 - 2.05 (m, 6H), 2.09 - 2.3 (6s, 9H), 2.35 - 3.2 (m,
6H), 3.4 (m, 1H), 3.8 (m, 1H), 4.05 (m, 1H), 4.7 (s, 2H), 7.0 (m, 2H), 7.3 - 7.6 (m,
5H), 7.75 (m, 2H), 9.9 (s, 1H).
14b: 1H NMR (CDCl
3, 200 MHz): δ 1.2, (s, 3H), 1.3 - 2.7 (m, 12H), 1.9 (s, 3H), 2.09 (s, 3H), 2.12 (s,
3H), 2.8 (m, 1H), 3.25 (m, 1H), 4.4 (m, 1H), 4.62 (s, 2H), 6.9 (m, 2H), 7.2 - 7.6
(m, 5H), 7.78 (m, 2H), 9.8 (s, 1H).
Preparation 15
a) 3-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]benzaldehyde
(15):
[0108]

[0109] The title compound
15 (1.5 g, 35 %) was prepared as a thick liquid from N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)-(3R)-chloropiperidine
(3.5 g), obtained in preparation 7 and 3-hydroxybenzaldehyde (1.2 g) in a similar
manner to that described in Method A of preparation 13. The crude compound was chromatographed
on silica gel to get
15.
1H NMR (CDCl
3, 200 MHz): δ 1.21, 1.28 (2s, 3H), 1.50 - 2.05 (m, 6H), 2.11 - 2.23 (m, 9H), 2.35
- 3.25 (m, 6H), 3.40 (m, 1H), 3.85 (m, 1H), 4.05 (m, 1H), 4.70 (m, 2H), 7.10 - 7.60
(m, 9H), 9.97, 9.99 (2s, 1H).
Preparation 16
4-[N-[(3R/S)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]benzaldehyde
(16):
[0110]

[0111] The title compound (1.6, 5g, 22 %) was prepared as an oil from N-[(3R/S)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethyl-benzofuran-3ylmethyl]-(3R)-chloropiperidine
(6.4 g) obtained in preparation 8 and 4-hydroxybenzaldehyde (1.83 g) in a similar
manner to that described in, method A of preparation 14. The crude compound was chromatographed
on silica gel to get 16.
1H NMR (CDCl
3, 200 MHz): δ 1.35 (s, 3H), 1.64 (s, 3H), 1.80 (m, 4H), 2.12 (s, 3H), 2.21 (s, 3H),
2.30 (s, 3H), 2.45 (m, 2H), 2.78 (m, 1H), 3.15 (m, 2H), 3.35 (m, 1H), 3.89 (m, 1H),
4.08 (m, 1H), 4.75 (s, 2H), 6.96 (d, J = 10.4 Hz, 2H), 7.44 (m, 5H), 7.85 (d, J =
10.4 Hz, 2H), 9.94 (s, 1H).
Preparation 17
3-[N-((3R/S)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]benzaldehyde:
[0112]

[0113] The title compound (0.8 g, 11 %) was prepared as an oil from N-[(R/S)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(3R)-chloropiperidine
(6.0g) obtained in preparation 8 and 3-hydroxybenzaldehyde (1.71 g) in a similar manner
to that described in method A of preparation 14. The crude compound was chromatographed
on silica gel to get 17.
[α]
D21 = -81.7 (c, 1.24, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.34 (s, 3H), 1.60 (s, 3H), 1.83 (m, 4H), 2.09 (s, 3H), 2.19 (8, 3H),
2.27 (s, 3H), 2.32 (m, 2H), 2.78 (m, 1H), 3.19 (m, 2H), 3.35 (m, 1H), 3.85 (dd, J
= 9.0 and 6.0 Hz, 1H), 4.04 (dd, J = 9.0 and 5.0 Hz, 1H), 4.72 (s, 2H), 7.17 (m, 1H),
7.48 (m, 8H), 9.97 (s, 1H).
Preparation 18
a) 4-[N-(5-Benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]]benzaldehyde (18a):
[0114]

and
b) 4-[N-[5-Benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl]-(3R)-piperidinyloxy]
benzaldehyde (18b):
[0115]

[0116] The title compounds
18a and
18b were prepared from N-(5-benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(3R)-chloropiperidine
(3 g) obtained in preparation 9 and 4-hydroxybenzaldehyde (0.889 g) in a similar manner
to_that described in method A of preparation 14. The crude compound was chromatographed
on silica gel to get
18a (1.0 g, 27 %) as an oil and
18b (0.89g, 22%) as a white solid, mp: 142-144°C.
18a: [α]
D22 = + 51.0 (c, 1.0, CH
2Cl
2)
1H NMR (CDCl
3, 200 MHz): δ 1.80 (m, 4H), 2.08 (m, 1H), 2.30 (s, 3H), 2.37 (s, 3H), 2.42 (s, 3H),
2.59 (s, 3H), 3.03 (m, 2H), 3.59 (d, J = 12.9 Hz, 1H), 3.79 (dd, J = 9.6 Hz and 6.8
Hz, 1H), 3.93 (dd, J = 9.6 Hz and 5.2 Hz, 1H), 4.05 (d, J = 12.9 Hz, 1H), 4.70 (s,
2H), 6.80 (d, J = 8.6 Hz, 2H), 7.48 (m, 5H), 7.77 (d, J = 8.6 Hz, 2H), 9.86 (s, 1H).
18b: [α]
D23 = - 57.5 (c, 0.2, CH
2Cl
2)
1H NMR (CDCl
3, 200 MHz): δ 1.74 (m, 4H), 2.18 (m, 2H), 2.29 (s, 3H), 2.32 (s, 6H), 2.62, (s, 3H),
2.73 (m, 1H), 3.05 (m, 1H), 3.45 (d, J = 5.4 Hz, 2H), 4.40 (m, 1H), 4.77 (s, 2H),
6.91 (d, J = 8.6 Hz, 2H), 7.49 (m, 5H), 7.75 (d, J = 8.7 Hz, 2H), 9.84 (s, 1H).
Preparation 19
4-[N-[5-Benzyloxy-2-methylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy] benzaldehyde
(19):
[0117]

[0118] The title compound (0.25 g, 41 %) was prepared as an oil from N-(5-benzyloxy-2 methylbenzofuran-3-ylmethyl)-(3R)-chloropiperidine
(0.5 g) obtained in preparation 10 and 4-hydroxybenzaldehyde (0.247 g) in a similar
manner to that described in method A of preparation 14. The crude compound was chromatographed
on silica gel to get 19.
[α]
D25 = -6.9 (c, 0.28, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.73 (m, 3H), 2.04 (m, 1H), 2.32 (m, 1H), 2.41 (s, 3H), 2.99 (m, 2H),
3.60 (d, J = 13.3 Hz, 1H), 4.02 (m, 2H), 4.12 (d, J = 13.3 Hz, 1H), 4.90 (d, J = 4.1
Hz, 2H), 6.86 (m, 1H), 6.96 (d, J = 8.5 Hz, 2H), 7.36 (m, 7H), 7.77 (d, J = 8.6 Hz,
2H), 9.81 (s, 1H).
Preparation 20
4-[N-[1-Methylindol-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]benzaldehyde:
[0119]

[0120] The title compound (0.16 g, 29 %) was prepared as a viscous oil from N-[1-methylindol-3-ylmethyl]-(2S)-pyrrolidine-2-methyl
methanesulfonate (0.5 g), obtained in preparation 11 and 4-hydroxybenzaldehyde (0.2
g), in a similar manner to that described in method A of preparation 14.
[α]
D22 = -30.65 (c, 1.65, CHCl
3).
1H NMR (CDCl
3, 200 MHz): δ 1.5 (m, 4H), 3.04 (m, 1 H), 3.76 (m, 3H), 3.84 (s, 3H), 4.22 (m, 1H),
4.56 (m, 2H), 7.02 (d, J = 7.8 Hz, 2H), 7.34 (m, 4H), 7.66 (d, J = 7.8 Hz, 1H), 7.88
(m, 2H), 9.94 (s, 1H)
Preparation 21
4-[2-[4-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)piperazine-1-yl]ethoxy]benzaldehyde:
[0121]

