Field of the Invention
[0001] The invention provides new pharmaceutically active chemical compounds, which can
be used for treating conditions and disorders in animals, mammals, and humans.
Background
[0002] New chemical compounds having pharmaceutical activity can be indicated for the treatment
of previously untreatable conditions, better treatment of conditions than can be achieved
with conventional pharmaceutical compounds, and treatment of conditions that were
previously treatable with conventional pharmaceutical compounds, but now are no longer
effectively treatable. For example, such compounds can be useful in the case of bacterial
or viral infectious agents that have evolved to become drug resistant.
[0003] WO 92/06188 relates to quinuclidine derivatives and pharmaceutically acceptable salts thereof.
The compounds are said to be substance P antagonists and, therefore, are said to be
useful in treating gastrointestinal disorders, central nervous system disorders, inflammatory
diseases, pain and migraine.
[0004] WO2007/024814 relates to amide and urea derivatives of heteroaryl-substitued diazatricycloalkanes,
pharmaceutical compositions including the compounds, methods of preparing the compounds,
and methods of treatment using the compounds. More specifically, the methods of treatment
are said to involve modulating the activity of the α7 nAChR subtype by administering
one or more of the compounds to treat or prevent disorders mediated by α7 nAChR subtype.
The diazatricycloalkanes typically consist of a 1-azabicyclooctane fused to pyrrolidine
ring.
[0005] WO2008/l12734 relates to heterocyclic-carbonyl-diazabicycloalkanes as supposed modulators of the
neural nicotinic acetylcholine alpha-4 beta, subtype receptor for the treatment of
CNS related disorders.
SUMMARY OF THE INVENTION
[0006] The invention provides a compound of Formula 1:

1-(cyclopropylmethyl)-4-(3,3,3-trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridin-3-yl
pivalate, or a stereoisomer, pharmaceutically acceptable salt, or mixture thereof.
[0007] In certain embodiments, Formula 1 is

(2S,3S,6R,7aR)-1-(cyclopropylmethyl)-4-(3,3,3-trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridin-3-yl
pivalate.
[0008] In certain embodiments, the invention includes a pharmaceutical composition containing
a compound of Formula 1 and/or a derivative thereof. In one embodiment, the invention
includes a pharmaceutical composition comprising a compound of Formula 1 and/or derivative
thereof and a pharmaceutically acceptable carrier or diluent. In another embodiment,
the invention provides a method for treating a subject (a human or an animal) suffering
from a condition, disease, or disorder, comprising administering to the subject an
effective amount of a compound of Formula 1 and/or derivative thereof. In one embodiment,
the compound is administered to effect localized delivery to the subject. In another
embodiment, the compound is administered to effect systemic delivery to the subject.
In a further embodiment, a compound of Formula 1, and/or derivative thereof is used
as a medicament, or used in the manufacture of a medicament. In some embodiments,
the condition or disorder is neuropathic pain or chronic pain.
[0009] In other embodiments, the method includes making the compound of Formula 1. In one
such embodiment, the method of making the compound of Formula 1 includes reacting
a compound of Formula 2:

(2S*,3S*,3aS*,6R*,7aR*)-4-(3,3,3-trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridin-3-yl
pivalate with cyclopropylcarboxaldehyde in the presence of a reducing agent. In some
embodiments the cyclopropylcarboxaldehyde was added before the reducing agent. In
certain embodiments the reducing agent is sodium triacetoxyborohydride. In some embodiments
the compound of Formula 1 is chirally separated.
[0010] In some embodiments, the method can also include making the compound of Formula 2.
In an embodiment, the method of making the compound of Formula 2 includes reacting
a compound of Formula 3:

(2S*,3S*,3aS*,6R*,7aR*)-tert-butyl 3-(pivaloyloxy)-4-(3,3,3- trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate
with an acid. In certain embodiments, the acid is trifluoroacetic acid.
[0011] In some embodiments, the method can also include making the compound of Formula 3.
In an embodiment, the method of making the compound of Formula 3 includes reacting
a compound of Formula 4:

(2S*,3S*,3aS*,6R*,7aR*)-tert-butyl 3-hydroxy-4-(3,3,3- trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate
with dimethylaminopyridine (DMAP).
[0012] In some embodiments, the method can also include making the compound of Formula 4.
In an embodiment, the method of making the compound of Formula 4 includes reacting
a compound of Formula 5:

(2S*,3S*,3aS*,6R*,7aR*)-tert-butyl 3-((tertbutyldiphenylsilyl)oxy)-4-(3,3,3 trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate
with tert-butyldiphenylchlorosilane. In some embodiments the reaction further comprises
pyridine.
[0013] In some embodiments, the method can also include making the compound of Formula 5.
In an embodiment, the method of making the compound of Formula 5 includes reacting
a compound of Formula 6.b:

(2S*,3R*,3aS*,6R*,7aR*)-tert-butyl 3-((tertbutyldiphenylsilyl)oxy)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate
with 3,3,3-trifluoropropanoic acid. In some embodiments, the reaction further comprises
N-N-Diisopropylethylamine. In certain embodiments, the reaction further comprises
(1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophosphate)
sodium triacetoxyborohydride. In some embodiments, the method includes chirally separating
a compound of Formula 7:

rac-(2S*,3R*,3aS*,6R*,7aR*)-tert-butyl 3-((tertbutyldiphenylsilyl)oxy)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate.
[0014] In other embodiments, the method includes making the compound of Formula 7. In one
such embodiment, the method of making the compound of Formula 7 includes reacting
a compound of Formula 8:

rac-(2R,3R,6S,7aS)-tert-butyl 4-benzyl-3- ((tert-butyldiphenylsilyl)oxy)octahydro-1H-
2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate with hydrogen. The reaction may be
performed in the presence of a catalyst. In a preferred embodiment, the catalyst includes
palladium. For example, the catalyst can be palladium on carbon.
[0015] In other embodiments, the method includes making the compound of Formula 8. In one
such embodiment, the method of making the compound of Formula 8 includes reacting
a compound of Formula 9:

rac-(2R,3R,6S,7aS)-4-benzyl-3-((tert-butyldiphenylsilyl)oxy)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine
with di-tert-butyl dicarbonate (Boc
2O) to add a tert-butyloxycarbonyl (Boc) protecting group. In a preferred embodiment
the reaction further comprises triethylamine (Et
3N).
[0016] In other embodiments, the method also includes making the compound of Formula 9.
In one such embodiment, the method of making the compound of Formula 9 includes reacting
a compound of Formula 10:

(2R,3R,6S,7aS)-ethyl 4-benzyl-3-((tert-butyldiphenylsilyl)oxy)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate
with iodotrimethylsilane.
[0017] In other embodiments, the method also includes making the compound of Formula 10.
In one such embodiment, the method of making the compound of Formula 10 includes reacting
a compound of Formula 11:

(2R,3S,6S,7aS)-ethyl-4-benzyl-3-hydroxyoctahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate
with TBDPS. In a preferred embodiment the reaction further comprises imidazole.
[0018] In other embodiments, the method also includes making the compound of Formula 11.
In one such embodiment, the method of making the compound of Formula 11 includes reacting
a compound of Formula 12:

(2R,3S,6S,7aS)-ethyl 3-hydroxyoctahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate
with benzaldehyde. In a preferred embodiment the reaction further comprises sodium
triacetoxyborohydride (STAB).
[0019] In other embodiments, the method also includes making the compound of Formula 12.
In one such embodiment, the method of making the compound of Formula 12 includes cyclizing
a compound of Formula 12.a:

(1R,2R,4S,5S,7s)-ethyl 7-(aminomethyl)-3-oxa-9-azatricyclo[3.3.1.02,4]nonane-9-carboxylate
in a solvent. The solvent can be ethanol (EtOH).
[0020] In other embodiments, the method also includes making the compound of Formula 12.a.
In one such embodiment, the method of making the compound of Formula 12.a includes
reacting a compound of Formula 13:

(1R,2R,4S,5S,7s)-ethyl 7-cyano-3-oxa-9- azatricyclo[3.3.1.02,4]nonane-9-carboxylate
with hydrogen. The reaction may be performed in the presence of a catalyst. In one
embodiment, the catalyst includes nickel. For example, the catalyst can be Raney-nickel.
[0021] In other embodiments, the method also includes making the compound of Formula 13.
In one such embodiment, the method of making the compound of Formula 13 includes reacting
a compound of Formula 14:

(1R,2R,4S,5S,7r)-ethyl 7-((methylsulfonyl)oxy)-3-oxa-9-azatricyclo[3.3.1.02,4]nonane-9-carboxylate
with potassium cyanide. In other embodiments the reaction further comprises 18-crown-6
(1,4,7,10,13,16-hexaoxacyclooctadecane).
[0022] In other embodiments, the method also includes making the compound of Formula 14.
In one such embodiment, the method of making the compound of Formula 14 includes reacting
a compound of Formula 15:

(1R,2R,4S,5S,7r)-ethyl 7-hydroxy-3-oxa-9-azatricyclo[3.3.1.02,4]nonane-9-carboxylate
with mesyl chloride. In a preferred embodiment the reaction further comprises triethylamine
(ET
3N).
[0023] In other embodiments, the method also includes making the compound of Formula 15.
In one such embodiment, the method of making the compound of Formula 15 includes reacting
a compound of Formula 16:

