WO 2006/069154 PCT/US2005/046361
VITAMIN D RECEPTOR MODULATORS
REFERENCE TO RELATED APPLICATION
This application claims the benefit of priority under title 35 United States Code §
119(e) of Provisional Patent Application No. 60/638,029 filed December 21, 2004, which
is incorporated herein by reference in its entirety
BACKGROUND OF THE INVENTION
Vitamin D Receptor (VDR) is a ligand dependent transcription factor that belongs
to the superfamily of nuclear hormone receptors. The VDR protein is 427 amino acids,
with a molecular weight of -50 kDa. The VDR ligand, la,25-dihydroxyvitamin D3 (the
hormonally active form of Vitamin D) has its action mediated by its interaction with the
nuclear receptor known as Vitamin D receptor ("VDR"). The VDR ligand, la,25-
dihydroxyvitamin D3 (lα,25(OH)2D3) acts upon a wide variety of tissues and cells both
related to and unrelated to calcium and phosphate homeostasis.
The activity of la,25-dihydroxyvitamin D3 in various systems suggests wide
clinical applications. However, use of conventional VDR ligands is hampered by their
associated toxicity, namely hypercalcemia (elevated serum calcium). Currently,
lα,25(OH)2D3j marketed as Rocaltrol® pharmaceutical agent ( product of Hoffmann-La
Roche), is administered to kidney failure patients undergoing chronic kidney dialysis to
treat hypocalcemia and the resultant metabolic bone disease. Other therapeutic agents,
such as Calcipotriol® (synthetic analog of loc,25(OH)2D3 ) show increased separation of
binding affinity on VDR from hypercalcemic activity.
Chemical modifications of lα,25(OH)2D3 have yielded analogs with attenuated
calcium mobilization effects (R. Bouillon el. al., Endocrine Rev. 1995,16,200-257). One
such analog, Dovonex ® pharmaceutical agent (product of Bristol-Meyers Squibb Co.), is
currently used in Europe and the United States as a topical treatment for mild to moderate
psoriasis (K. Kragballe et. al., Br. J. Dermatol. 1988,119, 223-230).
Other Vitamin D3 mimics have been described in the publication, Vitamin D
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Analogs: Mechanism of Action of Therapeutic Applications, by Nagpal, S.; Lu, J.;
Boehm, M. R, Curr. Med. Chem. 2001, 8, 1661-1679.
Although some degree of separation between the beneficial action and calcium
raising (calcemic) effects has been achieved with these VDR ligands, to date the
separation has been insufficient to allow for oral administration to treat conditions such as
osteoporosis, cancers, leukemias, and severe psoriasis.
One example of a major class of disorder that could benefit from VDR mediated
biological efficacy in the absence of hypercalcemia is osteoporosis. Osteoporosis is a
systemic disorder characterized by decreased bone mass and microarchitectural
deterioration of bone tissue leading to bone fragility and increased susceptibility to
fractures of the hip, spine, and wrist (World Health Organization WHO 1994).
Osteoporosis affects an estimated 75 million people in the United States, Europe, and
Japan.
Within the past few years, several antiresorptive therapies have been introduced.
These include bisphosphonates, hormone replacement therapy (HRT), a selective
estrogen receptor modulator (SERM), and calcitonins. These treatments reduce bone
resorption, bone formation, and increase bone density. However, none of these
treatments increase true bone volume nor can they restore lost bone architecture.
Another major disorder that could benefit from VDR mediated biological activity
is psoriasis. Psoriasis is one of the most common dermatologic diseases and is a chronic
inflammatory skin condition characterized by erythematous, sharply demarcated papules
and rounded plaques, covered by silvery micaceous scale.
Synthetic VDR ligands with reduced calcemic potential have been synthesized.
For example, a class of bis-phenyl compounds stated to mimic la, 25-dihydroxyvitamin
D3 is described in US Patent No. 6,218,430 and the article; "Novel nonsecosteroidal
vitamin D mimics exert VDR-modulating activities with less calcium mobilization than
lα, 25-Dihydroxyvitamin D3" by Marcus F. Boehm, et. al., Chemistry & Biology 1999.
Vol 6, No. 5, pgs. 265-275.
Synthetic VDR ligands having an aryl-thiophene nucleus are described in United
States provisional patent application SN 60/384,151, filed 29 May 2002 (WO
03/101,978), and synthetic VDR ligands having aryl-napthaline nucleus are described in
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WO 2006/069154 PCT/US2005/046361
United States provisional patent application SN 60/637,930 filed 21 December 2004.
There remains a need for improved treatments using alternative or improved
pharmaceutical agents that mimic la, 25-dihydroxyvitamin D3 to stimulate bone
formation, restore bone quality, and treat other diseases without the attendant
disadvantage of hypercalcemia.
SUMMARY OF THE INVENTION
Novel compounds having a phenyl-benzoxazole nucleus of Formula "(XP)" have
been found effective as Vitamin D Receptor modulators (VDRM):

wherein the variables R, R', RP, RP3, Lp1, LP2, Zp, RB, RB', LXB and ZXB are as
hereinafter defined.
In another aspect, the present invention is directed towards pharmaceutical
compositions containing pharmaceutically effective amounts of compounds of
Formula I or a pharmaceutically acceptable salt or a prodrug thereof, either singly or in
combination, together with pharmaceutically acceptable carriers and/or auxiliary agents.
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Another aspect of the invention is a pharmaceutical formulation for treatment or
prevention of osteoporosis containing pharmaceutically effective amounts of the vitamin
D receptor modulator compound of Formula I alone or together with pharmaceutically
effective amounts of co-agents conventionally used for the treatment of osteoporosis.
Another aspect of the invention is a pharmaceutical formulation for treatment or
prevention of psoriasis containing pharmaceutically effective amounts of the vitamin D
receptor modulator compound of Formula 1 alone or together with pharmaceutically
effective amounts of co-agents conventionally used for the treatment of psoriasis.
Another aspect of the invention is a pharmaceutical formulation for treatment or
prevention of prostate cancer containing pharmaceutically effective amounts of the
vitamin D receptor modulator compound of Formula I alone or together with
pharmaceutically effective amounts of co-agents conventionally used for the treatment of
prostate cancer.
Another aspect of the invention is to use the compounds of Formula I to treat
disease states responsive to Vitamin D receptor ligands.
Another aspect of the invention is the prevention and treatment of acne, actinic
keratosis, alopecia, Alzheimer's disease, autoimmune induced diabetes, benign prostatic
hyperplasia, bladder cancer, bone fracture healing, breast cancer, Crohn's disease,
prostate cancer, colon cancer, Type I diabetes, host-graft rejection, hypercalcemia, Type
II diabetes, leukemia, multiple sclerosis, insufficient sebum secretion, osteomalacia,
osteoporosis, insufficient dermal firmness, periodontal disease, insufficient dermal
hydration, myelodysplastic syndrome, psoriatic arthritis, psoriasis, renal osteodystrophy,
rheumatoid arthritis, scleroderma, seborrheic dermatitis, skin cancer, systemic lupus
erythematosis, skin cell damage from mustard vesicants, ulcerative colitis, and wrinkles,
by administering to a mammal in need thereof a pharmaceutically effective amount of a
compound of Formula I.
DETAILED DESCRIPTION OF THE INVENTION
Definitions:
The term, "abscess" refers to adverse complications often associated with surgery,
trama, or diseases that predispose the host to abscess formation from encapsulated
bacteria lymphocytes, macrophages, and etc.
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The term, "adhesion" refers to the adverse and abnormal union of surfaces
normally separate by the formation of new fibrous tissue resulting from an inflammatory
process.
The term, "compound of the invention" refers to a compound represented by
Formula I or as set out as products of the Examples or synthesis schemes described
herein.
The term, "Active Ingredient" means a compound of the invention.
The term, "mustard" is inclusive of both sulfur mustards and nitrogen mustards,
either alone or in any combination. Examplary of such compounds are the vesicants;
bis(2-chloroethyl) sulfide (Chemical Agent Symbol HD), C1(CH2)2S(CH2)2C1 1,2-
bis(2-chloroediylthio)ethane (Chemical Agent Symbol Q), C1(CH2)2S(CH2)2S(CH2)2C1;
bis(2-chloroethylthioethyl) ether, C1(CH2)2S(CH2)O(CH2)2S(CH2)2C1 (Chemical Agent
Symbol T); tris(2-chloroethyl) amine (Chemical Agent Symbol HN3) N(CH2CH2C1)3;
N-methyl-2,2'-dichlorodiethylamine (Chemical Agent Symbol NH2); and 2,2'-
dichlorotriethylamine, CH3CH2N(CH2CH2C1)2 (Chemical Agent Symbol NH1).
6
The term heteroaryl as used herein refers to the heteroaryls illustrated below:


WO 2006/069154 PCT/US2005/046361

where the dotted line crossing a solid line symbol represents a bond of attachment
between the atom of the radical and the rest of the molecule.
The term, "(Acidic Group)" means an organic group that acts as a proton donor
capable of hydrogen bonding. Illustrative of an (Acidic Group) is a group selected from
the following: carboxylic acid, acylsulfonamide, tetrazolyl, substituted heteroaryls with
acidic hydrogens, i.e., hydroxyl groups.
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The term, "mammal" includes humans.
The terms "halo" and halogen refer to fluorine, chlorine, bromine, and iodine.
Preferred halogens for the present invention include fluorine. .
Unless specified herein, chemical terms are used in their customary usuage as
understood by one skilled in the art.
The term, "C1-3 alkyl" refers to an alkyl group selected from methyl, ethyl, n-
propyl, and isopropyl. The abbreviations, "Me" means methyl; "Et" means ethyl; "iPr" or
"i-Pr" means 1 -methylethyl; and "tBu" or "t-Bu" means 1,1-dimethylethyl. The alkyl
group whether used singularly or in conjunction with other substituent(s) is attached to
the referenced compound through a carbon atom of the alkyl group.
The term, "branched C3-C5 alkyl" is an alkyl group selected from 1-methylethyl;
1-methylpropyl; 2-methylpropyl; 1,1-dimethylethyl; 1,1-dimethylpropyl; 1,2-
dimethylpropyl; or 2,2-dimethylpropyl. Preferred branched C3-C5 alkyl groups are 2-
methylpropyl and 1,1-dimethylethyl, with the 1,1-dimethylethyl group being most
preferred.
The term "alkenyl" refers to aliphatic groups wherein the point of attachment is a
carbon-carbon double bond, for example vinyl, 1-propenyl, and 1 -cyclohexenyl. Alkenyl
groups may be straight-chain, branched-chain, cyclic, or combinations thereof, and may
be optionally substituted. It will be understood that alkenyl groups can include one or
more double bonds. Further, the alkenyl groups can include positional isomers about the
double bonds i.e. trans (Z) or cis (E) isomers. Suitable alkenyl groups have from 2 to
about 20 carbon atoms.
The term "C1-C5 alkyl" refers to saturated aliphatic groups including straight-
chain, branched-chain, and cyclic groups and any combinations thereof. Examples of Cj-
C5 alkyl groups are methyl, ethyl, n-propyl, from 1-methylethyl; n-butyl, 1-methylpropyl;
2-methylpropyl; 1,1-dimethylethyl; n-amyl, 1,1-dimethylpropyl; 1,2-dimethylpropyl; and
2,2-dimethylpropyl.
The term "cycloalkyl" includes organic radicals having 3 to 8 carbon atoms as
ring members. Examples include: cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.
When substituted, the substituents can be selected from halo, hydroxyl, -CN, C1-C3 alkyl,
-SH,-OC1-C3 alkyl, and -SC,-C3 alkyl.
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The term, "cycloalkenyl" includes organic radicals having 3 to 8 carbon atoms as
ring members; non-limiting examples include: cyclopropenyl, cyclobutenyl,
cyclopentenyl and cyclohexenyl.
The term, "C1-C5 haloalkyl"is an alkyl group containing one or more halogen
atoms. The term, "C1-C5 fluoroalkyl"is an alkyl group containing fluorine and includes
organic radicals such as -CF3, -CHF2, -CH2F, -CF2CF3, -CHFCF3, -CH2CF3,
-CH2CHF2, and -CH2CH2F, with -CF3 being preferred.
The term,"hydroxyalkyl" means an alkyl group having at least one hydroxyl
group. Non-limiting examples include: 3-methyl-3-hydroxypentyl, 3-methyl-3-
hydroxypentenyl, 3-methyl-3-hydroxypentynyl, 3-cthyl-3-hydroxypentyl, 3-ethyl-3-
hydroxypentenyl, 3-ethyl-3-hydroxypentynyl, 3-ethyl-3-hydroxy-4-methylpentyl, 3-ethyl-
3-hydroxy-4-methylpentenyl, 3-ethyl-3-hydroxy-4-methylpentynyl, 3-propyl-3-
hydroxypentyl, 3-propyl-3-hydroxypentenyl, 3-propyl-3-hydroxypentynyl, l-hydroxy-2-
methyl-l-(methylethyl)propyl, 2-methyl-3-hydroxy-4,4-dimethylpentyl, 2-methyl-3-
hydroxy-3-ethylpentyl, 2-ethyl-3-hydroxy-3-ethylpentyl, 2-ethyl-3-hydroxy-4,4-
dimethylpentyl, 1-hydroxycycloalkenyl; and 1-hydroxycycloalkyl.
The term "hydroxycycloalkyl" refers to a radical having the general structural
formula:

where w is an integer from 1 to 6 and the hydroxyl radical is substituted on any ring
carbon atom. Examples include: 2-hydroxycyclohexylmethyl, 3-methyl-2-
hydroxycyclohexyloxy, 3-methy]-2-hydroxycyclohexylmethyl, and 3,3-dimethyl-2-
hydroxycyclohexyloxy.
The term "1-hydroxycycloalkyl" refers to a radical having the general structural
formula:
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where w is defined as above. Examples of 1-hydroxycycloalkyl radicals include: 1-
hydroxycyclopropyl, 1-hydroxycyclobutyl, 1-hydroxycyclopentyl, 1-hydroxycyclohexyl,
1-hydroxycyclpheptyl, and 1-hydroxycyclooctyl.
The term oxocycloalkyl refers to a radical having the general structural formula:

where w is defined as above. The bond of attachment of the oxocycloalkyl to the
referenced molecule need not be restricted to the carbon adjacent to the carbonyl carbon,
but can be attached via any of the carbon atoms making up the ring. Non limiting
examples of oxocycloalkyl radicals include: 2-oxocyclohexyloxy, 2-
oxocyclohexylmethyl, 3-methyl-2-oxocyclohexyloxy, 3-methyl-2-oxocyclohexylmethyl,
3,3-dimethyl-2-oxocyclohexyloxy, 3,3-dimethyl-2-oxocyclohexylmethyl, and 2-
hydroxycyclohexyloxy.
10
Certain compounds of the invention exist in isomeric configurations with chiral
centers, i.e., diastereomers and enatiomers. Each of the isomeric forms of the compounds
are contemplated to be within the scope of the present invention. Each of the various
isomers can be prepared as single isomers and/or separated into single isomers by
techniques known to those skilled in the art. Therefore, the compounds of the present
invention can be used either as single isomer or isomeric form or alteneratively the
compounds of the present invention can be used as a combination of isomers. The
"jagged" bond illustrated below is used to represent that carbon to which it is attached can
exist as either configuration, i.e., R or S.


WO 2006/069154 PCT/US2005/046361
It also will be understood by thoses skilled in the art that compounds of the present
invention can exist in two or more tautomeric forms. All such automeric froms are
contemplated to be included within the scope of the present invention.
Compounds of the Invention:
The compounds of the invention with vitamin receptor modulating (VDRM)
activity are represented by Formula (I) or a pharmaceutically acceptable salt or a prodrug
derivative thereof:

wherein
R and R1 are independently C1-C5 alky), C1-C5 haloalkyl, or together R and R'
form a substituted or unsubstituted, saturated or unsaturated cycloalkyl ring having from
3 to 8 carbon atoms;
RP3 and RB are independently selected from the group consisting of hydrogen,
halo, C1-C5 alkyl, C1-C5 haloalkyl, -O-C1-C5 alkyl, -S-Cj-Cs alkyl, -O-C1-C5
haloalkyl, -CN, -NO2, acetyl, -S-C1-C5 haloalkyl, C2-C5 alkenyl, C3-C5 cycloalkyl,
and C3-C5 cycloalkenyl;
RP and RB' are independently selected from: hydrogen, halo, C1-C5 alkyl, C1-
C5 haloalkyl, -O-C1-C5 alkyl, -S-C1-C5 alkyl, -O-C1-C5 haloalkyl, -CN, -NC7, acetyl,
-S-C1-C5 haloalkyl, C2-C5 alkenyl, C3-C5 cycloalkyl, or C3-C5 cycloalkenyl;
(Lpi), (Lp2), and (LXB) are divalent linking groups independently selected from the
group consisting of: a bond, -(CH2)m-C(OH)-, -(CH2)m-O-, -(CH2)m-S-,-(CH2)m-S(O)-,
-(CH2)m-S(O)2-, -(CH2)m-N(R40)-, -(CH2)m-C(R40)(R41)-, -(CH2)m-C(O)-,
-N(R40)-C(O)-, -(CH2)m-CH=CH-, and -(CH2)m-C=C-;
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where m is 0-5;
R40 and R41 each is independently selected from: hydrogen, C1-C5 alkyl, C\-
C5 hydroxyalkyl, C1-C5 haloalkyl, C2-C5 alkenyl, C3-C5 cycloalkyl, C3-C5
cycloalkenyl;
Zp is selected from: branched C3-C5 alkyl, C3-C10 hydroxyalkyl, C3-C10
hydroxyalkenyl, C3-C10hydroxyalkynyl, C3-Ciohydroxycycloalkyl, C4-C10 hydroxy
cycloalkenyl, and oxocycloalkyl;
ZXB is selected from: C1-C5 alkyl, C2-C5 alkenyl, C3-C5 cycloalkyl, C3-C5
cycloalkenyl, C1-C5 hydroxyalkyl, C1-C5 haloalkyl, C1-C5 alkylaryl, C1-C5
hydroxyalkylaryl, Co-C5 alkyl-CO2H, C0-C3 alkyl-cycloalkyl-CO2H, Co-C3
alkyl(cycloalkyl)C(0)NHS02Me, C0-C3 alkyl(cycloalkyl)C(O)NH-heteroaryl, Co-C3
alkyl(cycloalkyl)NHSO2(Ci-C5 alkyl), C0-C5 alkyl-N(R40)(R41), -X-(C,-C5 alkyl),
-X-(CrC5 alkenyl), -X-(C3-C5 cycloalkyl), -X-(C3-CS cycloalkenyl), -X-(C,-C5
haloalkyl), -X-(C,-C5 hydroxyalkyl), -X-(C,-C5 alkylaryl), -X(OC,-CS alkyl),
-XN(R40)(R41), -XN(R40)aryl, -N(CH3)(OCH3), -N(OH)(CH3), -N(R42)-(C|-C5
alkyl)CO2H, -N(R42)-(C,-C5 alkyl)C(O)(C|-C5 alkyl), -N(R42)-(C,-C5 alkyl)C(O)(OC|-
C5 alkyl), -N(R42)-SO2-(C!-C5 alkyl), -NR(42)-S(O)-(Ci-C5 alkyl), -P(O)-(OC,-C5
alkyl)2, heteroalkyl, heteroaryl, and -N=C(R40)N(R40)(R41);
R42 is selected from: H, C1-C3 alkyl; and C|-C3 haloalkyl;
X is selected from: O, C(O), C(S), S(O), and SO2;
provided that RB is substituted at either the 6 or 7 position of the benzoxazole
ring, except that RB is substituted only at the 7 position of the benzoxazole ring when ZXB
is at the 6 position.; and
provided that -(LXB)-ZXB is substituted at either the 5 or 6 position of the
benzoxazole ring; and
provided that RB is substituted at either the 6 or 7 position of the benzooxazole
ring, except that RB is substituted only at the 7 position of the benzoxazole ring when the
group -(LXB)-ZXB is at the 6 position.; and
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provided that RB' is substituted at either the 4 or 5 position of the benzoxazole
ring, except that RB' is substituted only at the 5 position of the benzoxazole ring when
the group -(LXB)-ZXB is at the 6 position of the phenyl ring; and
provided that RP is substituted at either the 2, or 5 or 6 position of the phenyl ring;
or a pharmaceutically acceptable salt, solvate, prodrug, enantiomer, racemate,
diastereomer or mixture of diastereomers thereof.
It will be understood by those skilled in the art that the individual groups listed
herein for the divalent linkers, (Lpi), (LR), and (LXB)» can be attached at either end to the
benzoxazole nucleus. For example, for the linking group, -N(R40)-C(O)-, either the
nitrogen can be attached to the benzoxazole nucleus or, alternatively, the carbonyl carbon
can be attached to the benzoxazole nucleus.
In preferred embodiments, compounds of the invention include the compounds of
Formula I having as preferred substituents;
R and R' are independently methyl or ethyl;
RP is hydrogen or methyl;
RP3 and RN are independently hydrogen, methyl, ethyl, -O-methyl, or
cyclopropyl;
(Lp1) is a bond;
(LP2) is a bond, -CH2-, -CH(OH)-, or-C(Me)OH-;
(LXB)is a bond,-C(O)-, -C(O)NH-, or -C(O)N(Me)-
Zpis 1,1-dimethylethyl, 1-hydroxycyclopentyl, 1-hydroxycyclohexyl, 3-ethyl-3-
hydroxypentyl, 3-ethyl-3-hydroxypentenyl, and 3-ethyl-3-hydroxypentynyl;
ZXB is -CO2H, -CO2(R40), -N(R40)(R41), NH-C(Me)(OH)-C(O)OH,
-C(O)NMe-CH2-C(O)OH, -C(O)NMe-CH2-C(O)OMe, -C(O)NMe-CH2-C(O)OEt,
-C(O)NMe-CH2-C(O)OiPr, -C(O)NMe-CH2-C(O)tBu, -cycloalkyl-C(0)OH,
-C(O)NMe-C(Me)2-C(O)OH, -C(O)N(R40)S(O)(R42), -C(O)N(R40)SO2R42,
-C(O)-N(R40)-5-tetrazolyl, -C(O)N(R40)-(C,-C5 alkyl)-S(O)R42, -C(O)N(R40)-(C,-C5
alkyl)-S(O)2R42, and -CH2CO2H.
Particularly preferred compounds of the invention and salts and prodrug
derivatives are represented by formulae Cl to C16 as follows:
Cl)
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where Rl is H, Me, or Et; R2 is H or Me; R3 is H, Me or Et; and R4 is H or Me.
Particularly preferred compounds include compounds representated by formulae C1-C16
where Rl is Me or Et; and R2, R3, R4 individually are H or Me.
EXAMPLES
General Experimental Conditions:
The starting material/intermediate is the compound from the immediate preceding
experimental unless otherwise indicated.
All reactions are performed under nitrogen/argon atmosphere, in a stirred reaction
vessel, and at room temperature unless indicated otherwise.
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Unless otherwise indicated, the notation that "organic layer is MgSO4/Na2SO4
dried" " dryed over MgSO4/Na2SO4- is defined as swirling or stirring the solution with a
dessicant (MgSO4 and/or Na2SO4) 5-15 m, then filtering off the dessicant to give an
anhydrous filtrate.
For analogous multi-step reaction procedures, the yield is given either for the
ultimate step or overall multi-steps as indicated.
Solutions are "concentrated" at a range of 25-75 °C with reduced pressure (0.05 to 1
mm).
Unless otherwise indicated, "the residue is chromatographed" is defined as silica
gel chromatography of residue with moderate nitrogen pressure (flash chromatography)
or a medium pressure chromatography systems using a silica gel to crude product ratio of
-10-100.
For HPLC, the conditions listed are for the analytical trace only. For Preparative
HPLC, the eluent is similar to analytical HPLC eluent.
Thin layer chromatography is performed with silica gel plates with UV and/or
appropriate staining solution.
NMR spectra are obtained with either 300 or 400 mHz spectrometer.
NMR data is listed to denote spectrum is consistent with assigned structure.
"NMR" notation without data denotes spectrum is consistent with assigned
structure.
HRMS - high resolution mass spectrum
ES-MS - electrospray mass spectrum
Abbreviations:
Aq - aqueous
d-day
eq - equivalent
h - hour
m - minute
satd - saturated
disp - dispersion
quant - quantitative
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it for retention time (both small caps to minimize confusion with RT)
RT - room temperature
TABLE 1
Chemical Terms
Term Definition Term Definition
BF3-OEt2 boron trifluoride etherate MeOH methanol
BnBr benzyl bromide NMO 4-methylmorpholine
N-oxide
CH2C12 Dichloromethane NMP N-methylpyrrolidin-
2-one
DMAP 4-(dimethylamino)pyridine Na-S-R3 sodium
alkylmercaptide
DMF N,N-dimethylformamide PBr3 phosphorus
tribromide
DMSO Dimethylsulfoxide Pd(DPPF) palladium
dichloro[l,l'-
bis(diphenylphosphin
o)ferrocene
DPPB 1,4-bis(diphenylphosphino) Pd(OAc)2 palladium (II) acetate
butane
DPPF dichloro[l,l'- Pd(TPP)4 palladium
bis(diphenylphosphino) tetrakistriphenylphos
ferrocene phine
EDCI 3-Ethyl-l-[3-(dimethylamino) Pd-C palladium on carbon
propyljcarbodiimide
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Term Definition Term Defmition
hydrochloride
EEDC Diethyl cyanamide Pd-C/H2 palladium on carbon
with hydrogen
pressure
EtMgBr ethyl magnesium bromide pTSA para-toluenesulfonic
acid
EtOAc ethyl acetate Pyr pyridine
EtOH Ethanol Red-Al sodium bis(2-
methoxyethoxy)alumi
num hydride
H2 hydrogen pressure R2MgBr alkyl magnesium
bromide
H2NCH2CO methyl glycinate R3MgBr alkyl magnesium
2Me bromide
Hept Heptane R5MgBr alkyl magnesium
bromide
Hex Hexanes R3S(O)2C1 alkylsulfonyl chloride
HN(OMe)Me N-methyl-O-methyl R2S(O)2N alkyl sulfonamide
hydroxylamine H2
HNMe2 dimethyl amine TBSC1 terf-butyldimethy
lsilyl chloride
HATU 0-(7-azabenzotriazol-1 -yl)- tBuC(O)C 1 -bromopinacolone
N,N,N',N'-tetramethyl H2Br-
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Term Definition Term Definition
uronium hexafluorophosphate
HOAT 7-aza-l-hydroxy benzotriazole Tf20 triflic anhydride
HOBT 1-hydroxybenzotriazole TFA trifluoroacetic acid
K2CO3 potassium carbonate THF tetrahydrofuran
LAH lithium aluminum hydride Ti(OiPr)4 titanium
tetraisopropoxide
LiHMDS lithium hexamethyl disilazide TMS- trimethylsilyl
acetylene acetylene
Lindlar Pd-CaCO3-PbO TPAP tetrapropylammoniu
catalyst m perruthenate
mCPBA meta-chloroperbenzoic acid Zn(OTf)2 zinc trifluoro
methane sulfonate
TPA 12-0-tetradecanoyl 13-acetate PHA Phytohemagglutinin
(Sigma) (Sigma)
TEA Triethylamine NMM N methylmorpholine
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General Procedures