[0122] The title compound (0.2 g, 84 %) was prepared as a thick liquid from 2-[4-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)piperazin-1-yl]ethyl
chloride (0.2 g), obtained in preparation 13 and 4-hydroxybenzaldehyde (0.06 g) in
a similar manner to that described in method A of preparation 14.
1H NMR (CDCl
3, 200 MHz): δ 1.25 (s, 3H), 1.7 (m, 1H), 2.0 (m, 1H), 2.07 (s, 3H), 2.18 (s, 3H),
2.22 (s, 3H), 2.4 - 2.8 (m, 12H), 2.86 (t, J = 5.8 Hz, 2H), 4.2 (t, J = 5.8 Hz, 2H),
4.7 (s, 2H), 7.0 (d, J = 8.4 Hz, 2H), 7.3 - 7.6 (m, 5H), 7.83 (d, J = 8.4 Hz, 2H),
9.9 (s, 1H).
Preparation 22
4-[2-[4-(1-Methylindol-3-ylmethyl)piperazin-1-yl]ethoxy]benzaldehyde:
[0123]

[0124] A suspension of 1-(l-methylindole-3-ylmethyl)piperazine (1.3 g) in dimethylsulfoxide
(15 ml) and potassium hydroxide (0.63 g) was stirred for 30 min under nitrogen at
22°C. and then a solution of 4-[2-bromoethoxy]benzaldehyde (1.3 g) was added and stirring
was continued for further 4 h. The reaction mixture was diluted with water and extracted
with ethyl acetate and the organic layer was washed with water, brine, dried (Na
2SO
4) and solvent was evaporated under reduced pressure. The crude product was chromatographed
on silica gel using mixture of methanol: chloroform (1:9) as eluent to afford the
pure product (0.76 g, 51 %) as an oil.
1H NMR (CDCl
3, 200 MHz): δ 2.61 (bs, 8H), 2.83 (t, J = 5.72 Hz, 2H), 3.73 (s, 2H), 3.76 (s, 3H),
4.16 (t, J = 5.72 Hz, 2H), 6.98 (d, J = 8.5 Hz, 2H), 7.28 (m, 4H), 7.70 (d, J = 7.9
Hz, 1H), 7.81 (d, J = 8.5 Hz, 2H), 9.87 (s, 1H).
Preparation 23
4-[N-(3,5-Dimethyl-4-methoxy-2-pyridyl methyl]-(2S)-pyrrolidine-2-methoxy]benzaldehyde:
[0125]

[0126] A solution of N-[(3,5-dimethyl-4-methoxy-2-pyridyl methyl)-(2S)-pyrrolidine-2-methanol
(2.5 g) in 5 ml of dimethyl formamide (5 ml) was added dropwise while cooling to a
suspension of (60 % w/w dispersion) sodium hydride (0.48 g) in dimethyl formamide
(20 ml). The mixture was then stirred for 1 h at room temperature, after which 4-fluorobenzaldehyde
(1.3 ml) in dimethyl formamide (5 ml) was added dropwise at room temperature. The
reaction mixture was then stirred at 70°C. for 12 h. At the end of this time, water
was added to the reaction mixture and extracted with EtOAc, dried and concentrated
under reduced pressure to get 1.8 g (51 %) of the title compound. The crude product
was used in the next step without further purification.
Preparation 24
4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]nitrobenzene:
[0127]

[0128] A solution of 16 g of the product obtained in preparation 1 in dimethyl formamide
(100 ml) was added dropwise to a suspension of (50 % w/w dispersion) sodium hydride
(2.81 g) in dimethyl formamide (50 ml). The mixture was then stirred at room temperature
for 0.5 h, after which 1-fluoro-4-nitrobenzene (6.6 g) was added dropwise and the
mixture was then stirred at the same temperature for 2 h. At the end of this time,
water was added and the mixture was extracted with ethyl acetate, dried (Na
2SO
4), and the solvent was removed by distillation under reduced pressure to give 20 g
of the crude compound which was chromatographed on silica gel using 10 to 20 % (gradient
elution) of ethyl acetate in petroleum ether to afford 16.8 g (81%) of the title compound
as a thick liquid.
1H NMR (CDCl
3, 200 MHz): δ 1.25 (m, 3H), 1.55 - 3.2 (complex, 21H), 3.4 (m, 1H), 3.85 (m, 1H),
4.1 (m, 1H), 4.7 (s, 2H), 6.9 (m, 2H), 7.3 - 7.6 (m, 5H), 8.2 (m, 2H).
Preparation 25
4-[N-((3RS)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]nitrobenzene:
[0129]

[0130] The title compound (7.25g, 67 %) was prepared as an oil from N-[(3RS)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methanol
(8.4g) obtained in preparation 2 and 4-fluoronitrobenzene (2.6 ml) by a similar procedure
to that used in preparation 24.
1H NMR (CDCl
3, 200 MHz): δ 1.29 (s, 3H), 1.35 (s, 3H), 1.56 (s, 3H), 1.59 (s, 3H), 1.85 (m, 8H),
2.06 (s, 3H), 2.09 (s, 3H), 2.12 (s, 3H), 2.20 (s, 3H), 2.27 (s, 6H), 2.45 (m, 3H),
2.82 (m, 3H), 3.0 (m, 1H), 3.18 (m, 4H), 3.38 (m, 1H), 3.58 (m, 2H), 3.86 (m, 1H),
4.08 (m, 1H), 4.65 (d, J = 7.8 Hz, 2H), 4.72 (s, 2H), 6.74 (d, J = 9 Hz, 2H), 6.93
(d, J = 9 Hz, 2H), 7.48 (m, 10H), 8.13 (d, J = 9 Hz, 2H), 8.19 (d, J = 9 Hz, 2H).
Preparation 26
4-[N-[5-Benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]nitrobenzene:
[0131]

[0132] The title compound (25 g, 79 %) was prepared as an yellow solid from N-[5-benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methanol
(24 g) obtained in preparation 3 and 4-fluoronitrobenzene (11.19 g) by a similar procedure
to that used in preparation 24. mp. 136 -139°C.
1H NMR (CDCl
3, 200 MHz): δ 1.78 (m, 4H), 2.06 (m, 1H), 2.32 (s, 3H), 2.38 (8, 3H), 2.43 (s, 3H),
2.59 (s, 3H), 3.03 (m, 2H), 3.63 (d, J = 12.8 Hz, 1H), 3.85 (m, 2H), 4.0 (d, J = 12.8
Hz, 1H), 4.72 (s, 2H), 6.72 (d, J = 9 Hz, 2H), 7.45 (m, 5H), 8.13 (d, J = 9 Hz, 2H).
Preparation 27
4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2ylmethyl]-(2S)-pyrrolidine-2-methoxy]aniline:
[0133]

[0134] 4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]
nitrobenzene (5.8 g) obtained in preparation 24 was dissolved in EtOAc (30 ml) and
was reduced with hydrogen (60 psi) in the presence of 10 % palladium on charcoal (0.6
g) at ambient temperature until hydrogen uptake (nearly 6 h) ceased. The solution
was filtered through a bed of celite, the filter pad was washed exhaustively with
EtOAc. The combined filtrate was evaporated to dryness under reduced pressure. The
crude product was chromatographed on silica gel using 2 to 10 % (gradient elution)
of methanol in chloroform to afford 5 g (91 %) of the title compound as a thick liquid.
1H NMR (CDCl
3, 200 MHz): δ 1.2, 1.3 (2s, 3H), 1.5 - 3.2 (complex, 12 H), 2.1 (s, 3H), 2.15 (s,
3H), 2.2 (s, 3H), 3.4 (m, 1H), 3.75 (m, 1H), 3.9 (m, 1H), 4.7 (s, 2H), 6.7 (m, 4H),
7.4 (m, 5H).
Preparation 28
4-[N-[(3RS)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]aniline:
[0135]