(1R,2R,4S,5S,7r)-ethyl 7-(benzoyloxy)-3-oxa-9-azatricyclo[3.3.1.02,4]nonane-9-carboxylate
with a reducing agent. The reducing agent can be sodium borohydride.
[0024] In other embodiments, the method also includes making the compound of Formula 16.
In one such embodiment, the method of making the compound of Formula 16 includes reacting
a compound of Formula 17:

(1R,2R,4S,5S,7r)-9-methyl-3-oxa-9-azatricyclo[3.3.1.02,4]nonan-7-yl benzoate with
ethyl chloroformate. In a preferred embodiment the reaction further comprises a base.
The base can be potassium carbonate.
[0025] In other embodiments, the method also includes making the compound of Formula 17.
In one such embodiment, the method of making the compound of Formula 17 includes reacting
a compound of Formula 18:

(1R,2R,4S,5S)-9-methyl-3-oxa-9-azatricyclo[3.3.1.02,4]nonan-7-ol) with benzoic acid
in the presence of an activating agent. The activating agent can be diethylazodicaroxylate
(DEAD) with triphenylphosphine (PPh
3) or diisopropyl azodicarboxylate (DIAD) with PPh
3.
[0026] In other embodiments, the method also includes making the compound of Formula 18.
In one such embodiment, the method of making the compound of Formula 18 includes reacting
a compound of Formula 19:

(2S)-(1R,2R,4S,5S)-9-methyl-3-oxa-9-azatricyclo[3.3.1.02,4]nonan-7-yl-3-hydroxy-2-phenylpropanoate
hydrobromide trihydrate (scopolamine) with a reducing agent. The reducing agent can
be sodium borohydride. In a preferred embodiment the reaction further comprises HCl
in isopropyl alcohol.
[0027] In some embodiments, the compounds described herein are used in the treatment or
prevention of neuropathic pain in a subject in need. In other embodiments the compounds
described herein are useful in the treatment or prevention of chronic pain in a subject
in need.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The preceding Summary, as well as the following Detailed Description of the invention,
can be better understood when read in conjunction with the appended Figures. For the
purpose of illustrating the invention, the Figures demonstrate embodiments of the
present invention. However, it should be understood that the invention is not limited
to the precise arrangements, examples, and instrumentalities shown.
Figure 1 shows the results of a 1HNMR (CDCl3) analysis of the compound of Formula 18, according to one embodiment of the invention.
Figure 2 shows the results of a MS analysis of the compound of Formula 17, according
to one embodiment of the invention.
Figures 3A and 3B show the results of a structural analysis of the compound of Formula
16. Figure 3A shows the results of a 1HNMR analysis of the compound of Formula 16. Figure 3B shows the results of a MS analysis
of the compound of Formula 16.
Figure 4 shows the results of a 1HNMR analysis of the compound of Formula 15.
Figure 5 shows the results of a 1HNMR analysis of the compound of Formula 14.
Figure 6 shows the results of a 1HNMR analysis of the compound of Formula 13.
Figure 7 shows the results of a 1HNMR analysis of the compound of Formula 12.
Figures 8A and 8B show the results of a structural analysis of the compound of Formula
11. Figure 8A shows the results of a MS analysis of the compound of Formula 11. Figure
8B shows the results of a 1HNMR analysis of the compound of Formula 11.
Figures 9A and 9B show the results of a structural analysis of the compound of Formula
10. Figure 9A shows the results of a LCMS analysis of the compound of Formula 10.
Figure 9B shows the results of a 1HNMR analysis of the compound of Formula 10.
Figure 10 shows the results of a LCMS analysis of the compound of Formula 9.
Figures 11A and 11B show the results of a structural analysis of the compound of Formula
8. Figure 11A shows the results of a 1HNMR analysis of the compound of Formula 8. Figure 11B shows the results of a LCMS
analysis of the compound of Formula 8.
Figures 12A and 12B show the results of a structural analysis of the compound of Formula
7. Figure 12A shows the results of a LCMS analysis of the compound of Formula 7. Figure
12B shows the results of a 1HNMR analysis of the compound of Formula 7.
Figure 13 shows the results of a 1HNMR analysis of the compound of Formula 2.
Detailed Description
[0029] Embodiments of the invention are discussed in detail below. In describing these embodiments,
specific terminology is employed for the sake of clarity. However, the invention is
not intended to be limited to the specific terminology selected.
Certain Definitions
[0030] The term "alkyl" refers to branched or unbranched hydrocarbon chains, in for example,
hydrocarbon chains having from 1 to 12 carbon atoms in the chain. In some embodiments,
an alkyl group is a C
1-C
6 alkyl group. In some embodiments, an alkyl group is a C
1-C
4 alkyl group. Examples of alkyl groups include methyl (Me) ethyl (Et), n-propyl, isopropyl,
butyl, isobutyl, sec-butyl, tert-butyl (tBu), pentyl, isopentyl, tert-pentyl, hexyl,
isohexyl, and groups that in light of the ordinary skill in the art and the teachings
provided herein would be considered equivalent to any one of the foregoing examples.
[0031] The term "haloalkyl" refers to a straight- or branched-chain alkyl group having from
1 to 12 carbon atoms in the chain and having at least one of the hydrogens replaced
with a halogen. In some embodiments, a haloalkyl group is a C
1-C
6 haloalkyl group. In some embodiments, a haloalkyl group is a C
1-C
4 haloalkyl group. One exemplary substitutent is fluoro. Preferred substituted alkyl
groups of the invention include trihalogenated alkyl groups such as trifluoromethyl
groups. Haloalkyl includes and is not limited to CF
3, CH
2F, -CHF
2, -CH
2Cl, - CH
2-CF
3, and the like.
[0032] "Cycloalkyl" refers to monocyclic, non-aromatic hydrocarbon groups having from 3
to 7 carbon atoms. Examples of cycloalkyl groups include, for example, cyclopropyl,
cyclobutyl, cyclopentyl, cyclohexyl, and the like.
[0033] The term "alkoxy" includes a straight chain or branched alkyl group with a terminal
oxygen linking the alkyl group to the rest of the molecule. In some embodiments, an
alkoxy group is a C
1-C
6 alkoxy group. In some embodiments, an alkoxy group is a C
1-C
4 alkoxy group. Alkoxy includes methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy,
pentoxy and so on.
[0034] The term "heterocycle" represents" a mono- or bi-cyclic hydrocarbon ring structure
optionally containing heteroatoms selected from O, S, and N. Heterocyclyl rings can
have 2 to 10 carbon atoms in the ring.
[0035] The term "halogen" represents chlorine, fluorine, bromine, or iodine. The term "halo"
represents chloro, fluoro, bromo, or iodo.
[0036] A wavy line "