Scheme I.
A 2-substituted-4-iodophenol is protected with a benzyl halide in base, such
as, potassium carbonate in a polar aprotic solvent, e.g., actetone or acetonitrile from
room temperature to the reflux temperature of the reaction mixture to give the benzyl
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protected phenol intermediate. This is coupled in the presence of a palladium catalyst
to the alpha-anion of an alpha-alkyl alkanoate using LiHMDS from 100 to 160 °C. to
give the ester A. The ester A is saponified with lithium, potassium, or sodium
hydroxide in an alkanol from room temperature to the reflux temperature of the
mixture to give the acid B. Acid B is converted to the acid halide, e.g., with phosgene
or phosgene/DMF and reacted with a substituted o-hydroxyaniline in the presence of
base, e.g., TEA to give the carboxanilide C. The carboxanilide C is dehydrated, e.g.,
with acid/toluene at the reflux temperature of the mixture to give the benzoxazole D.
Benzyl protection is removed from benzoxazole D by hydrogenation with a palladium
catalyst, e.g., Pd-C to give the benzoxazole E. The free hydroxyl of the benzoxazole
E. is alkylated with an alpha-halo ketone (z-C(O)CH2hal, where z is an alkyl group or
a substituted alkyl group) in base, e.g., potassium carbonate in a polar aprotic solvent
such as, acetone or acetonitrile from room temperature to the reflux temperature of the
mixture to give the alkylated benzoxazole F. Saponification of the benzoxazole F
with lithium, potassium, or sodium hydroxide in an alkanol from room temperature to
the reflux temperature of the mixture gives the acid G. Acid G is reduced with
lithium or sodium borohydride or cyanoborohydride in an alkanol or THF to give the
carbinol H. Both acids G and H, as is well known in the art, are coupled to primary or
secondary amines using, e.g., EDC to produce carboxamides such as I or the carbinol
derivative of I.

WO 2006/069154 PCT/US2005/046361

Scheme II.
Carbinol H is coupled with amino acid ester J, using common coupling
agents, such as, EDCI, HOBT, and N-methylmorpholine to give amide ester K.
Coupling of carbinol H with a cyclic amino acid ester J (R"" and R"" to form ring)
gives the corresponding cyclic amide-ester K. Amide ester K is treated with an alkali
hydroxide and an alkanol to give amide acid L.

WO 2006/069154 PCT/US2005/046361

Scheme III.
Carbinol H is coupled with alkylsulfonamide, EDCI, and DMAP to give acylsulfonamide
M. Carbinol H is coupled with 5-aminotetrazole, EDCI, and DMAP to give
25

WO 2006/069154 PCT/US2005/0-I6361
acylaminotetrazole N. Carbinol H is reacted with formamide and NaOMe at 100 °C to
produce amide O. Amide O is reacted with Et3N, 2-chloro-l,3-dimethylimidazolinium
hexafluorophosphate, and TFA to afford nitrile P. Nitrile P is reacted with Bu3SnN3 at 80
°C to give tetrazole Q.
Examples
Example 1. Preparation of 2-{l-[4-(3,3-dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-
ethyl-propyl} -benzooxazole-6-carboxylic acid

A mechanically stirred mixture of 4-iodo-2-methylphenol (1.62 moles; 391 g),
cesium carbonate (1.99 moles; 650 g), and 1.75 L of acetone is treated with benzyl
bromide (1.70 moles; 203 mL; 291 g) over 15 m. The reaction mixture was stirred for 21
h at RT and filtered. The filter cake is washed with 1L of acetone, and the combined
filtrates are concentrated. _The crude semi-solid is recrystallized from pentane to give 475
grams (90%) of the desired product as a white solid. 'H NMR (CDC13) 8: 7.40 (m, 7H),
6.64 (d, J = 8.6 Hz, 1H), 5.06 (s, 2H), 2.24 (s, 3H).
B. 2-(4-Benzyloxy-3-methyl-phenyl)-2-ethyl-butyric acid methyl ester
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WO 2006/069154 PCT/US2005/046361

To a mixture of l-benzyloxy~4-iodo-2-methyl-benzene (494 mmoles; 160 g) and
lithium bis(trimethylsilyl)amide (1.20 moles; 200 g) in 250 ml of toluene at 0-5 °C is
added a solution of 2-ethyl-butyric acid methyl ester (988 mmoles; 129 g, Synthesis, 1985
(3), 320) in 250 ml of toluene over 30 m, causing the reaction to exotherm to 18 C. The
cloudy yellow solution is allowed to warm to RT and stir for 20 m. Tri-tert-
butylphosphine (4.94 mmoles; 1.30 mL; 1.00 g) in 200 ml of toluene and
bis(dibenzylideneacetone)palladium (7.90 mmoles; 4.54 g) are added sequentially, and
the dark mixture is stirred at ambient temperature for 62 h. The mixture is diluted
with 1L of EtOAc, filtered through a bed of Hyflo, and rinsed with another 1L of EtOAc.
The Filtrate is concentrated. The dark orange oil (~200g) is purified by flash
chromatography (10% EtOAc/hexanes, 1 kg of silica) to give the title compound as a
light orange oil (72.4 g). The mixed fractions are combined and re-subjected to the
same chromatography conditions to give the another batch of title compound as a yellow
oil (50.6 g). 'H NMR (CDC13) 5 7.40 (m, 5H), 7.02 (m, 2H), 6.83 (d, J = 9.2 Hz, 1H),
5.06 (s, 3H), 3.64 (s, 3H), 2.27 (s, 3H), 2.02 (m, 4H), 0.73 (t, J = 7.4 Hz, 6H).
C. 2-(4-Benzyloxy-3-methyl-phenyl)-2-ethyl-butyric acid

To a mixture of 2-(4-benzyloxy-3-methyl-phenyl)-2-ethyl-butyric acid (265
mmoles; 86.4 g), 860 ml of 95% ethanol, and 300 ml of water is added potassium
hydroxide (2.05 moles; 115 g). The cloudy yellow solution is heated at 70 °C overnight.
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WO 2006/069154 PCT/US2005/046361
The mixture is concentrated, and the residue is partitioned between 1.5 L of MTBE
and 1.5 Lof IN HC1. The organic layer is washed with 1 L of IN HC1, dried over
MgSO4, and concentrated. The crude product (-80 g) was slurried in hexanes (350 ml).
After stirring for 1 h, the solid was filtered, washed with hexanes, and dried in vacuo at
35 °C to give 57.2 g (69%) of the title compound as a white solid. 'H NMR (CDC13) 5
7.38 (m, 5H), 7.09 (m, 2H), 6.84 (d, J = 9.2 Hz, 1H), 5.06 (s, 2H), 2.28 (s, 3H), 2.04 (m,
4H), 0.77 (t, 7 = 7.4 Hz, 6H).
D. 4-[2-(4-Benzyloxy-3-methyl-phenyl)-2-ethyl-butyrylamino]-3-hydroxy-benzoic acid
methyl ester

A solution of 2-(4-benzyloxy-3-methyl-phenyl)-2-ethyl-butyryl acid (5.20 g, 16.6
mmol) in CH2C12 (50 mL) at 0 °C is treated with (COC1)2 (6.34 g, 49.9 mmol), followed
by addition of DMF (0.2 mL). The reaction mixture is stirred for 10 m and the cooling
bath is removed. The mixture is continued to stir for 2 h at RT and concentrated to
intermediate 2-(4-benzyloxy-3-methyl-phenyl)-2-ethyl-butyryl chloride (5.40 g, 98%).
The solution of the acid chloride (5.40 g, 16.3 mmol) in CH2C12 (100 mL) is
added 4-amino-3-hydroxy-benzoic acid methyl ester (3.27 g, 19.6 mmol). The mixture is
added TEA (6.90 ml, 48.9 mmol) and DMAP (100 mg, 0.82 mmol) and stirred at RT for
2 h. The reaction is quenched with water (100 mL) and the aqueous layer is extracted
with EtOAc (2 x 50 mL). The combined organic layers are dried over Na2SO4,
concentrated, purified on column chromatography (25% EtOAc/Hex) to afford the title
compound (5.30 g, 70%). MS (ES) m/e: 462.3 (M+l), 460.2 (M-l)
E. 2-[l-(4-Benzyloxy-3-methyl-phenyl)-l-ethyl-propyl]-benzooxazole-6-carboxylic acid
methyl ester
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WO 2006/069154 PCT/US2005/046361

A solution of 4-[2-(4-benzyloxy-3-methyl-phenyl)-2-ethyl-butyrylamino]-3-
hydroxy-benzoic acid methyl ester (2.15 g, 4.66 mmol) in toluene (50 mL) is treated
with TsOH-H2O (443 mg, 2.33 mmol). The reaction is heated to 160 °C for 60 m.
The reaction mixture is cooled down, and toluene is removed under vacuum. The
residue is purified by column chromatography (10% EtOAc/Hex) to give the title
compound as an oil (1.50 g, 72%) MS (ES) m/e: 444.2 (M+l).
F. 2-[l-Ethyl-l-(4-hydroxy-3-methyl-phenyl)-propyl]-benzooxazole-6-carboxylic acid
methyl ester.