[0136] The title compound (5. 1 g, 55 %) was prepared as a brown oil from 4-[N-[(3RS)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]
nitrobenzene (9.8 g) obtained in preparation 25, by a similar procedure to that described
in preparation 27.
1H NMR (CDCl
3, 200 MHz): δ 1.31, 1.33 (2s, 3H), 1.56, 1.61 (2s, 3H), 1.84 (m, 4H), 2.10 (s, 3H),
2.22 (s, 3H), 2.28 (s, 3H), 2.45 (m, 2H), 2.79 (m, 1H), 3.12 (m, 2H), 3.35 (m, 1H),
3.75 (m, 1H), 3.98 (m, 1H), 4.75 (m, 2H), 6.68 (m, 4H), 7.46 (m, 5H).
Preparation 29
4-[N-[5-Benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]aniline:
[0137]

[0138] The title compound (3.3 g, 70 %) was prepared as a thick liquid from 4-[N-[5-benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]nitrobenzene
(5g) obtained in preparation 26 by a similar procedure to that described in preparation
27.
1H NMR (CDCl
3, 200 MHz): δ 1.61 (m, 4H), 2.10 (m, 1H), 2.29 (s, 3H), 2.34 (s, 3H), 2.40 (s, 3H),
2.65 (s, 3H), 2.96 (m, 2H), 3.41 (bs, exchangeable with D
2O, 2H), 3.48 (d, J = 13 Hz, 1H), 3.65 (m, 1H), 3.85 (m, 1H), 4.12 (d, J = 13 Hz, 1H),
4.75 (s, 2H), 6.62 (s, 4H), 7.48 (m, 5H).
Preparation 30
Ethyl-2-bromo-3-[4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl]propanoate:
[0139]

[0140] A solution of NaNO
2 (0.72 g) in H
2O (1.3 ml) was added dropwise to a stirred and ice cooled mixture of 4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2ylmethyl]-(2S)-pyrrolidine-2-methoxy]aniline
(4.8 g) obtained in preparation 27, aqueous HBr (48 %, 6.5 ml) MeOH (8.8 ml) and acetone
(21 ml) below 5°C. The solution was stirred at 5°C. for 30 min and ethyl acrylate
(6 ml) was added and the temperature was raised to 38°C. Powdered Cu
2O (77 mg) was added in small portions to the vigorously stirred mixture. After the
N
2 gas evolution has ceased, the reaction mixture was concentrated in vacuo. The residue
was diluted with water, made alkaline with concentrated NH
4OH and extracted with EtOAc. The EtOAc extract was washed with brine, dried (Na
2SO
4) and concentrated in vacuum. The crude product was chromatographed on silica gel
using 10 - 20 % (gradient elution) of ethyl acetate in petroleum ether to afford 3.0
g (47 %) of the title compound as a thick liquid.
1H NMR (CDCl
3, 200 MHz): δ 1.2 (m, 6H), 1.55 - 3.5 (complex, 15H), 2.1 (s, 3H), 2.15 (s, 3H), 2.2
(s, 3H), 3.75 (m, 1H), 3.9 (m, 1H), 4.2 (m, 2H), 4.35 (m, 1H), 4.7 (s, 2H), 6.7 (m,
2H), 7.1 (m, 2H), 7.3 - 7.6 (m, 5H).
Preparation 31
Ethyl 2-bromo-3[4-[N-[(3RS)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethyl benzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]
phenyl]propanoate:
[0141]

[0142] The title compound (2.5 g, 38 %) was prepared as an oil from 4-[N-[(3RS)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]aniline
(5 g), obtained in preparation 28, by a similar procedure to that described in preparation
30.
1H NMR (CDCl
3, 200 MHz): δ 1.26 (m, 6H), 1.58, 1.60 (2s, 3H), 1.76 (m, 4H), 2.08 (s, 3H), 2.22
(s, 3H), 2.28 (s, 3H), 2.42 (m, 2H), 2.78 (m, 1H), 2.99 (m, 1H), 3.15 (m, 2H), 3.32
(m, 1H), 3.56 (m, 1H), 3.72 (m, 1H), 3.96 (m, 1H), 4.15 (q, J = 6 Hz, 2H), 4.33 (m,
1H), 4.71 (m, 2H), 6.68 (d, J = 8 Hz, 1H), 6.76 (d, J = 8 Hz, 1H), 7.10 (m, 2H), 7.45
(m, 5H).
Preparation 32
Ethyl 2-bromo-3-[4-[N-[5-benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl]propanoate:
[0143]

[0144] The title compound (2.8 g, 14 %) was prepared as a viscous oil from 4-[N-[5-benzyloxy-
2,2,4,6,7-tetramethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]aniline (15
g), obtained in preparation 29, by a similar procedure to that described in preparation
30.
1H NMR (CDCl
3, 200 MHz): δ 1.26 (t, J = 7 Hz, 3H), 1.79 (m, 4H), 2.05 (m, 1H), 2.31 (s, 3H), 2.39
(s, 3H), 2.42 (s, 3H), 2.65 (s, 3H), 2.98 (m, 2H), 3.21 (m, 1H), 3.40 (m, 1H), 3.58
(d, J = 12 Hz, 1H), 3.74 (m, 1H), 3.91 (m, 1H), 4.21 (m, 4H), 4.76 (s, 2H), 6.73 (d,
J = 7.7 Hz, 2H), 7.10 (d, J = 7.7 Hz, 2H), 7.48 (m, 5H).
Example 1
5-[4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione:
[0145]

[0146] A solution of 4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]benzaldehyde
(1.2 g) obtained in preparation 14 and 2,4-thiazolidinedione (0.27 g) in toluene (30
ml) containing piperidine (30 mg) and benzoic acid (37 mg) was heated at reflux for
2 h using Dean-Stark apparatus. The reaction mixture was cooled, diluted with EtOAc
and filtered, the filtrate was washed with H
2O, dried (Na
2SO
4) and evaporated under reduced pressure (1.4 g, 100 %).
Preparation of polymorphs
Form 1
[0147] The product (0.5 g) obtained in example 1 was dissolved in 5 ml of EtOAc and the
solution was heated at 80°C. At this temperature 2 ml of pet. ether was added dropwise
and the resulting solution was filtered through a cotton plug and allowed to stay
at 0°C. for 12 h. The resulting solid (220 mg, 44 %) as pale yellow granules was filtered,
washed with petroleum ether and dried under vacuum. mp 186.6°C.
1H NMR (CDCl
3, 200 MHz): δ identical with that of Form 3.
Form 2
[0148] The compound (500 mg) obtained in example 1 was taken in a single neck RB flask equipped
with N
2 and inlet was heated at 100°C. until the solid melts (5 min). Then the RB flask was
immersed in an ice bath to get a deep yellow amorphous solid (500 mg, 100 %) mp: 88°C.
1H NMR (CDCl
3, 200 MHz): δ identical with that of Form 3.
Form 3
[0149] The crude product obtained above was chromatographed on silica gel using 0 to 0.5
% (gradient elution) of methanol in chloroform to afford 1.3 g (93 %) of the title
compound as a pale yellow fluffy solid. mp. 86°C.
[α]
D24 = - 17.3 (c, 1.0, CDCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.21, 1.26 (2s, 3H), 1.5 - 2.05 (m, 6H), 2.08 - 2.22 (6s, 9H), 2.35
- 3.15 (m, 6H), 3.4 (m, 1H), 3. 8 (m, 1H), 4.0 (m, 1H), 4.7 (s, 2H), 6.95 (m, 2H),
7.3 - 7.6 (m, 7H), 7.8 (s, 1 H).
Example 2
5-[4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione, maleate:
[0150]