" indicates the point of attachment to the rest of the molecule.
[0037] "Benzyl" and -CH
2-phenyl are used interchangeably.
[0038] "Pharmaceutically acceptable" means approved or approvable by a regulatory agency
of the Federal or a state government or the corresponding agency in countries other
than the United States, or that is listed in the U.S. Pharmacopoeia or other generally
recognized pharmacopoeia for use in animals, and more particularly, in humans.
[0039] "Pharmaceutically acceptable salt" refers to a salt of a compound of the invention
that is pharmaceutically acceptable and that possesses the desired pharmacological
activity of the parent compound. In particular, such salts are non-toxic may be inorganic
or organic acid addition salts and base addition salts. Specifically, such salts include:
(1) acid addition salts, formed with inorganic acids such as hydrochloric acid, hydrobromic
acid, sulfuric acid, nitric acid, phosphoric acid, and the like; or formed with organic
acids such as acetic acid, propionic acid, hexanoic acid, cyclopentanepropionic acid,
glycolic acid, pyruvic acid, lactic acid, malonic acid, succinic acid, malic acid,
maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, 3-(4-hydroxybenzoyl)benzoic
acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, 1,2-ethane-disulfonic
acid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid, 4-chlorobenzenesulfonic
acid, 2-naphthalenesulfonic acid, 4-toluenesulfonic acid, camphorsulfonic acid, 4-methylbicyclo[2.2.2]-oct-2-ene-1-carboxylic
acid, glucoheptonic acid, 3-phenylpropionic acid, trimethylacetic acid, tertiary butylacetic
acid, lauryl sulfuric acid, gluconic acid, glutamic acid, hydroxynaphthoic acid, salicylic
acid, stearic acid, muconic acid, and the like; or (2) salts formed when an acidic
proton present in the parent compound either is replaced by a metal ion, e.g., an
alkali metal ion, an alkaline earth ion, or an aluminum ion; or coordinates with an
organic base such as ethanolamine, diethanolamine, triethanolamine, N-methylglucamine
and the like. Salts further include, by way of example only, sodium, potassium, calcium,
magnesium, ammonium, tetraalkylammonium, and the like; and when the compound contains
a basic functionality, salts of non-toxic organic or inorganic acids, such as hydrochloride,
hydrobromide, tartrate, mesylate, acetate, maleate, oxalate and the like.
[0040] "Pharmaceutically acceptable vehicle" refers to a diluent, adjuvant, excipient or
carrier with which a compound of the invention is administered. A "pharmaceutically
acceptable excipient" refers to a substance that is non-toxic, biologically tolerable,
and otherwise biologically suitable for administration to a subject, such as an inert
substance, added to a pharmacological composition or otherwise used as a vehicle,
carrier, or diluent to facilitate administration of a agent and that is compatible
therewith. Examples of excipients include calcium carbonate, calcium phosphate, various
sugars and types of starch, cellulose derivatives, gelatin, vegetable oils, and polyethylene
glycols.
[0041] "Subject" includes humans. The terms "human," "patient," and "subject" are used interchangeably
herein.
[0042] "Treating" or "treatment" of any disease or disorder refers, in one embodiment, to
ameliorating the disease or disorder (i.e., arresting or reducing the development
of the disease or at least one of the clinical symptoms thereof). In another embodiment
"treating" or "treatment" refers to ameliorating at least one physical parameter,
which may not be discernible by the subject. In yet another embodiment, "treating"
or "treatment" refers to modulating the disease or disorder, either physically, (e.g.,
stabilization of a discernible symptom), physiologically, (e.g., stabilization of
a physical parameter), or both. In yet another embodiment, "treating" or "treatment"
refers to delaying the onset of the disease or disorder.
[0043] In treatment methods according to the invention, a therapeutically effective amount
of a pharmaceutical agent according to the invention is administered to a subject
suffering from or diagnosed as having such a disease, disorder, or condition. A "therapeutically
effective amount" means an amount or dose sufficient to generally bring about the
desired therapeutic or prophylactic benefit in patients in need of such treatment
for the designated disease, disorder, or condition.
[0044] Effective amounts or doses of the compounds of the present invention may be ascertained
by routine methods such as modeling, dose escalation studies or clinical trials, and
by taking into consideration routine factors, e.g., the mode or route of administration
or drug delivery, the pharmacokinetics of the compound, the severity and course of
the disease, disorder, or condition, the subject's previous or ongoing therapy, the
subject's health status and response to drugs, and the judgment of the treating physician.
An example of a dose is in the range of from about 0.001 to about 200 mg of compound
per kg of subject's body weight per day, preferably about 0.05 to 100 mg/kg/day, or
about 1 to 35 mg/kg/day, in single or divided dosage units (e.g., BID, TID, QID).
For a 70-kg human, an illustrative range for a suitable dosage amount is from about
0.05 to about 7 g/day, or about 0.2 to about 2.5 g/day.
[0045] "Compounds of the present invention," and equivalent expressions, are meant to embrace
compounds of the Formula as described herein, which expression includes the pharmaceutically
acceptable salts, and the solvates, e.g., hydrates, where the context so permits.
Similarly, reference to intermediates, whether or not they themselves are claimed,
is meant to embrace their salts, and solvates, where the context so permits.
[0046] As used herein, the term "isotopic variant" refers to a compound that contains unnatural
proportions of isotopes at one or more of the atoms that constitute such compound.
For example, an "isotopic variant" of a compound can be radiolabeled, that is, contain
one or more nonradioactive or radioactive isotopes, such as for example, deuterium
(
2H or D), carbon-13 (
13C), nitrogen-15 (
15N), or the like. It will be understood that, in a compound where such isotopic substitution
is made, the following atoms, where present, may vary, so that for example, any hydrogen
may be
2H/D, any carbon may be
13C, or any nitrogen may be
15N, and that the presence and placement of such atoms may be determined within the
skill of the art. Likewise, the invention may include the preparation of isotopic
variants with radioisotopes, in the instance for example, where the resulting compounds
may be used for drug and/or substrate tissue distribution studies. Radiolabeled compounds
of the invention can be used in diagnostic methods such as single-photon emission
computed tomography (SPECT). The radioactive isotopes tritium, i.e.
3H, and carbon-14, i.e.
14C, are particularly useful for their ease of incorporation and ready means of detection.
Further, compounds may be prepared that are substituted with positron emitting isotopes,
such as
11C,
18F,
15O and
13N, and would be useful in Positron Emission Topography (PET) studies for examining
substrate receptor occupancy.
[0047] All isotopic variants of the compounds of the invention, radioactive or not, are
intended to be encompassed within the scope of the invention. In one aspect, provided
herein are deuterated or tritiated analogs of compounds described.
[0048] It is also to be understood that compounds that have the same molecular formula but
differ in the nature or sequence of bonding of their atoms or the arrangement of their
atoms in space are termed "isomers." Isomers that differ in the arrangement of their
atoms in space are termed "stereoisomers."
[0049] Stereoisomers that are not mirror images of one another are termed "diastereomers"
and those that are non-superimposable mirror images of each other are termed "enantiomers."
When a compound has an asymmetric center, for example, it is bonded to four different
groups, a pair of enantiomers is possible. An enantiomer can be characterized by the
absolute configuration of its asymmetric center and is described by the R- and S-sequencing
rules of Cahn and Prelog, or by the manner in which the molecule rotates the plane
of polarized light and designated as dextrorotatory or levorotatory (i.e., as (+)
or (-)-isomers respectively). A chiral compound can exist as either individual enantiomer
or as a mixture thereof. A mixture containing equal proportions of the enantiomers
is called a "racemic mixture."
[0050] "Tautomers" refer to compounds that are interchangeable forms of a particular compound
structure, and that vary in the displacement of hydrogen atoms and electrons. Thus,
two structures may be in equilibrium through the movement of π electrons and an atom
(usually H). For example, enols and ketones are tautomers because they are rapidly
interconverted by treatment with either acid or base. Another example of tautomerism
is the aci-and nitro-forms of phenyl nitromethane, that are likewise formed by treatment
with acid or base.
[0051] Tautomeric forms may be relevant to the attainment of the optimal chemical reactivity
and biological activity of a compound of interest.
[0052] Compounds of the invention may also exist as "rotamers," that is, conformational
isomers that occur when the rotation leading to different conformations is hindered,
resulting a rotational energy barrier to be overcome to convert from one conformational
isomer to another.
[0053] The compounds of this invention may possess one or more asymmetric centers; such
compounds can therefore be produced as individual (R)-or (S)-stereoisomers or as mixtures
thereof.
[0054] Unless indicated otherwise, the description or naming of a particular compound in
the specification and claims is intended to include both individual enantiomers and
mixtures, racemic or otherwise, thereof. The methods for the determination of stereochemistry
and the separation of stereoisomers are well-known in the art.
[0055] As used herein, the term "localized delivery" denotes delivery of a pharmaceutical
or therapeutic agent to a specific, limited region of the body.
[0056] As used herein, the term "systemic delivery" denotes delivery of a pharmaceutical
or therapeutic agent throughout the body, for example, through administration to the
circulatory system.
[0057] As used herein, the term "mass spectrometry (MS)" denotes an analytic technique that
ionizes a chemical compound to generate charged molecules or molecule fragments and
measures their abundance as a function of mass-to-charge (m/z) ratio (the mass spectrum).
From the mass spectrum, conclusions as to the structure of the chemical compound can
be drawn.
[0058] As used herein, the term "liquid chromatography - mass spectrometry (LCMS)" denotes
an analytic technique that combines the physical separation capability of liquid chromatography
with the analytic capability of mass spectrometry. In the liquid chromatography step,
the sample is introduced into a column packed with a stationary phase, separating
the chemical compounds of the sample by their retention time (Rt) in the column. The
chemical compound or compounds associated with a retention time interval are then
directed to a mass spectrometer, to obtain a mass spectrum that allows conclusions
as to the structure of this chemical compound or compounds to be drawn.
[0059] As used herein, the term "thin-layer chromatography (TLC)" denotes an analytic technique
that separates chemical compounds in a sample by the different rates in which they
are drawn up a plate coated with a stationary phase material.
[0060] As used herein, the term "nuclear magnetic resonance spectroscopy (NMR)" denotes
an analytic technique that measures the intensity of a resonance response of a set
of nuclei to a radio frequency pulse to allow information as to the electronic environment
of the nuclei to be obtained. From this, conclusions can be drawn as to the chemical
structure of the compound in which the nuclei reside. A nuclear magnetic resonance
spectroscopy technique that uses hydrogen nuclei (protons) is termed proton nuclear
magnetic resonance spectroscopy (
1HNMR).
[0061] The term "ester" is used herein as is conventional in the field of organic chemistry.
For example, the term "ester" can denote a carbonyl group with a bonded oxygen and
alkyl or an oxygen with a bonded carbonyl and alkyl.
[0062] As used herein, the term "metabolic syndrome" denotes a medical or biological disorder
of energy utilization and storage in an animal or human, which can be characterized
by abdominal obesity, elevated blood pressure, elevated fasting plasma glucose, high
serum triglycerides, and/or low high-density cholesterol levels.
[0063] As used herein, the term "polymerase chain reaction" denotes a biomedical technique
for generating many copies of a particular DNA sequence.
[0064] As used herein, the term "triturate" denotes a method of purifying a material in
which the crude material is washed with a solvent. The solvent can be selected, so
that the desired product is insoluble and the impurities are soluble, in which case,
the purified product is left in solid form and the impurities are removed with the
solvent. Conversely, the solvent can be selected, so that the desired product is soluble
and the impurities are insoluble, in which case, the purified product is in solution
and the impurities are removed as solids. The solvent can then be removed, for example,
through evaporation, to obtain the purified product.
[0065] As used herein, the term "Boc-protection" denotes functionalization of a chemical
compound with a tert-butyloxycarbonyl (Boc) group as a protecting group. This allows
the chemical compound as a whole to be treated with reagents that would otherwise
undesirably attack the unprotected group. The protected group can thereafter be deprotected
to yield the desired original group.
Exemplary Compounds
[0066] The present invention, provides a molecule having the structure of a compound of
the structure of Formula 1:

(2S,3S,6R,7aR)-1-(cyclopropylmethyl)-4-(3,3,3-trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridin-3-yl
pivalate, and stereoisomers thereof. This compound can be prepared by the reaction
sequences described in the Schemes set forth in Example 1.
Pharmaceutical Compositions and Administration
[0067] The compounds of the present invention are useful as pharmaceutical agents and can
be incorporated into pharmaceutical compositions comprising a therapeutically effective
amount of a compound of the invention, as defined herein, and a pharmaceutically acceptable
carrier or diluent.
[0068] The compounds of the invention can also be used in the manufacture of derivative
compounds that are useful as pharmaceutical agents, and which can likewise be incorporated
into pharmaceutical compositions prepared with a therapeutically effective amount
of such a derivative compound and a pharmaceutically acceptable carrier or diluent.
[0069] The compounds of the invention, and such derivatives thereof, can be useful in the
treatment of conditions, diseases, and disorders in humans and animals. Such compounds
can be formulated as pharmaceutical compositions and administered to a subject in
need of treatment, for example a mammal, such as a human patient, in a variety of
forms adapted to the chosen route of administration. For example compounds of the
invention may be formulated for administration, orally, nasally, intraperitoneally,
or parenterally, by intravenous, intramuscular, topical, or subcutaneous routes, or
by injection into tissue.
[0070] Thus, compounds of the invention may be systemically administered, e.g., orally,
in combination with a pharmaceutically acceptable vehicle such as an inert diluent
or an assimilable edible carrier, or by inhalation or insufflation. They may be enclosed
in hard or soft shell gelatin capsules, may be compressed into tablets, or may be
incorporated directly with the food of the patient's diet. For oral therapeutic administration,
the compounds may be combined with one or more excipients and used in the form of
ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups,
wafers, and the like. The compounds may be combined with an inert powdered carrier
and inhaled by the subject or insufflated. Such compositions and preparations should
contain at least 0.1% of a compound of the present invention. The percentage of the
compound of the invention present in such compositions and preparations may, of course,
be varied and may conveniently be between about 2% to about 60% of the weight of a
given unit dosage form. The amount of the compound in such therapeutically useful
compositions is such that an effective dosage level will be obtained.
[0071] The tablets, troches, pills, capsules, and the like may also contain the following:
binders such as gum tragacanth, acacia, corn starch or gelatin; excipients such as
dicalcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic
acid, and the like; a lubricant such as magnesium stearate; and a sweetening agent
such as sucrose, fructose, lactose, or aspartame, or a flavoring agent such as peppermint,
oil of wintergreen, or cherry flavoring may be added. When the unit dosage form is
a capsule, it may contain, in addition to materials of the above type, a liquid carrier,
such as a vegetable oil or a polyethylene glycol. Various other materials may be present
as coatings or for otherwise modifying the physical form of the solid unit dosage
form. For instance, tablets, pills, or capsules may be coated with gelatin, wax, shellac,
or sugar, and the like. A syrup or elixir may contain the active compound, sucrose
or fructose as a sweetening agent, methyl and propylparabens as preservatives, a dye,
and flavoring such as cherry or orange flavor. Of course, any material used in preparing
any unit dosage form should be pharmaceutically acceptable and substantially non-toxic
in the amounts employed. In addition, the compounds may be incorporated into sustained-release
preparations and devices. For example, the compounds may be incorporated into time
release capsules, time release tablets, time release pills, and time release polymers
or nanoparticles.
[0072] The compounds may also be administered intravenously or intraperitoneally by infusion
or injection. Solutions of the compounds can be prepared in water, optionally mixed
with a nontoxic surfactant. Dispersions can also be prepared in glycerol, liquid polyethylene
glycols, triacetin, and mixtures thereof, and in oils. Under ordinary conditions of
storage and use, these preparations can contain a preservative to prevent the growth
of microorganisms.
[0073] The pharmaceutical dosage forms suitable for injection or infusion can include sterile
aqueous solutions or dispersions or sterile powders comprising the compounds which
are adapted for the extemporaneous preparation of sterile injectable or infusible
solutions or dispersions, optionally encapsulated in liposomes. In all cases, the
ultimate dosage form should be sterile, fluid, and stable under the conditions of
manufacture and storage. The liquid carrier or vehicle can be a solvent or liquid
dispersion medium comprising, for example, water, ethanol, a polyol (for example,
glycerol, propylene glycol, liquid polyethylene glycols, and the like), vegetable
oils, nontoxic glyceryl esters, and suitable mixtures thereof. The proper fluidity
can be maintained, for example, by the formation of liposomes, by the maintenance
of the required particle size in the case of dispersions, or by the use of surfactants.
The prevention of the action of microorganisms can be brought about by various antibacterial
and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid,
thimerosal, and the like. In many cases, it will be preferable to include isotonic
agents, for example, sugars, buffers, or sodium chloride. Prolonged absorption of
the injectable compositions can be brought about by the use in the compositions of
agents delaying absorption, for example, aluminum monostearate and gelatin.
[0074] Sterile injectable solutions are prepared by incorporating the compounds in the required
amount in the appropriate solvent with various of the other ingredients enumerated
above, as required, preferably followed by filter sterilization. In the case of sterile
powders for the preparation of sterile injectable solutions, the preferred methods
of preparation are vacuum drying and freeze drying techniques, which yield a powder
of the active ingredient plus any additional desired ingredient present in the previously
sterile-filtered solutions.
[0075] For topical administration, the compounds may be applied in pure form. However, it
may be desirable to administer them to the skin as compositions or formulations, in
combination with a dermatologically acceptable carrier, which may be a solid or a
liquid.
[0076] Useful solid carriers include finely divided solids such as talc, clay, microcrystalline
cellulose, silica, alumina, and the like. Other solid carriers include nontoxic polymeric
nanoparticles or microparticles. Useful liquid carriers include water, alcohols, or
glycols, or water/alcohol/glycol blends, in which the compounds can be dissolved or
dispersed at effective levels, optionally with the aid of non-toxic surfactants. Adjuvants
such as fragrances and additional antimicrobial agents can be added to optimize the
properties for a given use. The resultant liquid compositions can be applied from
absorbent pads, used to impregnate bandages and other dressings, or sprayed onto the
affected area using pump-type or aerosol sprayers.
[0077] Thickeners such as synthetic polymers, fatty acids, fatty acid salts and esters,
fatty alcohols, modified celluloses, or modified mineral materials can also be employed
with liquid carriers to form spreadable pastes, gels, ointments, soaps, and the like,
for application directly to the skin of the user.
[0078] Examples of useful dermatological compositions which can be used to deliver the compounds
to the skin are known to the art; for example, see
Jacquet et al. (U.S. Pat. No. 4,608,392),
Geria (U.S. Pat No. 4,992,478),
Smith et al. (U.S. Pat. No. 4,559,157) and
Wortzman (U.S. Pat. No. 4,820,508).
[0079] The concentration of the therapeutic compounds of the invention in such formulations
can vary widely depending on the nature of the formulation and intended route of administration.
For example, the concentration of the compounds in a liquid composition, such as a
lotion, can preferably be from about 0.1 - 25% by weight, or, more preferably, from
about 0.5 - 10% by weight. The concentration in a semi-solid or solid composition
such as a gel or a powder can preferably be about 0.1 - 5% by weight, or, more preferably,
about 0.5 - 2.5% by weight.
[0080] Effective dosages and routes of administration of agents of the invention are conventional.
The exact amount (effective dose) of the agent will vary from subject to subject,
depending on, for example, the species, age, weight, and general or clinical condition
of the subject, the severity or mechanism of any disorder being treated, the particular
agent or vehicle used, the method and scheduling of administration, and the like.
A therapeutically effective dose can be determined empirically, by conventional procedures
known to those of skill in the art. See, e.g.,
The Pharmacological Basis of Therapeutics, Goodman and Gilman, eds., Macmillan Publishing
Co., New York. For example, an effective dose can be estimated initially either in cell culture
assays or in suitable animal models. The animal model may also be used to determine
the appropriate concentration ranges and routes of administration. Such information
can then be used to determine useful doses and routes for administration in humans.
Methods for the extrapolation of effective dosages in mice and other animals to humans
are known to the art; for example, see
U.S. Pat. No. 4,938,949. A therapeutic dose can also be selected by analogy to dosages for comparable therapeutic
agents.
[0081] The particular mode of administration and the dosage regimen will be selected by
the attending clinician, taking into account the particulars of the case (e.g., the
subject, the disease, the disease state involved, and whether the treatment is prophylactic).
Treatment may involve daily or multi-daily doses of compound(s) over a period of a
few days to months, or even years.
[0082] In general, however, a suitable dose will be in the range of from about 0.001 to
about 100 mg/kg of body weight per day, preferably from about 0.01 to about 100 mg/kg
of body weight per day, more preferably, from about 0.1 to about 50 mg/kg of body
weight per day, or even more preferred, in a range of from about 1 to about 10 mg/kg
of body weight per day. For example, a suitable dose may be about 1 mg/kg, 10 mg/kg,
or 50 mg/kg of body weight per day.
[0083] The compounds are conveniently administered in unit dosage form; for example, containing
about 0.05 to about 10000 mg, about 0.5 to about 10000 mg, about 5 to about 1000 mg,
or about 50 to about 500 mg of active ingredient per unit dosage form.
[0084] The compounds can be administered to achieve peak plasma concentrations of, for example,
from about 0.25 to about 200 µM, about 0.5 to about 75 µM, about 1 to about 50 µM,
about 2 to about 30 µM, or about 5 to about 25 µM. Exemplary desirable plasma concentrations
include at least 0.25, 0.5, 1, 5, 10, 25, 50, 75, 100 or 200 µM. For example, plasma
levels may be from about 1 to about 100 micromolar or from about 10 to about 25 micromolar.
This may be achieved, for example, by the intravenous injection of a 0.05 to 5% solution
of the compounds, optionally in saline, or orally administered as a bolus containing
about 1 to about 100 mg of the compounds. Desirable blood levels may be maintained
by continuous or intermittent infusion.
[0085] The compounds may conveniently be presented in a single dose or as divided doses
administered at appropriate intervals, for example, as one dose per day or as two,
three, four or more sub-doses per day. The sub-dose itself may be further divided,
e.g., into a number of discrete loosely spaced administrations; such as multiple inhalations
from an insufflator.
Example 1: Synthesis of a Compound of Formula I
[0086] A compound of Formula 1 was synthesized, from the compound of Formula 19 (Scopolamine
[51-34-3]) ((2S)-(1R,2R,4S,5S)-9-methyl-3-oxa-9-azatricyclo[3.3.1.02,4]nonan-7-yl-3-hydroxy-2-phenylpropanoate
hydrobromide trihydrate) by the steps described below in Schemes 1 through 18.
[0087] A first step is illustrated in Scheme 1.