A solution of 2-[l-(4-benzyloxy-3-methyl-phenyl)-l-ethyl-propyl]-
benzooxazole-6-carboxylic acid methyl ester (1.50 g, 3.38 mmol) in MeOH (20 mL)
is added a slurry of Pd-C (150 mg, 10%) in THF (20 mL) at RT. The resulting
mixture is stirred under hydrogen balloon pressure for 12 h. The mixture is filtered
through a pad of celite, and the filtrate is concentrated. The residue is purified with
20% EtOAc/Hex to afford the title compound (1.20 g, 100%). H-NMR (ppm, CDC13)
5: 8.11 (1 H, s), 8.03 (1 H, dd, 7=1.8, 8.4 Hz), 7.73 (1 H, d, 7=8.4 Hz), 6.97 (1 H, d,
7=2.2 Hz), 6.92 (1 H, dd, 7=2.2, 8.4 Hz), 6.70 (1 H, d, 7=8.4 Hz), 3.93 (3 H, s), 2.40
(2 H, q, 7=7.5 Hz), 2.30 (2 H, q, 7=7.5 Hz), 2.20 (3 H, s), 0.76 (6 H, t, 7=7.5 Hz).
G. 2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-ethyl-propyl}-
benzooxazole-6-carboxylic acid methyl ester
29

WO 2006/069154 PCT/US2005/046361

2-[ 1 -Ethyl-1 -(4-hydroxy-3-methyl-phenyl)-propyl]-benzooxazole-6-
carboxylic acid methyl ester (1.20 g, 3.38 mmol) in acetone (40 mL) is treated with
1-bromopinacolone (0.73 g, 4.06 mmol) and K2CO3 (0.93 g, 6.76 mmol). The
suspension is stirred at RT for 4 h. The mixture is filtered, and the filtrate is
concentrated. The residue is purified using silica gel column chromatography (15%
EtOAc/Hex) to give the title compound as a pale yellow oil (1.50 g, 98%).
H-NMR (ppm, CDC13) 5: 8.14 (1 H, d, 7=2.4 Hz), 8.07 (1 H, dd, 7=1.2, 8.4 Hz), 7.78 (1
H, d, 7=8.4 Hz), 7.05 (1 H, d, 7=1.6 Hz), 7.00 (1 H, dd, 7=2.4, 8.4 Hz), 6.56 (1 H, d,
7=8.4 Hz), 4.87 (2 H, s), 3.96 (3 H, s), 2.40 (2 H, q, 7=7.5 Hz), 2.30 (2 H, q, 7=7.5 Hz),
2.28 (3 H, s), 1.27 (9 H, s), 0.77 (6 H, t, 7=7.5 Hz).
H. 2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-ethyl-propyl}-
benzooxazole-6-carboxylic acid.

2- {1 -[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-1 -ethyl-propyl} -
benzooxazole-6-carboxylic acid methyl ester (1.50 g, 3.32 mmol) in MeOH (10 mL)
and THF (10 mL) is treated with NaOH (2.0 M, 20.0 mL). The resulting mixture is
stirred at RT for 16 h. The mixture is concentrated, acidified with HC1 (5 N) until
pH~3, and extracted with EtOAc (100 mL,then 50 mL). The organic layer is dried
over Na2SO4,filtered, and concentrated to afford the title compound (1.40 g, 97%).
H-NMR (ppm, CDCI3) 6: 8.16 (1 H, d, 7=1.3 Hz), 8.11 (1 H, dd, 7=1.3, 8.4 Hz), 7.78 (1
H, d, 7=8.4 Hz), 7.02 (1 H, d, 7=1.8 Hz), 6.97 (1 H, dd, 7=2.2, 8.4 Hz), 6.54 (1 H, d,
7=8.4 Hz), 4.85 (2 H, s), 2.40 (2 H, q, 7=7.5 Hz), 2.30 (2 H, q, 7=7.5 Hz), 2.26 (3 H, s),
1.25 (9 H, s), 0.77 (6 H, t, 7=7.5 Hz). MS (ES) m/e: 438.2 (M+l), 436.2 (M-l).
30

WO 2006/069154 PCT/US2005/046361
Example 2. Preparation of 2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl)-l-
ethyl-propyl} -benzooxazole-6-carboxylic acid amide

A solution of 2-{ l-[4-(3,3-dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-ethyl-
propyl)-benzooxazole-6-carboxylic acid (150 mg, 0.343 mmol) in CH2CI2 (5.0 mL) is
treated with DMAP (125 mg, 1.03 mmol) and EDC (99 mg, 0.514 mmol). The mixture is
stirred for 15 m at RT before the addition of aqueous ammonium hydroxide (1.0 mL,
30%). The reaction is stirred for 18 h and quenched with aqueous NH4CI (5.0 mL). The
organic layer is loaded on silica gel column and purified with 50% EtOAc/Hex to afford
the title compound (40 mg, 27%). MS (ES) m/e: 437.3 (M+l).
Example 3. Preparation of 2-{ l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-
ethyl-propyl}-benzooxazole-6-carboxylic acid dimethylamide

2- {1 -[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-1 -ethyl-propyl} -
benzooxazole-6-carboxylic acid (150 mg, 0.343 mmol) in CH2CI2 (5.0 mL) is treated with
DMAP (125 mg, 1.03 mmol) and EDC (99 mg, 0.514 mmol). The mixture is stirred for
15 m at RT, and dimethylamine hydrochloride (42 mg, 0.514 mmol) is added. The
reaction is stirred for 18 h and quenched with aqueous NH4CI (5.0 mL). The organic
layer is loaded onto a silica gel column and purified with 50% EtOAc/Hex to afford the
title compound (125 mg, 79%). MS (ES) m/e: 465.3 (M+l).
Example 4. Preparation of [(2-{ l-[4-(3,3-dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-
ethyl-propyl }-benzooxazole-6-carbonyl)-amino]-acetic acid
31

WO 2006/069154 PCT/US2005/046361

2- {1 -[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-1 -ethyl-propyl} -
benzooxazole-6-carboxylic acid (150 mg, 0.343 mmol) in CH2CI2 (5.0 mL) is treated
with DMAP (125 mg, 1.03 mmol) and EDC (99 mg, 0.514 mmol). The mixture is
stirred for 15 m at RT, and glycine methyl ester hydrochloride (64 mg, 0.514 mmol) is
added. The reaction is stirred for 18 h and quenched with NH4CI (5.0 mL). The
organic layer is loaded onto a silica gel column and purified with 20-50% EtOAc/Hex
to afford the intermediate amide ester.
The intermediate is dissolved in methanol (2.0 mL) and THF (2.0 mL) and
treated with NaOH (2.0 M, 5.0 mL). The resulting mixture is stirred at RT for 3 h.
The mixture is concentrated, acidified with HC1 (1 N) to pH~3, and extracted with
EtOAc (2 x 20 mL). The organic layer is dried over Na2SO4 and concentrated to
afford the title compound (95 mg, 56%). MS (ES) m/e: 495.2 (M+l), 493.3 (M-l).
32
Example 5. Preparation of 2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-
ethyl-propyl} -benzooxazole-5-carboxylic acid


WO 2006/069154 PCT/US2005/046361
A solution of 2-(4-benzyloxy-3-methyl-phenyl)-2-ethyl-butyryl acid (4.60 g, 14.7
mmol) in CH2C12 (100 mL) at 0 °C is treated with (COC1)2 (6.73 g, 35.3 mmol), followed
by addition of DMF (0.2 mL). The reaction mixture is stirred for 10 m and the cooling
bath is removed. The mixture is continued to stir for 2 h at RT and concentrated to 2-(4-
benzyloxy-3-methyl-phenyl)-2-ethyl-butyryl chloride (5.40 g, 98%).
The solution of the acid chloride (5.40 g, 16.3 mmol) in CH2C12 (100 mL) is
added 3-amino-4-hydroxy-benzoic acid methyl ester (2.95 g, 17.7 mmol). The mixture is
added TEA (6.18 ml, 44.1 mmol) and DMAP (100 mg, 0.82 mmol) and stirred at RT for
2 h. The reaction is quenched with water (100 mL) and the aqueous layer is extracted
with EtOAc (2 x 50 mL). The combined organic layers are dried over Na2SC>4,
concentrated, purified on column chromatography (25% EtOAc/Hex) to afford the title
compound (5.80 g, 86%). MS (ES) m/e: 462.3 (M+l), 460.2 (M-l)
B. 2-[l-(4-Benzyloxy-3-methyl-phenyl)-l-ethyl-propyl]-benzooxazole-5-carboxylicacid
methyl ester

3-[2-(4-Benzyloxy-3-methyl-phenyl)-2-ethyl-butyrylamino]-4-hydroxy-benzoic
acid methyl ester (5.80 g, 12.6 mmol), TsOH-H2O (478 mg, 2.51 mmol) in toluene (100
mL) are reacted analogous to Example 1, step E to give the title product (5.08 g, 91%).
MS (ES) m/e: 444.2 (M+l).
C. 2-[l -Ethyl- l-(4-hydroxy-3-methyl-phenyl)-propyl]-benzooxazole-5-carboxylic acid
methyl ester (PF1-A05244-036A)

2-[l-(4-Benzyloxy-3-methyl-phenyl)-l-ethyl-propyl]-benzooxazole-5-carboxylic
acid methyl ester (3.28 g, 7.39 mmol) and Pd-C (300 mg, 10%) is hydrogenated
33