[0151] To a solution of 5-[4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione (250 mg), obtained in example 1, in dry Et
2O (5 ml) at room temperature, maleic acid (47 mg) in Et
2O (5 ml) was added. The reaction mixture was stirred for an additional 30 min. and
the Et
2O layer was decanted. The resulting solid was washed twice with Et
2O (2 x 5 ml) and dried under reduced pressure over P
2O
5 for 6 h to get a pale yellow solid (220 mg, 74 %). mp: 210°C.
[α]
D27 = 27.0 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.25, 1.3 (2s, 3H), 1.95, 2.0,2.1 (3s, 9H), 1.5 - 4.5 (complex m, 15
H), 4.65 (2s, 2H), 6.1 (s, 2H), 7.0 - 7.7 (m, 9H), 7.8 (s, 1H).
Example 3
5-[4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione, sodium salt:
[0152]

[0153] To a solution of 5-[4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione (250 mg), obtained in example 1, in dry Et
2O (15 ml) at room temperature, NaOMe in MeOH [prepared in situ by dissolving Na (13
mg) in MeOH (1 ml)] was added. The reaction mixture was stirred at room temperature
for 30 min and the supernatant solvent was decanted. The resulting solid was washed
twice with Et
2O (2 x 5 ml) and dried over P
2O
5 under reduced pressure for 6 h to get a pale yellow solid (235 mg, 65 %), mp : 245°C.
[α]
D27 = -9.3 (c, 0.82, CHCl
3).
1H NMR (CDCl
3, 200 MHz): δ 1.15, 1.2 (2s, 3H), 2.05, 2.1, 2.15 (3s, 9H), 1.5 - 3.6 (complex m,
13 H), 3.8 (m, 1H), 4.0 (m, 1H), 4.6 (s, 2H), 7.0 (m, 2H), 7.5 (m, 8H).
Example 4
5-[4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione, hydrochloride:
[0154]

[0155] To a solution of 5-[4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione (300 mg) obtained in example 1 in Et
2O (15 ml) at 0°C., HCl gas was bubbled for 30 min. The resulting solution was stirred
for an additional 30 min; the supernatant liquid was decanted and the resulting solid
was washed with Et
2O (2 x 5 ml) and dried under reduced pressure over P
2O
5 for 6 h to get a pale yellow solid (200 mg, 75 %). mp. 212-214°C.
[α]
D27 = -25.5 (c, 0.4, CHCl
3).
1H NMR (DMSO-d
6, 200 MHz): δ 1.25,1.35 (2s, 3H), 1.99, 2.03, 2.12 (3s, 9H), 1.05 - 4.6 (complex m,
15H), 4.6,4.62 (2s, 2H), 7.0 - 7.7 (m, 9H), 7.8 (s, 1H), 9.6 (bs, 1H, exchangeable
with D
20).
Example 5
5-[4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione:
[0156]

Method A:
[0157] To a stirred suspension of the product obtained in example 1 (0.5 g) in methanol
(20 ml) at room temperature was added magnesium turnings (0.36 g) and the reaction
mixture was stirred at the same temperature for 1.5 h. The reaction mixture was added
to ice water (10 ml), the pH was adjusted to 6.5 - 7.0 using 10 % aqueous hydrochloric
acid and the solution was extracted with chloroform (3 x 25 ml). The combined organic
extract was washed with H
2O, dried (CaCl
2) and the solvent was removed under reduced pressure. The residual mass was chromatographed
on silica gel using 0.5 % methanol in chloroform to give 0.46 g (92 %) of the title
compound, mp: 62 - 64°C.
Method B:
[0158] A mixture of ethyl 2-bromo-3-[4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl]propanoate
(7 g), obtained in preparation 29, thiourea (1.6 g), NaOAc (1.73 g) and EtOH (42 ml)
was stirred under reflux for 5 h. The reaction mixture was cooled and extracted with
EtOAc, dried (Na
2SO
4) and concentrated to get 2-imino-5-[4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]benzyl]-4-thiazolidinone
which was used in the next step without further purification.
[0159] A mixture of the above crude product, 2N HCl (60 ml) and EtOH (60 ml) was stirred
under reflux for 12 h. The reaction mixture was concentrated in vacuo. The residue
was diluted with water, neutralized with saturated aqueous NaHCO
3 and extracted with ethyl acetate. The EtOAc extract was washed with brine, dried
(Na
2SO
4) and concentrated in vacuo. The residue was chromatographed on silica gel with 40
% EtOAc in pet. ether as eluent to afford the title compound (5.5 g, 85 %) as a fluffy
solid, mp 62 - 64°C.
[α]
D27 = -26.4 (c, 1.0, CHCl
3).
1H NMR (CDCl
3, 200 MHz): δ 1.25 (m, 3H), 1.5 - 2.05 (m, 6H), 2.1 - 2.2 (m, 9H), 2.3 - 3.25 (m,
7H), 3.4 (m, 2H), 3.75 (m, 1H), 3.95 (m, 1H), 4.5 (m, 1H), 4.7 (s, 2H), 6.8 (m, 2H),
7.15 (m, 2H), 7.3 - 7.6 (m, 5H).
Example 6
5-[4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione, Maleate:
[0160]

[0161] The title compound (0.28 g, 94 %) was prepared as a pale yellow solid from 5-[4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione (0.25 g), obtained in example 5 by an analogous procedure
to that described in example 2, mp: 180°C.
[α]
D27 = 19.4 (c, 0.66, CHCl
3).
1H NMR (CDCl
3, 200 MHz): δ 1.2, 1.25 (2s, 3H), 2.0, 2.05, 2.1 (3s, 9H), 1.5 - 4.5 (complex m, 17H),
4.6 (s, 2H), 4.9 (m, 1H), 6.1 (s, 2H), 6.9 (m, 2H), 7.2 (m, 2H), 7.5 (m, 5H), 12.1
(bs, 1H, exchangeable with D
2O).
Example 7
5-[4-[N-(2RS)-6-Benzyloxy-2,5,7,8,-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione, sodium salt:
[0162]

[0163] The title compound (0.27 g, 75 %) was prepared as a white solid from 5-[4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl] thiazolidine-2,4-dione (0.35 g), obtained in example 5, by an analogous procedure
to that described in example 3, mp : 191°C.
[α]
D27 = -23.1 (c, 1.0, CHCl
3).
1H NMR (CDCl
3, 200 MHz): δ 1.5, 1.25 (2s, 3H), 2.0 (s, 3H), 2.1 (s, 6H), 1.4-4.0 (complex m, 17H),
4.1 (m, 1H), 4.6 (s, 2H), 6.8 (m, 2H), 7.1 (m, 2H), 7.5 (m, 5H).
Example 8
5-[4-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione, Hydrochloride:
[0164]

[0165] The title compound (0.18 g, 86 %) was prepared as a pale yellow solid from 5-[4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl] thiazolidine-2,4-dione (0.2 g), obtained in example 5, by an analogous procedure
to that described in example 4, mp: 230°C.
[α]
D27 = -9.5 (c, 1.0, CHCl
3).
1H NMR (CDCl
3, 200 MHz): δ 1.30, 1.4 (2s, 3H), 2.0, 2.05, 2.2 (3s, 9H), 1.5 - 4.5 (complex m, 17H),
4.6 (s, 2H), 4.9 (m, 1H), 6.9 (m, 2H), 7.2 (m, 2H), 7.5 (m, 5H), 9.8 (bs, 1H, exchangeable
with D
2O), 12.1 (bs, 1H, exchangeable with D
2O).
Example 9
a) 5-[3-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione (9a):
[0166]
and
b) 5-[3-[N-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(3R)-piperidinyloxy]phenyl
methylene]thiazolidine-2,4-dione (9b):
[0167]