[0088] Inside a 10 liter four necked round bottom flask, sodium borohydride (172 g, 4558
mmol) was added portion wise over about 2 hours to a mechanically stirred suspension
of a compound of Formula 19 (333 g, 760 mmol) in 3 liters of absolute ethanol in an
ice bath. During this time, gas formation occurred and the suspension was stirred
while being warmed to ambient temperature overnight. While being heated, at approximately
10 °C, sudden additional gas formation and foaming occurred.
[0089] The milky suspension was then concentrated to about half of its original volume (
i.e. from about 3 L to 1.5 L) with additional precipitate observed, which yielded the
batch. 5 M HCl in isopropyl alcohol (IPA) (5318 mmol, 1.064 L) was then diluted with
2 L of technical diethyl ether (Et
2O). The obtained hydrochloric acid (HCl) solution was then added drop wise to the
ice-chilled batch, while being stirred. The white suspension was allowed to be mechanically
stirred overnight to allow for full hydrolysis of the borate salts.
[0090] The reaction mixture was filtered and the resulting solid was rinsed twice with 500
mL portions of Et
2O. The dried solid (which contained some Et
2O) was dissolved in a minimum amount of 10% aqueous potassium carbonate (K
2CO
3) solution (∼1.5 L) until just a clear solution was obtained. 200 mL of brine and
∼50 g solid NaCl was added to the solution. The aqueous phase was then thoroughly
extracted with chloroform / methanol (MeOH) / [7N NH
3 in MeOH] (85:14:1). This procedure was performed 5 times with 1.0 L portions of this
solvent mixture each.
[0091] The combined organic extracts were dried (sodium sulphate (Na
2SO
4)), filtered and the solvent was removed under reduced pressure to give 102.2 g (659
mmol) of a compound of Formula 18 ((1R,2R,4S,5S)-9-methyl-3-oxa-9-azatricyclo[3.3.1.02,4]nonan-7-ol)
as a slightly tan oil at 87% yield.
1HNMR (CDCl
3) (Figure 1) showed structural agreement with the compound of Formula 18 with minor
amounts of impurities.
1HNMR (400 MHz, Chloroform-
d) δ 4.03-4.00 (m, 1H), 3.67 (s, 2H), 3.20-3.18 (m, 2H), 2.52 (s, 3H), 2.14-2.08 (m,
2H), 1.69 - 1.37 (m, 3H).
[0092] The next step proceeded as illustrated by Scheme 2.

[0093] To a solution of the compound of Formula 18 (102.2 g, 659 mmol), benzoic acid (BzOH)
(97 g, 790 mmol) and triphenylphosphine (PPh
3) (207 g, 790 mmol) in 1000 mL of dry tetrahydrofuran (THF) a solution of diisopropyl
azodicaboxylate (DIAD) (160 g, 790 mmol, 154 mL) in 100mL of dry THF was added drop
wise over a period of 4 hours. During the addition the solution was kept between -35
and -25 °C using acetone/dry ice. The clear, colorless solution was then removed from
the ice bath and stirred at room temperature overnight.
[0094] Samples were taken and analyzed, and the analysis showed the reaction went to completion.
The reaction mixture was concentrated, dissolved in 1 L of ethyl acetate (EtOAc),
extracted with 1 L of saturated sodium bicarbonate (NaHCO
3), and subsequently with aqueous 2 M HCl (1x1 L, 2x0.5 L). The combined acidic aqueous
fractions were washed once more with 1 L of EtOAc. Approximately 400 g of potassium
carbonate (K
2CO
3) was added portion wise to the acidic aqueous layer, while being stirred, until no
more gas formation was observed. The pH of the resulting solution was slightly basic
and slightly turbid and yellow.
[0095] The aqueous phase was then extracted with a dichloromethane (DCM) / MeOH 9:1 (3x,
1 L each) solution and the combined organic fractions were dried with sodium sulfate
(Na
2SO
4), filtered and concentrated to afford 118.3 g (447 mmol) of a compound of Formula
17 ((1R,2R,4S,5S,7r)-9-methyl-3-oxa-9-azatricyclo[3.3.1.02,4]nonan-7-yl benzoate),
which was then confirmed by MS (Figure 2) to have 98% purity at 67.9% yield.
1HNMR (400 MHz, Chloroform-
d) δ 8.07 - 7.93 (m, 2H), 7.59 - 7.48 (m, 1H), 7.44 - 7.40 (m, 2H), 5.39 - 5.30 (m,
1H), 3.63 (s, 2H), 3.42 - 3.25 (m, 2H), 2.57 (s, 3H), 2.10 - 2.04 (m, 2H), 1.92 -
1.86 (m, 2H).
[0096] The next step proceeded as illustrated in Scheme 3.

[0097] To a solution of the compound of Formula 17 (201.9 g, 779 mmol) in chloroform (350
mL) under a nitrogen atmosphere (not a stream), K
2CO
3 (452 g, 3270 mmol) and ethyl chloroformate (279 g, 2569 mmol, 247 mL) were added
to form a light yellow suspension which was then stirred under reflux overnight.
[0098] A sample was then taken and analyzed to show that the reaction had reached a 74%
conversion to the product, a compound of Formula 16 (1R,2R,4S,5S,7r)-ethyl 7-(benzoyloxy)-3-oxa-9-azatricyclo[3.3.1.02,4]
nonane-9-carboxylate). The mixture was further stirred at reflux temperature for another
24 hours.
[0099] Another sample was then taken and analyzed which showed that the reaction had reached
a 75% conversion to product. In order to drive the reaction toward completion, additional
K
2CO
3 (53.8 g, 389 mmol) and ethyl chloroformate (85 g, 779 mmol, 74.8 mL) were added to
the reaction solution and the mixture was stirred at reflux temperature overnight.
[0100] After being stirred and refluxed overnight, another sample was taken which was analyzed
to show that the reaction had reached 81% conversion to the compound of Formula 16.
[0101] The reaction mixture was then diluted with 500 mL of DCM and the organic layer was
washed with 750 mL of a half saturated aqueous NaHCO
3 solution, 750 mL of 0.4 M aqueous HCl, and 750 mL of brine. The mixture next dried
over Na
2SO
4, then filtered and concentrated under reduced pressure which then afforded a yellow
oil. 300 mL of Heptane was added and the mixture was vigorously stirred overnight.
[0102] A white suspension had formed which contained big white lumps which were crushed
with a spatula. The suspension was filtered over a glass filter, rinsed with approximately
250 mL of heptane and approximately 200 mL of pentane. The suspension was then dried
using a vacuum oven for 3 hours yielding the compound of Formula 16 as a white solid
(219.6 g, 692 mmol, 89% yield). LCMS of the product showed a percent yield greater
than 95%, with a mass and structure agreement with the desired product as shown in
the MS(Figure 3B) and
1HNMR (Figure 3A)).
1HNMR (400 MHz, Chloroform-
d) δ 8.01 - 7.97 (m, 2H), 7.61 - 7.53 (m, 1H), 7.48 - 7.42 (m, 2H), 5.48 - 5.39 (m,
1H), 4.58 (m, 1H), 4.48 (m, 1H), 4.16 (q,
J = 7.1 Hz, 2H), 3.56 - 3.53 (m, 2H), 2.34 - 2.21 (m, 2H), 1.98 - 1.86 (m, 2H), 1.27
(t,
J = 7.1 Hz, 3H).
[0103] The next step proceeded as illustrated in Scheme 4.