WO 2006/069154 PCT/US2005/046361
analogous to Example 1, step F to give the title product (2.10 g, 80%). MS (ES) m/c:
354.2 (M+l), 352.2 (M-l).
D. 2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-ethyl-propyl)-
benzooxazole-5-carboxylic acid methyl ester

2-[l -Ethyl- l-(4-hydrox y-3-methyl-phenyl)-propyl]-benzooxazole-5-
carboxylic acid methyl ester (2.10 g, 5.94 mmol) and 1-bromopinacolone (1.59 g,
8.87 mmol) and K2CO3 (2.04 g, 14.8 mmol) are reacted analogous to Example 1, step
G to give the title compound as a pale yellow oil (2.55 g, 95%). H-NMR (ppm,
CDCI3) 8: 8.43 (1 H, d, 7=1.3 Hz), 8.01 (1 H, dd, 7=1.8, 8.8 Hz), 7.42 (lH,d, 7=8.4
Hz), 7.01 (1 H, d, 7=2.2 Hz), 6.96 (1 H, dd, 7=2.2, 8.4 Hz), 6.51 (1 H, d, 7=8.8 Hz),
4.84 (2 H, s), 3.95 (3 H, s), 2.38 (2 H, q, 7=7.5 Hz), 2.32 (2 H, q, 7=7.5 Hz), 2.25 (3
H, s), 1.25 (9 H, s), 0.76 (6 H, t, 7=7.5 Hz).
E. 2-{ 1 -[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-ethyl-propyl}-
benzooxazole-5-carboxylic acid

2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-ethyl-propyl}-
benzooxazole-5-carboxylic acid methyl ester (2.55 g, 5.65 mmol) is hydrolyzed
analogous to Example 1, step H to give the title compound as a pale yellow oil (2.46
g, 99%). H-NMR (ppm, CDC13) 5: 8.51 (1 H, d, 7=1.8 Hz), 8.08 (1 H, dd, 7=1.8, 8.4
Hz), 7.45 (1 H, d, 7=8.8 Hz), 7.02 (1 H, d, 7=2.2 Hz), 6.96 (1 H, dd, 7=2.2, 8.4 Hz),
6.52 (1 H, d, 7=8.8 Hz), 4.84 (2 H, s), 2.38 (2 H, q, 7=7.5 Hz), 2.32 (2 H, q, 7=7.5
Hz), 2.26 (3 H, s), 1.25 (9 H, s), 0.76 (6 H, t, 7=7.5 Hz). MS (ES) nt/e: 438.2 (M+l),
436.2 (M-l).
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WO 2006/069154 PCT/US2005/046361
Example 6. Preparation of 2-{l-Ethyl-l-[4-(2-hydroxy-3,3-dimethyl-butoxy)-3-methyl-
phenyl]-propyl}-benzooxazole-5-carboxylic acid

2-{l-[4-(3,3-Dimemyl-2-oxo-butoxy)-3-methyl-phenyl]-l-ethyl-propyl}-
benzooxazole-5-carboxylic acid (0.58 g, 1.33 mmol) in THF (30 mL) at RT is treated
with NaBH4 (100 mg, 2.65 mmol). The resulting mixture is stirred for 1 h. The
reaction is quenched with HC1 (1.0 N, 5.0 mL) and extracted with EtOAc (3 x 50
mL). The organic layer is dried over Na2SO4 and concentrated to afford the title
compound (0.58 g, 100%). MS (ES) m/e: 440.3 (M+l), 438.2 (M-l).
Example 7. Preparation of 2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-
ethyl-propyl} -benzooxazole-5-carboxylic acid amide

2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-ethyl-propyl}-
benzooxazole-5-carboxylic acid (150 mg, 0.343 mmol), DMAP (125 mg, 1.03 mmol) and
EDC (99 mg, 0.514 mmol) and aqueous ammonium hydrroxide (1.0 mL, 30%) is reacted
analogous to Example 2 to give the title product (10 mg, 7%). MS (ES) m/e: 437.3
(M+l).
35
Example 8. Preparation of 2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-
ethyl-propyl} -benzooxazole-5-carboxylic acid dimethylamide


WO 2006/069154 PCT/US2005/046361
2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl)-l-ethyl-propyl}-
benzooxazole-5-carboxylic acid (150 mg, 0.343 mmol), DMAP (125 mg, 1.03 mmol),
EDC (99 mg, 0.514 mmol), and dimethylamine hydrochloride (42 mg, 0.514 mmol) are
reacted analogous to Example 3 to give the title product (80 mg, 50%). MS (ES) m/e:
465.3 (M+l).
Example 9 Preparation of [(2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-
ethyl-propyl} -benzooxazole-5-carbonyl)-amino)-acetic acid

2-{l-[4-(3,3-Dimethyl-2-oxo-butoxy)-3-methyl-phenyl]-l-ethyl-propyl}-
benzooxazole-5-carboxylic acid (150 mg, 0.343 mmol), DMAP (125 mg, 1.03 mmol),
EDC (99 mg, 0.514 mmol), and glycine methyl ester hydrochloride (64 mg, 0.514 mmol)
are reacted and hydrolyzed analogous to Example 4 to give the title product (130 mg,
76%). MS (ES) m/e: 495.3 (M+l), 493.3 (M-l).
Compounds of the Invention - Salts, Stereoisomers. & Prodrugs:
Salts of the compounds represented by Formula I are an additional aspect of the
invention. The skilled artisan will also appreciate that the family of compounds of
Formula 1 include acidic and basic members and that the present invention includes
pharmaceutically acceptable salts thereof.
In those instances where the compounds of the invention possess acidic or basic
functional groups various salts may be formed which are more water soluble and
physiologically suitable than the parent compound. Representative pharmaceutically
acceptable salts, include but are not limited to, the alkali and alkaline earth salts such as
lithium, sodium, potassium, ammonium, calcium, magnesium, aluminum, zinc, and the
like. Sodium and potassium salts are particularly preferred. Salts are conveniently
prepared from the free acid by treating the acid in solution with a base or by exposing the
acid to an ion exchange resin. For example, a carboxylic acid substituent on the
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WO 2006/069154 PCT/US2005/046361
compound of Formula I may be selected as -CO2H and salts may be formed by reaction
with appropriate bases (e.g., NaOH, KOH) to yield the corresponding sodium and
potassium salt.
Included within the definition of pharmaceutically acceptable salts are the
relatively non-toxic, inorganic and organic base addition salts of compounds of the
present invention, for example, ammonium, quaternary ammonium, and amine cations,
derived from nitrogenous bases of sufficient basicity to form salts with the compounds of
this invention (see, for example, S. M. Berge, et al., "Pharmaceutical Salts," J. Phar. Sci..
66: 1-19 (1977)). Moreover, the basic group(s) of the compound of the invention may be
reacted with suitable organic or inorganic acids to form salts such as acetate,
benzenesulfonate, benzoate, bicarbonate, bisulfate, bitartrate, borate, bromide, camsylate,
carbonate, chloride, choline, clavulanate, citrate, chloride, chloroprocaine, choline,
diethanolamine, dihydrochloride, diphosphate, edetate, edisylate, estolate, esylate,
ethylenediamine; fluoride, fumarate, gluceptate, gluconate, glutamate, glycolylarsanilate,
hexylresorcinate, hydrabamine, bromide, chloride, hydrobromide, hydrochloride,
hydroxynaphthoate, iodide, isothionate, lactate, lactobionate, laurate, malate, maleate,
malseate, mandelate, meglumine, mesylate, mesviate, mcthylbromide, methylnitrate,
methylsulfate, mucate, napsylate, nitrate, oleate, oxalate, palmitate, pamoate,
pantothenate, phosphate, polygalacturonate, procane, salicylate, stearate, subacetate,
succinate, sulfate, tannate, tartrate, teoclate, tosylate, trifluoroacetate, trifluoromethane
sulfonate, and valerate.
Certain compounds of the invention may possess one or more chiral centers and
may thus exist in optically active forms. Likewise, when the compounds contain an
alkenyl or alkenylene group there exists the possibility of cis- and trans- isomeric forms
of the compounds. The R- and S- isomers and mixtures thereof, including racemic
mixtures as well as mixtures of cis- and trans- isomers, are contemplated by this
invention. Additional asymmetric carbon atoms can be present in a substituent group
such as an alkyl group. All such isomers as well as the mixtures thereof are intended to
be included in the invention. If a particular stereoisomer is desired, it can be prepared by
methods well known in the art by using stereospecific reactions with starting materials
which contain the asymmetric centers and are already resolved or, alternatively by
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methods which lead to mixtures of the stereoisomers and subsequent resolution by known
methods. For example, a chiral column may be used such as those sold by Daicel
Chemical Industries identified by the trademarks:
CHIRALPAK AD, CHIRALPAK AS, CHIRALPAK OD, CHIRALPAK OJ,
CHIRALPAK OA, CHIRALPAK OB, CHIRALPAK OC, CHIRALPAK OF,
CHIRALPAK OG, CHIRALPAK OK, and CHIRALPAK CA-1.
By another conventional method, a racemic mixture may be reacted with a single
enantiomer of some other compound. This changes the racemic form into a mixture of
diastereomers. These diastereomers, because they have different melting points, different
boiling points, and different solubilities can be separated by conventional means, such as
crystallization.
Prodrugs are derivatives of the compounds of the invention which have
chemically or metabolically cleavable groups and become by solvolysis or under
physiological conditions the compounds of the invention which are pharmaceutically
active in vivo. Derivatives of the compounds of this invention have activity in both their
acid and base derivative forms, but the acid derivative form often offers advantages of
solubility, tissue compatibility, or delayed release in a mammalian organism (see,
Bundgard, H., Design of Prodrugs. pp. 7-9, 21-24, Elsevier, Amsterdam 1985). Prodrugs
include acid derivatives well known to practitioners of the art, such as, for example, esters
prepared by reaction of the parent acidic compound with a suitable alcohol, or amides
prepared by reaction of the parent acid compound with a suitable amine. Simple aliphatic
or aromatic esters derived from acidic groups pendent on the compounds of this invention
are preferred prodrugs. In some cases it is desirable to prepare double ester type prodrugs
such as (acyloxy) alkyl esters or ((alkoxycarbonyl)oxy)alkyl esters. Particularly preferred
esters to use as prodrugs are; methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl,
morpholinoethyl, and N,N-diethylglycolamido.
N,N-diethylglycolamido ester prodrugs may be prepared by reaction of the
sodium salt of a compound of Formula I (in a medium such as dimethylformamide) with
2-chloro-N,N-diethylacetamide (available from Aldrich Chemical Co., Milwaukee,
Wisconsin USA; Item No.25,099-6).
Morpholinylethyl ester prodrugs may be prepared by reaction of the sodium salt of
a compound of Formula I (in a medium such as dimethylformamide) 4-(2-
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WO 2006/069154 PCT/US2005/046361
chloroethyl)morpholine hydrochloride (available from Aldrich Chemical Co., Milwaukee,
Wisconsin USA, Item No. C5.220-3). For example, prodrugs may be prepared by
reaction of the sodium salt for a compound of Formula 1 with;