[0168] The title compounds
9a and
9b (4.5 g, 94 %) were prepared from the crude mixture obtained in preparation 15, by
a similar procedure to that described in example 1 and the crude product was separated
by column chromatography on silica gel using 0.5 % methanol in chloroform to afford
9a (1.5 g, 31 %, gummy solid) and
9b (2.0 g, 42 %, gummy solid).
9a: 1H NMR (CDCl
3, 200 MHz): δ 1.21,1.27 (2s, 3H), 1.5 - 2.05 (m, 6H), 2.05 - 2.2 (m, 9H), 2.3 - 3.2
(m, 6H), 3.4 (m, 1H), 3.8 (m, 1H), 4.05 (m, 1H), 4.7 (s, 2H), 7.0 (m, 4H), 7.25 -
7.6 (m, 5H), 7.77,7.81 (2s, 1H).
9b: 1H NMR (CDCl
3, 200 MHz): δ 1.21 (s, 3H), 1.3 - 2.8 (m, 12H), 1.91 (s, 3H), 2.16 (s, 6H), 3.1 (m,
1H), 3.55 (m, 1H), 4.4 (m, 1H), 4.7 (s, 2H), 6.85 - 7.55 (m, 9H), 7.78 (s, 1H).
Example 10
5-[4-[N-(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(3R)-piperidinyloxy]
phenyl methylene]thiazolidine-2,4-dione:
[0169]

[0170] The title compound (1 g, 57 %) was prepared as a pale yellow solid from 4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(3R)-piperidinyloxy]benzaldehyde
(
14b, 1.5 g), obtained in preparation 14 by a similar procedure to that described in example
1. mp: 142°C.
1H NMR (CDCl
3, 200 MHz): δ 1.22 (s, 3H), 1.3 - 1.90 (m, 6H), 2.0 (s, 3H), 2.19 (s, 6H), 1.95-2.8
(m, 6H), 2.9 (m, 1H), 3.25 (m, 1H), 4.4 (m, 1H), 4.69 (s, 2H), 6.95 (m, 2H), 7.3 -
7.6 (m, 7H), 7.78 (s, 1H).
Example 11
5-[4-[N-(5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-(R or S)-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione:
[0171]

[0172] The title compound (0.8 g, 67 %) was prepared as a pale yellow solid from 4-[N-[(3R/S)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]benzaldehyde
(1.0 g) obtained from preparation 16 by a similar procedure to that described in example
1, mp 68 - 70°C.
[α]
D24 = -201.5 (c, 1.0, CHCl
3).
1H NMR (CDCl
3, 200 MHz): δ 1.32 (s, 3H), 1.58 (s, 3H), 1.82 (m, 4H), 2.08 (s, 3H), 2.18 (s, 3H),
2.25 (s, 3H), 2.42 (m, 2H), 2.76 (m, 1H), 3.14 (m, 2H), 3.35 (m, 1H), 3.84 (m, 1H),
4.02 (m, 1H), 4.71 (s, 2H), 6.95 (d, J = 8.7 Hz, 2H), 7.45 (m, 7H), 7.80 (s, 1H).
Example 12
5-[4-[N-[(3RS)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(3R)-piperidinyloxy]phenyl
methylene]thiazolidine-2,4-dione (12):
[0173]

[0174] The title compound (0.75 g, 42 %) was prepared as a pale yellow solid from the crude
mixture (1.5 g) obtained in preparation 16 in a similar manner to that described in
example 1. The crude product was chromatographed on silica gel to get
12. mp 150 -152°C.
[α]
D24 = + 87.1 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1. 13, 1.37 (2s, 3H), 1.43 - 1.69 (complex m, 5H), 1.88 (m, 2H), 2.09
(s, 3H), 2.11 (s, 3H), 2.19 (s, 3H), 2.36 (m, 2H), 2.63 (m, 2H), 2.91 (m, 1H), 3.09
(m, 2H), 4.42 (m, 1H), 4.71 (s, 2H), 6.95 (m, 2H), 7.45 (m, 7H), 7.81 (s, 1H).
Example 13
5-[4-[N-[3(RS)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione maleate:
[0175]

[0176] The title compound (0.11 g, 92 %) was prepared as a yellow solid from 5-[4-[N-[(3R/S)-5-
benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione (0. 1 g) obtained in example 11 by an analogous procedure
to that described in example 2, mp : 158 - 161°C.
1H NMR (CDCl
3, 200 MHz): δ 1.37 (s, 3H), 1.63 (s, 3H), 1.95 (m, 4H), 2.10 (s, 3H), 2.22 (s, 3H),
2.27 (s, 3H), 2.63 (m, 2H), 3.16 (m, 1H), 3.30 (m, 2H), 3.52 (m, 1H), 3.85 (m, 1H),
4.03 (m, 1H), 4.72 (s, 2H), 6.28 (s, 2H), 7.03 (d, J = 8.4 Hz, 2H), 7.48 (m, 7H),
7.79 (s, 1H).
Example 14
5-[4-[N-[(3R/S)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione, Hydrochloride:
[0177]

[0178] The title compound (0.27 g, 85 %) was prepared as a colorless solid from 5-[4-[N-(3R/S)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]
phenyl methylene]thiazolidine-2,4-dione (0.3 g) obtained in example 11 by an analogous
procedure to that described in example 4, mp : 218 - 224°C.
1H NMR (CDCl
3, 200 MHz): δ 1.45 (s, 3H),1.60 (s, 3H), 1.80 (m, 4H), 2.08 (s, 3H), 2.19 (s, 3H),
2.26 (s, 3H), 2.50 (m, 2H), 2.90 (m, 1H), 3.25 (m, 2H), 3.40 (m, 1H), 4.12 (m, 1H),
4.30 (m, 1H), 4.71 (s, 2H), 7.08 (d, J = 8.6 Hz, 2H), 7.49 (m, 7H), 7.76 (s, 1H).
Example 15
a) 5-[4-[N-[(3RS)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione (15a):
[0179]
and
b) 5-[4-[N-[(3RS)-2,3-Dihydro-5-hydroxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione (15b):
[0180]

[0181] The title compounds
15a and
15b were prepared from ethyl 2-bromo-3-[4-[N-[(3RS)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]
phenyl]propanoate (2.5 g) obtained in preparation 31 by a similar procedure to that
described in method B of example 5. The crude compound was chromatographed on silica
gel to get
15a as a colorless fluffy solid (1.74 g, 75 %) and
15b as a fluffy solid (0.4 g, 20 %)
15a : mp: 107 - 109°C.
[α]
D29 = - 79.5 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.30,1.34 (2s, 3H), 1.57,1.60 (2s, 3H), 1.79 (m, 4H), 2.09 (s, 3H),
2.19 (s, 3H), 2.26 (s, 3H), 2.45 (m, 2H), 2.78 (m, 1H), 3.03 (m, 1H), 3.14 (m, 2H),
3.38 (m, 1H), 3.55 (m, 1H), 3.74 (m, 1H), 3.98 (m, 1H), 4.46 (m, 1H), 4.70 (m, 2H),
6.78 (m, 2H), 7.10 (m, 2H), 7.42 (m, 5H).
15b : mp. 72 - 75°C.
[α]
D29 = - 84.2 (c, 1.0, CHCl
3).
1H NMR (CDCl
3, 200 MHz): δ 1.26,1.30 (2s, 3H), 1.53,1.58 (2s, 3H), 1.78 (m, 4H), 2.08 (s, 3H),
2.11 (s, 3H), 2.17, 2.20 (2s, 3H), 2.36 (m, 2H), 2.72 (m, 1H), 2.98 (m, 1H), 3.13
(m, 2H), 3.45 (m, 2H), 3.75 (m, 1H), 3.98 (m, 1H), 4.19 (s, 1H), 4.50 (dd, J = 9.4,
3.8 Hz, 1H), 6.76 (m, 2H), 7.12 (m, 2H).
Example 16
5-[4-[N-[(3RS)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione, maleate:
[0182]