[0104] In a 6 L three necked flask, sodium borohydride (157 g, 4152 mmol) was added to a
suspension of the compound of Formula 16 (219.6 g, 692 mmol) in 1.5 L of absolute
ethanol at room temperature. The reaction was exothermic, and had an internal temperature
greater than 60 °C over a period of approximately 4 hours, during the reaction extreme
gas/foam formation was observed. The suspension was magnetically stirred at 50 °C
overnight.
[0105] A sample was then taken and analyzed by TLC to show that the reaction had gone to
completion. The resulting product was a white solid which stopped the magnetic stirrer
during the night. The mixture was concentrated under reduced pressure and the white
solid residue was partitioned between 1 L of chloroform and 3.5 L of half-saturated
aqueous NaHCO
3 solution. The layers were next separated and the aqueous layer was extracted with
additional chloroform (2x, 1 L each). The combined organic layers were washed with
1 L of brine, dried over Na
2SO
4, and filtered and concentrated under reduced pressure to afford approximately 220
g of the product as a white solid which was stirred in 0.6 L of heptane overnight
with a magnetic stirrer.
[0106] The mixture was then filtered off, the product had formed spheres which were crushed
and had 500 mL of heptane added to them. The mixture was stirred vigorously overnight
with a magnetic stirrer.
[0107] After stirring the mixture overnight, the off-white suspension still contained spheres
which then were crushed with a spatula. The suspension was filtered and the residue
was rinsed with approximately 300 mL heptane and dried by vacuum which yielded approximately
148 g of the product.
[0108] A sample was taken and analysed by
1HNMR to show the structure was in agreement with the compound of Formula 15 (1R,2R,4S,5S,7r)-ethyl
7-hydroxy-3-oxa-9-azatricyclo [3.3.1.02,4]nonane-9-carboxylate), (Figure 4).
[0109] The residue was then stirred in approximately 300 mL of Et
2O for 1 hour. The white suspension was filtered; and the residue was rinsed again
with approximately 300 mL of Et
2O and then dried by vacuum (under N
2-flow) to yield the compound of Formula 15 (122 g, 572 mmol, 82% yield).
1HNMR (400 MHz, Chloroform-
d) δ 4.50 (m, 1H), 4.41 (m, 1H), 4.23 - 4.09 (m, 3H), 3.42 - 3.39 (m, 2H), 2.15 - 2.08
(m, 2H), 1.73 - 1.62 (m, 2H), 1.44 (d,
J = 5.9 Hz, 1H), 1.26 (t,
J = 7.1 Hz, 3H).
[0110] The next step proceeded as illustrated in Scheme 5.

[0111] Triethylamine (22.78 g, 225 mmol, 31.4 mL) and mesyl-Cl (23.64 g, 206 mmol, 16.08
mL) was added drop wise to a solution of the compound of Formula 15 (40 g, 188 mmol)
in DCM (500 mL) at 0 °C. Once the addition was complete, the ice bath was removed
and the slightly milky suspension was stirred while warming to room temperature.
[0112] After 1 hour a sample was taken and analyzed by TLC which showed full conversion
had occurred. The reaction mixture was then washed twice with 500 mL of water. The
DCM layer appeared milky and was dried over Na
2SO
4 (which made the layer clearer), and then filtered and concentrated under reduced
pressure to afford a thick oil. The oil was stripped twice with toluene to afford
54.2 g of a light tan solid which contained 21 w% toluene.
[0113] The solid was further dried under vacuum at 50 °C until the weight remained constant
at 43.2 g (148 mmol; 78.9% yield) yielding a compound of Formula 14 ((1R,2R,4S,5S,7r)-ethyl
7-((methylsulfonyl)oxy)-3-oxa-9-azatricyclo[3.3.1.02,4]nonane-9-carboxylate). A sample
was taken and the structure was confirmed by
1HNMR (Figure 5).
1HNMR (400 MHz, Chloroform-
d) δ 5.11 - 5.02 (m, 1H), 4.54 - 4.53 (m, 1H), 4.44 - 4.43 (m, 1H), 4.13 (q,
J = 7.1 Hz, 2H), 3.47 - 3.45 (m, 2H), 3.00 (s, 3H), 2.28 - 2.23 (m, 2H), 2.00 - 1.90
(m, 2H), 1.25 (t,
J = 7.1 Hz, 3H).
[0114] The next step proceeded as illustrated in Scheme 6.

[0115] Potassium cyanide (12.14 g, 186 mmol) and 18-crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane)
(0.493 g, 1.864 mmol) were added to a solution of the compound of Formula 14 (19.89
g, 62.1 mmol, 91 %) in 300 mL of dry Dimethyl sulfoxide to form a pale yellow solution
which was stirred at 65 °C for two and a half days, or approximately 65 hours, to
yield a light brown solution.
[0116] A sample was taken and analyzed by TLC (heptane / DME 1:1, molybdate staining required),
which showed a clean conversion to the desired product (no exo-epimeric sideproduct
observed). However, at this time, it was found that the reaction had not run to completion
as starting material was also observed. The stirring was continued for a total of
118 hours, after which the brown solution was allowed to cool to room temperature,
and combined with an additional batch before being partitioned between 2 L of EtOAc
and 2 L of water.
[0117] The layers were separated and the organic layer was washed twice with 1 L of brine,
dried over Na
2SO
4, and filtered and concentrated under reduced pressure to afford the crude product,
a compound of Formula 13 ((1R,2R,4S,5S,7s)-ethyl 7-cyano-3-oxa-9-azatricyclo[3.3.1.02,4]nonane-9-carboxylate).
The product was purified by gravity column chromatography (750 g silica, heptane /
[5->50% EtOAc]) to afford 15.1 g of a white solid, or a compound of Formula 13. A
sample was taken and analyzed by
1HNMR (Figure 6) which demonstrated the product was in agreement with the structure
of Formula 13, although the product did contain 10 w% of the exo-sideproduct (which
was not problematic for the follow-up reactions) and 7.5 w% of heptane. The combined
yield from all experiments was 7.55 g, or 45% yield, after correction for solvent
and side product content.
1HNMR (400 MHz, Chloroform-
d) δ 4.53 - 4.52 (m, 1H), 4.43 - 4.41 (m, 1H), 4.12 (q,
J = 7.1 Hz, 2H), 3.70 - 3.68 (m, 2H), 2.93 - 2.89 (m, 1H), 2.22 - 2.12 (m, 2H), 2.04
- 1.98 (m, 2H), 1.24 (t,
J = 7.1 Hz, 3H).
[0118] The next step proceeded as illustrated in Scheme 7.

[0119] A 50% slurry of Raney-nickel in water was added to a solution of the compound of
Formula 13 (18.20 g, 82 mmol) in 350 mL of MeOH / 200 mL of ammonia (7N in MeOH).
The solution was kept under a nitrogen atmosphere and the Raney-nickel slurry was
added until a dark black suspension was obtained while being stirred vigorously.
[0120] The reaction vessel was evacuated and refilled with H
2 balloons, which was repeated twice, and then stirred at 45 °C under a H
2 atmosphere created by the balloons. After 3 hours, a sample was taken and analyzed
by TLC using heptane / dimethoxyethane (DME) 1:1, which demonstrated the reaction
was complete. The reaction mixture was filtered over a short pad of celite which was
pre-rinsed with MeOH. The residue was also rinsed with additional MeOH.
[0121] The filtrate was then concentrated under reduced pressure to give a light yellow
oil. This crude product consisted mainly of the open amines of a compound of Formula
12.a (1R,2R,4S,5S,7s)-ethyl 7-(aminomethyl)-3-oxa-9-azatricyclo[3.3.1.02,4]nonane-9-carboxylate
and to a lesser extent the (desired) cyclized amine a compound of Formula 12 (rac-(2R,3S,6S,7aS)-ethyl
3-hydroxyoctahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate).
[0122] To drive cyclization of the main endo-isomer to completion, the intermediate was
dissolved in 500 mL of absolute ethanol, which created a light yellow solution, which
was then stirred and refluxed overnight.
[0123] A sample was taken, concentrated under reduced pressure, dissolved in CDCl
3, and analyzed by
1HNMR (Figure 7) which showed the intermediate, open endo-isomer, had cyclized. It was
further shown that approximately 9% of the product was open exo-amine, and some solvent
remained.
1HNMR (400 MHz, Chloroform-
d) δ 4.46 - 4.01 (m, 5H), 3.50 - 3.44 (m, 1H), 3.16 - 3.11 (m, 1H), 3.96 - 2.93 (m,
1H), 2.10 - 1.66 (m, 5H), 1.47 (d,
J = 13.3 Hz, 1H), 1.26 (t,
J = 7.1 Hz, 3H).
[0124] The main batch, a yellow solution, was concentrated under reduced pressure and the
residue was redissolved in 500 mL of CHCl
3 and dried over Na
2SO
4. The solution was filtered and concentrated to give 21.7 g of a compound of Formula
12 as a thick yellow oil which contained solvent and the open exo-amine which was
used in the next step.
[0125] The next step proceeded as illustrated in Scheme 8.