Also, lower alkyl (viz., C1-C8) ester prodrugs may be prepared by conventional
means such as reacting the sodium or potassium salt (derived by forming the salt of any
acidic compound of the invention; viz., reaction of a base such as KOH with an acidic
group such as -CO2H) of a compound of Formulae I with an alkyl iodide such as methyl
iodide, ethyl iodide, n-propyl iodide, isopropyl iodide.
Pharmaceutical Formulations containing the Novel Compounds of the Invention:
Pharmaceutical formulations of the invention are prepared by combining (e.g.,
mixing) a therapeutically effective amount of the compound of the invention
(compounds of Formula I) together with a pharmaceutically acceptable carrier or
diluent. The present pharmaceutical formulations are prepared by known procedures
using well-known and readily available ingredients.
In making the compositions of the present invention, the compounds of the
invention will usually be admixed with a carrier, or diluted by a carrier, or enclosed
within a carrier which may be in the form of a capsule, sachet, paper or other
container. When the carrier serves as a diluent, it may be a solid, semi-solid or liquid
material which acts as a vehicle, or can be in the form of tablets, pills, powders,
lozenges, elixirs, suspensions, emulsions, solutions, syrups, aerosols (as a solid or in a
liquid medium), or ointment, containing, for example, up to 10% by weight of the
39

compound. The compounds of the present invention are preferably formulated prior to
administration.
The compounds of the invention may also be delivered by suitable formulations contained in
a transderm patch. Alternatively, the compounds of the invention may be delived to a patient
by sublingual administration.
For the pharmaceutical formulations any suitable carrier known in the art can be used. In
such a formulation, the carrier may be a solid, liquid, or mixture of a solid and a liquid. Solid
form formulations include powders, tablets and capsules. A solid carrier can be one or more
substances which may also act as flavoring agents, lubricants, solubilisers, suspending
agents, binders, tablet disintegrating agents and encapsulating material.
A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a
compound of the present invention or a pharmaceutically acceptable salt thereof is found to
show surprising properties. Therefore, a pharmaceutical composition of the present
invention is found to be synergistic.
Tablets for oral administration may contain suitable excipients such as calcium carbonate,
sodium carbonate, lactose, calcium phosphate, together with disintegrating agents, such as
maize, starch, or alginic acid, and/or binding agents, for example, gelatin or acacia, and
lubricating agents such as magnesium stearate, stearic acid, or talc.
In powders the carrier is a finely divided solid which is in admixture with the finely divided
Active lingredient. In tablets a compound of the invention 1 is mixed with a carrier having
the necessary binding properties in suitable proportions and compacted in the shape and size
desired. The powders and tablets preferably contain from about 1 to about 99 weight percent
of the compound of this invention. Suitable solid carriers are magnesium carbonate,
magnesium stearate. talc, sugar lactose, pectin, dextrin, starch, gelatin, tragacanth, methyl
cellulose, sodium carboxymethyl cellulose, low melting waxes, and cocoa butter. Sterile
liquid form formulations include suspensions, emulsions, syrups and elixirs.
The Active Ingredient may be dissolved or suspended in a pharmaceutically acceptable
carrier, such as sterile water, sterile organic solvent or a mixture of both. The compounds
can often be dissolved in a suitable organic solvent, for instance aqueous propylene glycol.
Other compositions can be made by dispersing the finely divided compounds of the
invention in aqueous starch or sodium carboxymethyl cellulose solution or in a suitable oil.
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WO 2006/069154 PCT/US2005/046361
Methods of Using the Compounds of the Invention:
Many disease states are benefited by treatment with the compounds of Formula I
include, but are not limited to: disease states characterized by: abnormal calcium
regulation, abnormal cell proliferation, abnormal cell differentiation, abnormal immune
response, abnormal dermatological conditions, neurodegenerative condition,
inflammation, vitamin D sensitivity, and/or hyperproliferative disorders.
Specific disease states benefited by treatment of the compounds of Formula I
include, but are not limited to: Acne, Actinic keratosis, Alopecia, Alzheimer's disease,
Benign prostatic hyperplasia, Bladder cancer, Bone maintenance in zero gravity, Bone
fracture healing, Breast cancer, Chemoprovention of Cancer, Crohn's disease, Colon
cancer, Type 1 diabetes. Host-graft rejection, Hypercalcemia, Type II diabetes. Leukemia,
Multiple sclerosis, Myelodysplastic syndrome, Insufficient sebum secretion,
Osteomalacia, Osteoporosis, Insufficient dermal firmness, Periodontal disease,
Insufficient dermal hydration, Psoriatic arthritis. Prostate cancer. Psoriasis, Renal
osteodystrophy, Rheumatoid arthritis, Scleroderma, Skin cancer, Systemic lupus ,
rythematosus, Skin cell damage from mustard vesicants,,Ulcerative colitis, Vitiligo, and
Wrinkles.
Particularly preferred is the treatment of psoriasis and/or osteoporosis by
administration to a mammal (including a human) of a therapeutically effective amount of
compounds of Formula I. By "pharmaceutically effective amount" it is meant that
quantity of pharmaceutical agent corresponding to Formula I which prevents, removes or
reduces the deleterious effects of a disease state in mammals, including humans.
The specific dose of a compound administered according to this invention to
obtain therapeutic or prophylactic effects will, of course, be determined by the particular
circumstances surrounding the case, including, for example, the compound administered,
the route of administration and the condition being treated. Typical daily doses will
contain a pharmaceutically effective amount typically in the range of from about 0.0001
mg/kg/day to about 50 mg/kg/day of body weight of an active compound of this
invention. Preferably the dose of compounds of the invention will be from 0.0001 to 5
mg/kg/day of body weight.
Preferably compounds of the invention or pharmaceutical formulations
containing these compounds are in unit dosage form for administration to a mammal.
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WO 2006/069154 PCT/US2005/046361
The unit dosage form can be a capsule or tablet itself, or the appropriate number of any
of these. The quantity of Active Ingredient in a unit dose of composition may be varied
or adjusted from about 0.0001 to about 1000 milligrams or more according to the
particular treatment involved. It may be appreciated that it is necessary to make
routine variations to the dosage depending on the age and condition of the patient.
Dosage will also depend on the route of administration. The compounds of the
invention may be administered by a variety of routes including oral, aerosol, rectal,
transdermal, sublingual, subcutaneous, intravenous, intramuscular, and intranasal.
Particularly preferred is the treatment of psoriasis with an ointment type formulation
containing the compounds of the invention. The ointment formulation may be applied
as needed, typically from one to 6 times daily.
Treatment of psoriasis is preferably done with topical application by a
formulation in the form of a cream, oil, emulsion, paste or ointment containing a
therapeutically effective amount of a compound of the invention. The formulation for
topical treatment contains from 0.5 to 0.00005 weight percent, preferably from .05 to
0.0005 weight percent, and most preferably from 0.025 to 0.001 of a Active Ingredient.
For example, two semisolid topical preparations useful as vehicles for VDR
modulators in treatment and prevention of psoriasis are as follows:
Polyethylene Glvcol Ointment USP (p. 2495)
Prepare Polyethylene Glycol Ointment as follows:
Polyethylene Glycol 3350 400 g.
Polyethylene Glycol 400 600 g.
To make 1000 g.
Heat the two ingredients on a water bath to 65°C. Allow to cool, and stir until
congealed. If a firmer preparation is desired, replace up to 100 g of the polyethylene
glycol 400 with an equal amount of polyethylene glycol 3350.
Hydrophilic Ointment USP (p. 1216)
Prepare Hydrophilic Ointment as follows:
Methylparaben 0.25 g.
Propylparaben 0.15 g.
Sodium Lauryl Sulfate 10 g.
Propylene Glycol 120 g.
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WO 2006/069154 PCT/US2005/046361
Stearyl Alcohol 250 g.
White Petrolatum 250 g.
Purified Water 370 g.
To make about 1000 g.
The Stearyl Alcohol and White Petrolatum are melted on a steam bath, and
warmed to about 75°C. The other ingredients, previously dissolved in the water are
added, warmed to 75°C, and the mixture stirred until it congeals.
For each of the above formulations the Active Ingredient is added during the
heating step in an amount that is from 0.5 to 0.00005 weight percent, preferably from .05
to 0.0005 weight percent, and "USP" most preferably from 0.025 to 0.001 weight percent
of the total ointment weight. (Source: - United States Pharmacopoeia 24, United States
Pharmacopeial Convention, 1999)
Conventional therapy for osteoporosis includes; (i) estrogens, (ii) androgens, (iii)
calcium supplements, (iv) vitamin D metabolites, (v) thiazidc diuretics, (vi) calcitonin,
(vii) bisphosphonates, (viii) SERMS, (ix) fluorides and (x) Parathyroid hormone (PTH)
(see, Harrison's Principles of Internal Medicine, 13th edition, 1994, published by McGraw
Hill Publ., ISBN 0-07-032370-4, pgs. 2172-77; the disclosure of which is incorporated
herein by reference). Any one or a combination of these conventional therapies may be
used in combination with the method of treatment using compounds of Formula I as
taught herein. For example, in a method of treating osteoporosis, the vitamin D receptor
modulator compounds of the invention may be administered separately or simultaneously
with a conventional therapy. Alternatively, the vitamin D receptor modulator compounds
of the invention may be combined with conventional therapeutic agents in a formulation
for treatment of osteoporosis such as set out below:
A formulation for treating osteoporosis comprising:
Ingredient (A 1): a vitamin D receptor modulator represented by
Formula (I), or a pharmaceutically acceptable salt or prodrug
derivative thereof;
Ingredient (Bl):
one or more co-agents that are conventional for treatment
osteoporosis selected from the group consisting of: estrogens,
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WO 2006/069154 PCT/US2005/046361
androgens, calcium supplements, vitamin D metabolites, thiazide
diuretics, calcitonin, bisphosphonates, SERMS, fluorides, and PTH
Ingredient (Cl): optionally, a carrier or diluent.
Typically useful formulations are those wherein the weight ratio of (Al) to (Bl) is from
10:1 to 1:1000 and preferably from 1:1 to 1:100.
Combination Therapy for Psoriasis:
Conventional therapy for psoriasis includes topical glucocorticoids, salicylic acid,
crude coal tar, ultraviolet light, and methotrexate (see, Harrison's Principles of Internal
Medicine, 13th edition, 1994, published by McGraw Hill Publ., ISBN 0-07-032370-4, pgs.
2172-77). Any one or combination of these conventional therapies may be used in
combination with the method of treatment using compounds of Formula I as taught
herein. For example, in a method of treating psoriasis, the vitamin D receptor modulator
compounds of the invention (e.g., as defined by Formula I) may be topically administered
separately or simultaneously with a conventional therapy. Alternatively, the vitamin D
receptor modulator compounds of the invention may be combined with conventional
therapeutic agents in a topically applied formulation for treatment of psoriasis such as set
out below:
A formulation for treating psoriasis comprising:
Ingredient (A2): a vitamin D receptor modulator represented by Formula
(1), or a pharmaceutically acceptable salt or prodrug derivative
thereof;
Ingredient (B2):
one or more co-agents that are conventional for treatment psoriasis
selected from the group consisting of: topical glucocorticoids,
salicylic acid, or crude coal tar.
Ingredient (C2): optionally, a carrier or diluent.
Typically useful formulations are those wherein the weight ratio of (A2) to (B2) is from
1:10 to 1:100000 and preferably from 1:100 to 1:10000.
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WO 2006/069154 PCT/US2005/046361
Experimental Results:
Table 2
Summary of Experimental Results