[0183] The title compound (0.44 g, 79 %) was prepared as a pale yellow solid from 5-[4-[N-[(RS)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethyl]benzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione (15a, 0.47 g), obtained in example 15 by an analogous
procedure to that described in example 2, mp. 179-182°C.
[α]
D25 = -53.4 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.36, 1.40 (2s, 3H), 1.62, 1.67 (2s, 3H), 2.06 - 2.45 (complex m, 15H),
2.81 (m, 1H), 3.14 - 3.64 (complex m, 5H), 4.16 - 4.21 (complex m, 2H), 4.50 (m, 1H),
4.64 - 4.72 (m, 2H), 6.27 (s, 2H), 6.82 (m, 2H), 7.17 (m, 2H), 7.43 (m, 5H).
Example 17
5-[4-[N-[(3RS)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethyl benzofuran-3-ylmethyl-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione hydrochloride:
[0184]

[0185] The title compound (0.4 g, 76 %) was prepared as a colorless solid from 5-[4-[(3RS)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethyl]benzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione (15a, 0.5 g) obtained in example 15 by an analogous
procedure to that described in example 4, mp 161-163°C.
[α]
D25 = -2.4 (c, 1.0, CHCl
3).
1H NMR (CDCl
3, 200 MHz): δ 1.35 (s, 3H), 1.66 (s, 3H), 1.85 - 2.27 (complex m, 15 H), 3.02 -3.96
(complex m, 6H), 4.22 - 4.37 (m, 2H), 4.63 (m, 2H), 4.86 (m, 1H), 6.95 (d, J = 7.8
Hz, 2H), 7.22 (d, J = 7.8 Hz, 2H), 7.45 (m, 5H), 9.96 (bs, 1H, exchangeable with D
2O), 12.05 (s, 1H, exchangeable with D
2O).
Example 18
5-[4-[N-[(3RS)-2,3-dihydro-5-hydroxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione, hydrochloride:
[0186]

[0187] The title compound (0.32 g, 75 %) was prepared as a colorless solid from 5-[4-[N-[(3RS)-2,3-dihydro-5-hydroxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]
phenyl methyl]thiazolidine-2,4-dione (15b, 0.4 g) obtained in example 15 by an analogous
procedure to that described in example 4, mp 193-195°C.
[α]
D25 = -53.9 (c, 1.0, CHCl
3).
1H NMR (CDCl
3, 200 MHz): δ 1.30 (s, 3H), 1.63 (s, 3H), 1.77 - 2.28 (complex m, 15 H), 3.03 - 3.38
(complex m, 6H), 4.21 (m, 1H), 4.42 (m, 1H), 4.90 (dd, J = 8.72,4.19 Hz, 1H), 6.94
(d, J = 8.2, 2H), 7.22 (d, J = 7.9 Hz, 2H), 9.86 (bs, 1H, exchangeable with H
2O), 12.06 (s, 1H, exchangeable with D
2O).
Example 19
5-[3-[N-[(3RS)-5-Benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione:
[0188]

[0189] The title compound (0.3 g, 51 %) was prepared from 3-[N-(5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]benzaldehyde
(0.5 g) obtained in, preparation 17 by a similar procedure to that described in example
1. mp 58 - 60°C.
[α]
D23 = -96.7 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.33 (s, 3H), 1.60 (s, 3H), 1.92 (m, 4H), 2.08 (s, 3H), 2.19, (s, 3H),
2.26 (s, 3H), 2.45 (m, 2H), 2.78 (m, 1H), 3.14 (m, 2H), 3.38 (m, 1H), 3.82 (m, 1H),
4.02 (m, 1H), 4.71 (s, 2H), 6.94 (m, 2H), 7.07 (d, J = 7.8 Hz, 1H), 7.45 (m, 6H),
7.80 (s, 1H).
Example 20
5-[4-[N-(5-Benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione:
[0190]

[0191] The title compound (0.4 g, 56 %) was prepared from 4-[N-(5-benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]benzaldehyde
(
18a, 0.6 g) obtained in preparation 18 by an analogous procedure to that described in
example 1, mp. 180 -183°C.
1H NMR (CDCl
3, 200 MHz): δ 1.75 (m, 4H), 2.05 (m, 1H), 2.31 (s, 3H), 2.38 (s, 3H), 2.42 (s, 3H),
2.60 (s, 3H), 3.00 (m, 2H), 3.63 (d, J = 12.9 Hz, 1H), 3.78 (m, 1H), 3.83 (m, 1H),
4.04 (d, J = 12.9 Hz, 1H), 4.71 (s, 2H), 6.78 (d, J = 8.6 Hz, 2H), 7.44 (m, 7H), 7.78
(s, 1H).
Example 21
5-[4-[N-(5-Benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione sodium salt:
[0192]

[0193] The title compound (0.28 g, 67 %) was prepared as a pale yellow solid from 5-[4-[N-[5-benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione (0.4 g) obtained in example 20 by an analogous procedure
to that in example 3, mp. 210 - 218°C.
[α]
D25 = + 65.1 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.68 (m, 4H), 2.01 (m, 1H), 2.23 (s, 3H), 2.30 (s, 3H), 2.40 (s, 3H),
2.59 (s, 3H), 2.88 (m, 2H), 3.46 (d, J = 12.8 Hz, 1H), 3.90 (m, 2H), 4.12 (d, J=12.9
Hz, 1H), 4.62 (s, 2H), 6.86 (d, J = 8.7 Hz, 2H), 7.41 (m, 8H).
Example 22
5-[4-[N-(5-Benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(3R)-piperidinyloxy]
phenyl methylene]thiazolidine-2,4-dione:
[0194]

[0195] The title compound (0.9 g, 75 %) was prepared as a yellow solid from 4-[N-(5-benzyloxy-2,4,6,7-tetramemylbenzofuran-3-ylmemyl)-(3R)-piperidinyloxy]benzaldehyde
(
18b, 1.0 g) obtained in preparation 18 by a similar procedure as described in example
1, mp 100 -103°C.
[α]
D20 = -52.4 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.58 (m, 3H), 1.78 (m, 1H), 2.16 (s, 2H), 2.33 (s, 3H), 2.40 (s, 6H),
2.73 (s, 3H), 2.78 (m, 1H), 3.15 (m, 1H), 3.48 (d, J = 4.9 Hz, 2H), 4.34 (m, 1H),
4.77 (s, 2H), 6.91 (d, J = 8.7 Hz, 2H), 7.42 (m, 7H), 7.74 (s, 1H).
Example 23
5-[4-[N-(5-Benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione:
[0196]

[0197] The title compound (0.4 g, 20 %) was prepared as a colorless solid from ethyl 2-bromo-3-[4-[N-(5-benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl]
propanoate (2.25 g) obtained in preparation 32 by an analogous procedure to that described
in method B of example 5. mp, 55 - 57°C.
[α]
D25 = + 25.2 (c, 0.5, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.75 (m, 4H), 2.05 (m, 1H), 2.30 (s, 3H), 2.37 (s, 3H), 2.41 (s, 3H),
2.60 (s, 3H), 2.98 (m, 2H), 3.10 (m, 1H), 3.41 (m, 1H), 3.55 (m, 1H), 3.72 (m, 1H),
3.90 (m, 1H), 4.12 (m, 1H), 4.45 (m, 1H), 4.74 (s, 2H), 6.70 (m, 2H), 7.04 (d, J =
7 Hz, 2H), 7.42 (m, 5H).
Example 24
5-[4-[N-(5-Benzyloxy-2-methylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione:
[0198]

[0199] The title compound (0.4 g, 73 %) was prepared as a pale yellow solid from 4-[N-[5-benzyloxy-2-methylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]benzaldehyde
(0.45 g) obtained in preparation 19 by a similar procedure to that described in example
1.
[α]
D24 = -12.2 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.75 (m, 3H), 1.93 (m, 2H), 2.46 (s, 3H), 3.12 (m, 2H), 3.89 (d, J =
14.1 Hz, 1H), 4.05 (m, 1H), 4.13 (m, 1H), 4.19 (d, J = 14.1 Hz, 1H), 4.92 (s, 2H),
6.87 (m, 1H), 6.94 (d, J = 8.9 Hz, 2H), 7.13 (d, J = 2.2 Hz, 1H), 7.36 (m, 8H), 7.55
(s, 1H).
Example 25
4-[N-[5-Benzyloxy-2-methylbenzofuran-3-ylmethyl]-(3R)-piperidinyloxy]phenyl methylene]
thiazolidine-2,4-dione (25):
[0200]