[0126] Benzaldehyde (22.74 g, 214 mmol, 21.72 mL) was added to a solution of the compound
of Formula 12 (37.3 g, 165 mmol) in 1000 mL of dichloromethane. After 15 minutes STAB
(55.9 g, 264 mmol) was added. The suspension was then stirred at room temperature
overnight.
[0127] The reaction mixture was washed with 1 L of water and 1 L NaHCO
3. The organic layer was dried with Na
2SO4
2 and concentrated to dryness to afford 55 g of the reacted product, which was next
purified by gravity column chromatography (600 g, Hep/5-60% ETOAc) affording: 2.2
g of exo-Bn2N-adduct; and 35.3 g of a compound of Formula 11 (rac-(2R,3S,6S,7aS)-ethyl
3-hydroxyoctahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate) as analyzed
and confirmed by
1HNMR (Figure 8B) and MS (Figure 8A).
1HNMR (400 MHz, Chloroform-
d) δ 7.35 - 7.30 (m, 4H), 7.26 - 7.22 (m, 2H), 4.41 - 4.02 (m, 5H), 3.83 - 3.78 (m,
1H), 3.66 (d,
J = 13.3 Hz, 1H), 3.30 - 3.26 (m, 1H), 3.11 - 3.06 (m, 1H), 2.35 - 2.31 (m, 1H), 2.07
- 1.88 (m, 3H), 1.77 - 1.65 (m, 2H), 1.44 (d,
J = 13.9 Hz, 1H), 1.25 (t,
J = 7.1 Hz, 3H).
[0128] The next step proceeded as illustrated in Scheme 9.

[0129] Imidazole (15.19 g, 223 mmol) and tert-butyldiphenylchlorosilane (30.7 g, 112 mmol,
28.7 mL) were added to a solution of the compound of Formula 11 (35.3 g, 112 mmol)
in 100 mL of dry N,N-dimethylformamide to form a pale yellow solution which was stirred
at room temperature overnight.
[0130] After the stirring was complete a sample was taken and analyzed by LCMS which showed
the reaction was complete.
[0131] The solution was then concentrated under reduced pressure to yield an oily residue
which was diluted with 750 mL of DCM and washed with 750 mL of 1:1 saturated aqueous
NaHCO
3 solution and water. Next the solution was washed with 750 mL of brine. The organic
layer was dried over Na
2SO
4, filtered, and concentrated to afford approximately 65 g of the reacted product as
confirmed by TLC.
[0132] The reacted product was purified by gravity column chromatography (approximately
600 g, Hep/5-15% EtOAc) which afforded 59.5 g, or a 90% yield, of a compound of Formula
10 (rac-(2R,3R,6S,7aS)-ethyl 4-benzyl-3-((tert-butyldiphenylsilyl)oxy)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate)
as a very thick colorless oil. A sample was taken and analyzed by
1HNMR (Figure 9B) and LCMS (Figure 9A), which showed the product was in agreement with
the structure of Formula 10 and contained 6 w/w% heptane.
1HNMR (400 MHz, Chloroform-
d) δ 7.72 - 7.66 (m, 4H), 7.47 - 7.36 (m, 6H), 7.26 - 7.16 (m, 3H), 7.12 - 7.09 (m,
2H), 4.62 - 4.48 (m, 1H), 4.26 (s, 1H), 4.22 - 4.03 (m, 3H), 3.40 - 3.29 (m, 2H),
2.89 - 2.78 (m, 2H), 1.92 - 1.76 (m, 4H), 1.62 - 1.52 (m, 1H), 1.31 - 1.23 (m, 3H),
1.17 - 1.11 (m, 1H), 1.02 (s, 9H).
[0133] The next step proceeded as illustrated in Scheme 10.

[0134] Iodotrimethylsilane (75.0 g, 375 mmol, 51 ml) was added to a solution of the compound
of Formula 10 (73.9 g, 124 mmol, 93 %) in 1.2 L of dry toluene to create a yellow
reaction mixture which was stirred at 85 °C overnight.
[0135] A sample taken then taken and analyzed by TLC, which showed the reaction had gone
to completion. The resulting reaction mixture was a dark solution, and was allowed
to cool to room temperature (suspension) and quenched with 250 mL of MeOH. The mixture
was next concentrated to approximately 250 mL. After which 750 mL of DCM was added
and the mixture was washed with 750 mL of 1:1 saturated aqueous NaHCO
3 solution/H
2O. The organic layer was then washed with 750 mL of brine, dried over Na
2SO
4, filtered, and concentrated under reduced pressure to afford approximately 72 g,
or a 92% yield, of a compound of Formula 9 (rac-(2R,3R,6S,7aS)-4-benzyl-3-((tert-butyldiphenylsilyl)oxy)
octahydro-1H-2,6-methanopyrrolo [3,2-b]pyridine) as a dark yellow/orange oil. A sample
was taken and analyzed by LCMS (Figure 10) which showed the correct mass, and that
the product had a purity of about 80%, with the peak at 0.448 being toluene.
1HNMR (400 MHz, Chloroform-
d) δ 7.69 - 7.63 (m, 4H), 7.47 - 7.37 (m, 6H), 7.26 - 7.12 (m, 5H), 4.36 (s, 1H), 3.73
- 3.70 (m, 1H), 3.39 (d,
J = 13.7 Hz, 1H), 3.26 (d,
J = 7.6 Hz, 1H), 3.06 (s, 1H), 2.90 (d,
J = 13.7 Hz, 1H), 2.79 - 2.74 (m, 1H), 2.41 (bs, 1H), 1.90 - 1.80 (m, 4H), 1.67 - 1.64
(m, 1H), 1.11- 0.99 (m, 10H).
[0136] The next step proceeded as illustrated in Scheme 11.

[0137] Et
3N (48.3 g, 477 mmol, 0.067 L) and di-tert-butyl dicarbonate (Boc
2O) (39.1 g, 179 mmol) was added to a solution of the compound of Formula 9 (72 g,
119 mmol, 80 %) in 1 L of dichloromethane to form a light yellow solution which was
stirred at room temperature over weekend.
[0138] A sample taken and analyzed by TLC which showed the reaction was complete. The solution
was diluted with 250 mL of DCM and washed with 1 L of saturated aqueous NaHCO
3 solution and 1 L of brine. The organic layer was then dried over Na
2SO
4, filtered, and concentrated to afford approximately 80 g of the crude product.
[0139] Purification by gravity column chromatography (800 g, heptane / [EtOAc 1->10%]) afforded
68.4 g, or a 94% yield, of a compound of the Formula 8 (rac-(2R,3R,6S,7aS)-tert-butyl
4-benzyl-3- ((tert-butyldiphenylsilyl)oxy)octahydro-1H-2, 6-methanopyrrolo[3,2-b]pyridine-1-carboxylate)
as a colorless glass.
[0140] A sample was taken and analyzed by
1HNMR (Figure 11A) and LCMS (Figure 11B) which showed agreement between the product
and the structure of Formula 8, and further showing that the product contained 4 w/w%
heptane.
1HNMR (400 MHz, Chloroform-
d) δ 7.73 - 7.65 (m, 4H), 7.47 - 7.35 (m, 6H), 7.24 - 7.10 (m, 5H), 4.53 - 4.40 (m,
1H), 4.24 (d,
J = 3.8 Hz, 1H), 4.10 - 3.92 (m, 1H), 3.44 - 3.32 (m, 2H), 2.87 (d,
J = 13.6 Hz, 1H), 2.33 - 2.77 (m, 1H), 1.93 - 1.72 (m, 4H), 1.65 - 1.54 (m, 1H), 1.50
- 1.47 (m, 9H), 1.10 - 1.02 (m, 10H).
[0141] The next step proceeded as illustrated in Scheme 12.