[0201] The title compound (1.5 g, 41 %) was prepared as a yellow solid from the crude mixture
(3 g) obtained in preparation 19 by a similar procedure to that described in example
1. The crude product was chromatographed on silica gel to get
25, mp 150-155°C.
[α]
D30 = -7.8 (c, 1.0, CHCl
3).
1H NMR (CDCl
3, 200 Mhz) : δ 1.33 (m, 2H), 1.84 (m, 1H), 1.92 -2.28 (complex m, 3H), 2.39 (s, 3H),
2.76 (m, 1H), 3.08 (m, 1H), 3.62 (d, J = 2.5 Hz, 2H), 4.35 (m, 1H), 5.09 (s, 2H),
6.89 (m, 3H), 7.35 (m, 9H), 7.73 (s, 1H).
Example 26
5-[4-[N-(5-Benzyloxy-2-methylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methyl]thiazolidine-2,4-dione:
[0202]

[0203] The title compound (0.7 g, 54 %) was prepared as a colorless solid from 5-[4-[N-(5-benzyloxy-2-methylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione (1.3 g) obtained in example 24, by an analogous procedure
to that described in method A of example 5. mp : 68 - 71 °C.
[α]
D25 = -11.6 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.76 (m, 4H), 2.05 (m, 1H), 2.41 (s, 3H), 3.05 (m, 3H), 3.34 (m, 1H),
3.64 (m, 1H), 3.96 (m, 2H), 4.19 (m, 1H), 4.36 (dd, J = 8.5,3.1 Hz, 1H), 4.89 (s,
2H), 6.84 (m, 3H), 7.14 (m, 3H), 7.35 (m, 6H).
Example 27
5-[4-[N-(1-Methylindol-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl methylene]thiazolidine-2,4-dione:
[0204]

[0205] The title compound (0.35 g, 27 %) was prepared from 4-[N-(l-methylindol-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]benzaldehyde
(1.02 g) obtained in preparation 20, by a similar procedure to that described in example
1. mp 159 - 160°C.
[α]
D26 = - 42.49 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.89 (m, 2H), 2.17 (m, 2H), 2.96 (m, 1H), 3.49 (m, 1H), 3.75 (m, 1H),
3.86 (s, 3H), 4.28 (m, 2H), 4.53 (d, J = 5.3 Hz, 2H), 6.89 (d, J = 8.0 Hz, 2H), 7.28
(m, 7H), 7.75 (d, J = 6.6 Hz, 1H).
Example 28
5-[4-[2-[4-[(2RS)-6-Benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]piperazine-1-yl]ethoxy]phenyl
methylene]thiazolidine-2,4-dione:
[0206]

[0207] The title compound (0.16 g, 67 %) was prepared as a pale yellow solid from 4-[2-[4-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl)piperazine-1-yl]ethoxy]benzaldehyde,
(0.2 g) obtained in preparation 21 by a similar procedure to that described in example
1. mp 192-194°C.
1H NMR (CDCl
3, 200 MHz): δ 1.24 (s, 3H), 1.7 (m, 1H), 2.0 (m, 1H), 2.07 (s, 3H), 2.17 (s, 3H),
2.22 (s, 3H), 2.45 - 3.0 (m, 14H), 4.2 (bs, 2H), 4.7 (s, 2H), 6.88 (d, J = 8.8 Hz,
2H), 7.2 - 7.6 (m, 7H).
Example 29
5-[4-[2-[4-(1-Methylindol-3-ylmethyl)piperazin-1-yl]ethoxy]phenyl methylene]thiazolidine-2,4-dione:
[0208]

[0209] The title compound (0.7 g, 84 %) was prepared as a pale yellow solid from 4-[2-[4-[(1-methylindol-3-ylmethyl)piperazin-1-yl]ethoxy]benzaldehyde
(0.6 g) obtained in preparation 22, by a similar procedure to that described in example
1. mp 183 - 188°C.
1H NMR (CDCl
3+CD
3OD, 200 MHz): δ 2.69 (bs, 8H), 2.86 (t, J = 5.4 Hz, 2H), 3.81 (s, 5H), 4.17 (t, J
= 5.21 Hz, 2H), 6.99 (d, J = 8.72 Hz, 2H), 7.19 (m, 4H), 7.48 (m, 2H), 7.70 (m, 2H).
Example 30
5-[4-[N-[(2RS)-6-Hydroxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]
phenyl methylene]thiazolidine-2,4-dione:
[0210]

[0211] To a solution of 0.5 g of the product obtained in example 1, in 6 ml of acetic acid
(6 ml) was added concentrated hydrochloric acid (2 ml). The resulting mixture was
heated at 60°C. for 2 h. At the end of this time, the solvent was removed under reduced
pressure and the residue was diluted with CHCl
3 and washed with aqueous sodium bicarbonate solution followed by brine. The organic
layer was dried over anhydrous calcium chloride and the solvent was removed by distillation
under reduced pressure. The crude product was purified by column chromatography on
silica gel using 0 to 1 % (gradient elution) methanol in chloroform to afford 0.42
g (98 %) of the title compound as a pale yellow solid. mp 82 - 84°C.
[α]
D27 = -29.44 (c, 0.9, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.21, 1.25 (2s, 3H), 1.5 - 2.05 (m, 6H), 2.13 (m, 9H), 2.3 - 3.2 (m,
6H), 3.4 (m, 1H), 3.9 (m, 1H), 4.05 (m, 1H), 6.95 (d, J = 7.4 Hz, 2H), 7.45 (m, 2H),
7.82, 7.83 (2s, 1H).
Example 31
5-[4-[N-[(2RS)-6-Hydroxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]
phenyl methyl]thiazolidine-2,4-dione:
[0212]

[0213] The title compound (0.22 g, 86 %) was prepared as a pale yellow solid from 5-[4-[N-[(2RS)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methyl] thiazolidine-2,4-dione (0.3 g), obtained in example 5 by an analogous procedure
to that described in example 30. mp. 76 - 78°C.
1H NMR (CDCl
3, 200 MHz): δ 1.21 (3s, 3H), 1.5 - 2.05 (m, 6H), 2.1 (s, 6H), 2.15 (s, 3H), 2.3 -
2.8 (m, 4H), 2.9 - 3.25 (m, 3H), 3.4 (m, 2H), 3.6 - 4.0 (m, 2H), 4.5 (dd, J = 8.8
Hz and 3.8 Hz), 6.8 (m, 2H), 7.12 (d, J = 8.2 Hz, 2H).
Example 32
5-[4-[N-[(3R/S)-5-Hydroxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione:
[0214]

[0215] The title compound (0.13 g, 43 %) was prepared as a yellow solid from 5-[4-[N-[(3R/S)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]
phenyl methylene]thiazolidine-2,4-dione (0.4 g) obtained in example 11, by an analogous
procedure to that described in example 30. mp 75 - 77°C.
[α]
D29 = -175.5 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.31 (s, 3H), 1.58 (s, 3H), 1.85 (m, 4H), 2.09 (s, 3H), 2.13 (s, 3H),
2.22 (s, 3H), 2.38 (m, 2H), 2.76 (m, 1H), 3.11 (m, 2H), 3.36, (m, 1H), 3.85 (dd, J
= 9.1 and 6.4 Hz, 1H), 4.06 (dd, J = 9.1 and 4.9 Hz, 1H), 4.16 (bs, 1H), 6.95 (d,
J = 8.7 Hz, 2H), 7.43 (d, J = 8.7 Hz, 2H), 7.8 (s, 1H).
Example 33
5-[4-[N-(5-Hydroxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione:
[0216]

[0217] The title compound (0.27 g, 45 %) was prepared from 5-[4-[N-(5-benzyloxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione (0.7 g) obtained in example 20, by an analogous procedure
to that described in example 30. mp, 157 - 158°C.
[α]
D26 = + 75.1 (c, 0.7, EtOAc)
1H NMR (CDCl
3, 200 MHz): δ 1.78 (m, 4H), 2.04 (m, 1H), 2.24 (s, 3H), 2.38 (s, 3H), 2.40 (s, 3H),
2.51 (s, 3H), 3.04 (m, 2H), 3.62 (d, J = 12.9 Hz, 1H), 3.79 (m, 1H), 3.83 (m, 1H),
4.04 (d, J = 12.9 Hz, 1H), 6.76 (d, J = 8.9 Hz, 2H), 7.38 (d, J = 8.7 Hz, 2H), 7.78
(s, 1H).
Example 34
5-[4-[N-(5-Hydroxy-2,4,6,7-tetramethylbenzofuran-3-ylmethyl)-(3R)-piperidinyloxy]
phenylmethylene]thiazolidine-2,4-dione:
[0218]

[0219] The title compound (0.1 g, 47 %) was prepared from 4-[N-(5-benzyloxy-2,4,6,7-tetramethyl-3-ylmethyl)-(3R)-piperidinyloxy]phenyl
methylene]thiazolidine-2,4-dione (0.25 g) obtained in example 22, by an analogous
procedure as described in example 30, mp. 192 - 195°C.
[α]
D20 = -36.3 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.45 (m, 3H), 1.90 (m, 1H), 2.09 (m, 2H), 2.24 (s, 3H), 2.33 (s, 3H),
2.35 (s, 3H) 2.65 (m, 1H), 3.05 (m, 1H), 3.48 (d, J = 3.1 Hz, 2H), 4.35 (m, 1H), 6.90
(d, J = 8.7 Hz, 2H), 7.37 (d, J = 8.7 Hz, 2H), 7.68 (s, 1H)
Example 35
5-[3-[N-[(3RS)-[2,3-Dihydro-5-hydroxy-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione:
[0220]

[0221] The title compound (0.68 g, 80 %) was prepared from 5-[3-[N-[(3RS)-5-benzyloxy-2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidine-2-methoxy]phenyl
methylene] thiazolidine-2,4-dione (1 g) obtained in example 19 by an analogous procedure
to that described in example 30, mp 70 - 72°C.
[α]
D23 = - 83.9 (c, 1.0, CHCl
3)
1H NMR (CDCl
3, 200 MHz): δ 1.31 (s, 3H), 1.59 (s, 3H), 1.85 (m, 4H), 2.08 (s, 3H), 2.12 (s, 3H),
2.21 (s, 3H), 2.35 (m, 2H), 2.78 (m, 1H), 3.14 (m, 2H), 3.38 (m, 1H), 3.84 (m, 1H),
4.04 (dd, J = 9.13 and 4.8 Hz, 1H), 4.19 (bs, 1H, exchangeable with D
2O), 6.96 (m, 2H), 7.06 (m, 1H), 7.34 (m, 1H), 7.79 (s, 1H).
Example 36
5-[4-[N-(5-Hydroxy-2-methylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxylphenyl
methylene]thiazolidine-2,4-dione:
[0222]

[0223] The title compound (0. 1 g, 40 %) was prepared from 5-[4-[N-(5-benzyloxy-2-methylbenzofuran-3-ylmethyl)-(2S)-pyrrolidine-2-methoxy]phenyl
methylene]thiazolidine-2,4-dione, (0.3 g) obtained, in example 24 by an analogous
procedure to that described in example 30, mp 206 - 208°C.
[α]
D25 = + 48.4 (c, 1.0, pyridine)
1H NMR (CDCl
3, 200 MHz): δ 1.75 (m, 2H), 1.77 (m, 2H), 2.02 (m, 1H), 2.43 (s, 3H), 3.08 (m, 1H),
3.21 (m, 1H), 3.75 (d, J = 13.61 Hz, 1H) 4.09 (m, 2H), 4.19 (d, J = 13.61 Hz, 1H),
6.79 (m, 1H), 6.95 (d, J = 8.7 Hz, 2H), 7.06 (m, 1H), 7.16 (m, 1H), 7.34 (d, J = 8.7
Hz, 2H), 7.59 (s, 1H).
[0224] Mutation in colonies of laboratory animals and different sensitivities to dietary
regimens have made the development of animal models with non-insulin dependent diabetes
associated with obesity and insulin resistance possible. Genetic models such as db/db
and ob/ob (See Diabetes, (1982) 31(1) : 1- 6) in mice and fa/fa and zucker rats have
been developed by the various laboratories for understanding the pathophysiology of
disease and testing the efficacy of new antidiabetic compounds (Diabetes, (1983) 32:
830-838 ; Annu. Rep. Sankyo Res. Lab. (1994). 46 : 1-57). The homozygous animals,
C57 BL/KsJ-db/db mice developed by Jackson Laboratory, US, are obese, hyperglycemic,
hyperinsulinemic and insulin resistant (J. Clin. Invest., (1990) 85 : 962-967), whereas
heterozygous are lean and normoglycemic. In db/db model, a mouse progressively develops
insulinopenia with age, a feature commonly observed in late stages of human type II
diabetes when blood sugar levels are insufficiently controlled. The state of pancreas
and its course vary according to the models. Since this model resembles that of type
II diabetes mellitus, the compounds of the present invention were tested for blood
sugar and triglycerides lowering activities.
[0225] The compounds of the present invention showed blood sugar and triglycerides lowering
activities through improved insulin resistance. This was demonstrated by the following
in vivo experiments.
[0226] Male C57BL/KsJ-db/db mice of 8 to 14 weeks age, having body weight range of 35 to
60 grams, procured from the Jackson Laboraotory, USA, were used in the experiment.
The mice were provided with standard feed (National Institute of Nutrition, Hyderabad,
India) and acidified water, ad libitum. The animals having more than 300 mg / dl blood
sugar were used for testing. The number of animals in each group was 4.
[0227] The random blood sugar and triglyceride levels were measured by collecting blood
(100 µl) through orbital sinus, using heparinised capillary in tubes containing EDTA
which was centrifuged to obtain plasma. The plasma glucose and triglyceride levels
were measured spectrometrically, by glucose oxidase and glycerol-3-PO
4 oxidase/peroxidase enzyme (Dr. Reddy's Lab. Diagnostic Division Kits, Hyderabad,
India) methods respectively. On 6th day the blood samples were collected one hour
after administration of test compounds / vehicle for assessing the biological activity.
[0228] Test compounds were suspended on 0.25 % carboxymethyl cellulose and administered
to test group at a dose of 30 mg / kg through oral gavage daily for 6 days. The control
group received vehicle (dose 10 ml / kg). Troglitazone (100 mg / kg, daily dose) was
used as a standard drug which showed 28 % reduction in random blood sugar level on
6th day.
[0229] The blood sugar and triglycerides lowering activities of the test compound was calculated
according to the formula:
ZC = Zero day control group value
DC = Zero day treated group value
TC = Control group value on test day
DT = Treated group value on the test day
[0230] No adverse effects were observed for any of the mentioned compounds of invention
in the above test.
| Compound |
Reduction in Blood Glucose Level (%) |
Triglyceride Lowering (%) |
| Example 7 |
36 |
70 |
| Example 13 |
45 |
42 |
| Example 20 |
16 |
43 |
| Example 22 |
NA |
NA |
| NA = Not Active at dose of 30 mg/Kg but has activity at a higher dose. |
[0231] The experimental results from the db/db mice suggest that the novel compounds of
the present invention also possess therapeutic utility for prophylactic or regular
treatment of obesity, cardiovascular disorders such as hypertension, hyperlipidaemia
and other diseases; as it is known from the literature that such diseases are interrelated
to each other.