[0142] Under a nitrogen flow, Palladium, 10% on activated carbon (7 g, 125 mmol) was added
to a solution of the compound of Formula 8 (72.9 g, 125 mmol) in 600 mL of acetic
acid. The vessel was closed and the resulting mixture was stirred at 50 °C for 2 hours
under a hydrogen atmosphere created by a balloon.
[0143] The mixture was then stirred at 50 °C overnight. The black suspension was filtered
over EtOH rinsed celite and the filtrate was concentrated under reduced pressure.
The residue was stripped twice with 0.5 L of toluene, after which it was dissolved
in 1 L of diethyl ether.
[0144] The organic layer was then washed with 1 L of 10% (w/v) aqueous K
2CO
3 solution, 1 L of brine, dried over Na
2SO
4, filtered, and concentrated under reduced pressure before being stripped again with
pentane to afford 58.5 g of a thick tan syrup, a compound of Formula 7 (rac-(2R,3
S,6S,7aS)-tert-butyl 3-((tert -butyldiphenylsilyl)oxy)octahydro-1H-2,6-methanopyrrolo
[3,2-b]pyridine-1-carboxylate).
[0145] A sample was taken and analyzed by
1HNMR (Figure 12B) and LCMS (Figure 12A) which showed the product was in agreement with
structure of Formula 7 and contained 5.1 weight% of toluene and 1.3 weight% of
n-pentane.
1HNMR (400 MHz, Chloroform-
d) δ 7.68 - 7.63 (m, 4H), 7.45 - 7.35 (m, 6H), 4.40 - 4.25 (m, 1H), 4.13 - 3.93 (m,
2H), 3.41 - 3.36 (m, 1H), 2.97 - 2.92 (m, 1H), 2.62 (d,
J = 11.5 Hz, 1H), 1.96 - 1.78 (m, 2H), 1.67 (s, 1H), 1.64 - 1.56 (m, 1H), 1.49 - 1.47
(m, 9H), 1.16 - 1.13 (m, 1H), 1.05 - 1.04 (m, 9H).
[0146] The compound of Formula 7 was separated into its respective enantiomers via supercritical
fluid chromatography (SFC) on a Welkho-1 column with 90/10 scCO
2/iPrOH + 0.2% isopropylamine eluent as as illustrated in Scheme 13.

[0147] The next step proceeded as illustrated in Scheme 14.

[0148] 3,3,3-trifluoropropanoic acid (3.629 mL, 41.1 mmol, 1.5 eq) was dissolved in DCM
(120 mL) and dry DMF (10 mL). DIPEA (7.16 mL, 41.1 mmol, 1.5 eq) and HATU (1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium
3-oxidhexafluorophosphate) (15.63 g, 41.1 mmol, 1.5 eq) were added and the mixture
was stirred at room temperature for 1.5 hours. This resulted in the formation of a
clear red-brown solution.
[0149] To that solution, a solution of the compound of Formula 6.b (13.5g, 27.4 mmol) in
DCM (100 mL) was added and the solution was stirred for at room temperature for 4
hours.
[0150] The reaction mixture was diluted with DCM (250 mL), washed with aqueous 1 M KHSO
4 (400 mL), saturated aqueous NaHCO
3 (400 mL), water (400 mL), brine (250 mL), dried over Na
2SO
4 and concentrated in vacuo to afford 22.74 g (> 100%) a compound of Formula 5 ((2S*,3S*,3aS*,6R*,7aR*)-tert-butyl
3-((tertbutyldiphenylsilyl)oxy)-4-(3,3,3 trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate)
as a brown oil.
[0151] The next step proceeded as illustrated in Scheme 15.

[0152] The compound of Formula 5 (max 27.4 mmol) was dissolved in dry THF (115 mL).
[0153] A solution of tetrabutylammonium fluoride in THF (1 M, 82 mL, 82 mmol) was added
and the reaction mixture was stirred at 50 °C overnight. LCMS analysis revealed complete
conversion to desired material.
[0154] The solution was concentrated in vacuo and co-evaporated twice with 50% EtOAc/heptane
(2 x, each 100 mL) to afford 38.66 g of crude material as a brown oil. The material
was dissolved in 25% EtOAc/Et
2O (800 mL) and washed with water (2 x, each 600 mL). The aqueous layers were combined
and extracted with 25% EtOAc/Et2O (400 mL). The organic layers were combined, washed
with brine (400 mL), dried over Na
2SO
4 and concentrated in vacuo to afford 15.14 g of material as a brown oil.
[0155] Purification by gravitation column chromatography (gradient 50% EtOAc/heptane to
100% EtOAc) yielded 5.85 g of a compound of Formula 4 ((2S*,3S*,3aS*,6R*,7aR*)-tert-butyl
3-hydroxy-4-(3,3,3- trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate)
(58% over 2 steps) as a white foam.
[0156] The next step proceeded as illustrated in Scheme 16,

[0157] The compound of Formula 4 (5.85 g, 16 mmol) was dissolved in pyridine (50 mL), followed
by the addition of DMAP (dimethylaminopyridine) (1.96 g, 16.06 mmol) and pivaloyl
chloride (3.95 mL, 32.1 mmol).
[0158] The reaction mixture was stirred overnight at 60°C. LCMS analysis revealed complete
conversion to desired material. The reaction mixture was allowed to cool to room temperature
(a light brown suspension formed) and concentrated in vacuo.
[0159] The residue was diluted with EtOAc (250 mL) and washed with aqueous 0.5 M KHSO
4 (200 mL) and saturated aqueous NaHCO
3 (250 mL). Each time the aqueous layer was extracted with additional EtOAc (50 mL).
[0160] The combined organic layers were washed with brine (200 mL), dried with sodium sulfate,
filtered and evaporated to dryness to yield 6.8 g of crude material. Purification
by flash column chromatography (EtOAc/heptane gradient) afforded 5.49 g (76%) of a
compound of Formula 3 ((2S*,3S*,3aS*,6R*,7aR*)-tert-butyl 3-(pivaloyloxy)-4-(3,3,3-
trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridine-1-carboxylate) as
a white foam. LCMS analysis: purity > 95%, found 449.3 [M+H]+ & 393.2 (M-(C4H8)+H]+).
[0161] The next step proceeded as illustrated in Scheme 17.

[0162] The compound of Formula 3 (1 g, 2.23 mmol) was dissolved in DCM (20 mL).
[0163] TFA (trifluoroacetic acid) (8.54 mL, 111 mmol) was added and the mixture was stirred
at room temperature for 1 h. LCMS analysis revealed complete conversion to desired
material.
[0164] The reaction mixture was concentrated in vacuo and co-evaporated with toluene (2
x, each 20 mL). The residue was dissolved in chloroform (40 mL) and washed with aqueous
saturated Na
2CO
3 solution (40 mL). The aqueous phase was extracted with chloroform (3 x, each 20 mL).
[0165] The organic layers were combined, washed with brine (70 mL), dried (Na
2SO
4), filtered and evaporated under reduced pressure to afford 769.9 mg (99%) of a compound
of Formula 2 ((2S*,3S*,3aS*,6R*,7aR*)-4-(3,3,3-trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridin-3-yl
pivalate) as an off-white solid. The structure was confirmed by
1HNMR as shown in Figure 13.
[0166] The next step proceeded as illustrated in Scheme 18,

[0167] To the compound of Formula 2 (199.8 mg; 0.574 mmol) in dichloromethane (2 mL), cyclopropylcarboxaldehyde
(55.7 uL; 0.523 mmol) was added, and the reaction mixture was stirred for 2 hours
at room temperature. Next sodium triacetoxyborohydride (200.7 mg; 0.947 mmol) was
added to the reaction mixture, and the reaction mixture was stirred at room temperature
overnight. The reaction mixtures were evaporated to dryness under reduced pressure.
Purification by prep LCMS followed by evaporation of the solvents under reduced pressure
(Genevac) afforded a compound of Formula 1 ((2S,3S,6R,7aR)-1-(cyclopropylmethyl)-4-(3,3,3-trifluoropropanoyl)octahydro-1H-2,6-methanopyrrolo[3,2-b]pyridin-3-yl
pivalate). (MH+ = 403.1).
[0168] An overview of these synthetic steps to transform the starting reactant into a compound
of Formula 1 is provided in Scheme 19, below.

Example 2: In Vivo Activity of the Compound of Formula 1
[0169] Table 7 summarizes the activity of Formula 1 in mice models of neuropathic pain following
repeated daily administration using different routes of administration.
Table 7: Summary of the activity of Formula 1 in animal models for neuropathic pain
in mice.
| TI |
Model |
Route |
Doses Tested (mg/kg) |
Level of activity (% of maximum effect-baseline) |
Duration of activity at maximum effect |
Peak of activity (T) |
Dose of maximum activity (mg/kg) |
| Gabapentin |
CCI |
IP |
150 |
66% |
4-6H |
2-3H |
150 |
| SC |
150 |
64% |
4-6H |
2-3H |
150 |
| SC |
150 |
>100% |
4-6H |
2-3H |
150 |
| Gabapentin |
Taxol |
SC |
150 |
100% |
4 H |
2-4H |
150 |
| Formula 1 |
Taxol |
SC |
1,3,10 |
100% |
3 day |
1H-3 days |
1 |
| Gabapentin |
Taxol |
PO |
150 |
100% |
4 H |
2-4H |
150 |
| Formula 1 |
Taxol |
PO |
30 |
100% |
3 days |
1-24 H |
<30 |
[0170] The embodiments illustrated and discussed in this specification are intended only
to teach those skilled in the art the best way known to the inventors to make and
use the invention. Nothing in this specification should be considered as limiting
the scope of the present invention. All examples presented are representative and
non-limiting. The above-described embodiments of the invention may be modified or
varied, without departing from the invention, as appreciated by those skilled in the
art in light of the above teachings.
[0171] It should be understood that although the compounds of Formulas 1-18 may be drawn
with specific chirality for the sake of simplicity, one skilled in the art would recognize
how to create and separate these various isomers. Accordingly, all isomers of the
compounds of Formulas 1-18 may be understood to be within the scope of the present
application.