TestCmpd. RXR-VDRheterodimer2EC50 (nM) OCNPro moter 3EC50 (nM) Kera.Prolif.IC50(nM)4
Ex. 1 1117 376
Ex.2 73 289 >1000
Ex.3 701 1642
Ex.4 700 1174
Ex.5 37 8 >1000
Ex.6 5 36
Ex 7 177 >1000
Ex 8 117 >1000
Ex 9 150 >1000
Explanation of Table 2 column numerical superscripts:
1. Test Compound numbers refer to the products of the corresponding
Example Nos. that is, compounds within the scope of the invention.
2. The RXR-VDR heterodimerization (SaOS-2 cells) test is described in the
"Assay" section of the Description, infra.
3. The OCN Promoter test is described in the "Assay" section of the
Description, infra.
4. The keratinocyte proliferation assay is described in the "Assay" section of
the Description, infra.
Assay Methods
Use of the Assay Methods:
The evaluation of the novel compounds of the invention for osteoporosis and other
related diseases is done using a plurality of test results. The use of multiple assays is
beneficial since it is preferred that the combined properties of (i) high activity for the
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WO 2006/069154 PCT/US2005/046361
vitamin D receptor, and (ii) prevention of hypercalcemia be achieved to effect of treating
diseases, which are also aspects of this invention. Some of the tests described below are
believed related to other tests and measure related properties of compounds.
Consequently, a compound may be considered to have utility in the practice of the
invention if it meets at least one preferably two or more, if not all, of the acceptance
criteria for the above described tests.
The evaluation of die novel compounds of the invention for psoriasis is done
using the Keratinocyte Proliferation Assay in combination with other assays that measure
inhibition of IL-2 production and stimulation of IL-10 production in peripheral blood
mononuclear cells (PBMCs).
Brief Description. Utility and Acceptance Criteria for the Assay Methods:
1. The RXR-VDR heterodimerAssay:
This assay provides the VDR activity of a test compound. It is desirable to have
low EC50 values for a compound in this assay. The lower the EC50 value, the more
active the compound will be as a VDR agonist. Desired assay results are EC50 values
less than or equal to 600 nM. Preferred assay results are less than 250 nM, and most
preferably less than 150 nM.
(1) Materials and Method for RXR-VDR Heterodimerization Assay Transfection
Method: Reagents: FuGENE 6 Transfection Reagent (Roche Cat # 1 814 443);
Growth Media: D-MEM High Glucose (Gibco BRL Cat # 11054-020), 10% heat
inactivated FBS (Gibco BRL Cat # 10092-147), 1% antibiotic-antimycotic (Ab-Am);
(Gibco BRL Cat # 15240-062 ).
Cells: Grow SaOS-2 cells in T-150 cm2 culture flasks in growth media keeping the
density at 5-6 x 105 cells/ml. Passage cells 1:3 twice a week. Add Trypsin EDTA (Gibco
BRL Cat # 25300-020) and incubate. Resuspend cells in plating media and transfer into
growth media.
Wash Media: HBSS Low Glucose Without Phenol Red (Gibco BRL Cat # 14175-095),
1% Ab-Am. Plating Media: D-MEM Low Glucose Without Phenol Red (Gibco BRL Cat
46

WO 2006/069154 PCT/US2005/046361
# 11054-020), 1% Ab-Am; D-MEM; 10 % Stripped FBS (Hyclone Cat# SH3OO68.O3
Lot#AHM9371).
Transfection / Treatment Media: D-MEM Low Glucose Without Phenol Red only; T-150
cm2 culture flask: Use Corning Coastar T-150 cm2 culture flask (Cat # 430825) to grow
the cells.
Luciferase Assay Reagent: Use Steady-Glo Luciferase Reagent from Promega (Cat #
E2550) Consists of: E2533 Assay Substrate, lyopholized product and E2543 Assay
Buffer. Thaw at room temperature and store.
Cell Harvesting/Count: Aspirate media from culture flask, rinse cells with HBSS and
aspirate. Add trypsin and incubate. When cells appear detached, resuspend cells in
growth media. Transfer into a new flask with fresh growth media for passaging the cells.
Plate 96 well plates and two extra plates. Mix the cell suspension using pipette. To count
the cells using a Hematocytometer.
Plate seeding: Use plating media 10 % Stripped FBS in D-MEM Low Glucose, without
Phenol Red, 1% Ab-Am. Plate 14 plates @ 165 |il / well. In sterile flask add cell
suspension to plating media and mix. Add cells / well. Place the cells in the incubator.
Cells should be about 75 % confluent prior to transfection. DAY 2: Transfection: Step 1,
DNA and Media: Add plain DMEM media to tubes for mixing the DNA; add the
Reporter gene pFR-LUC; and add the Gal4-RXR-DEF and VP16-VDR-LBD. Step 2,
FuGENE and Media: Prepare plain DMEM media in a tubes for mixing FuGENE, add
FuGENE 6 Transfection Reagent, and mcubate. Step 3, FuGENE, DNA and Media
Complex: Add FuGENE Media complex from step 2 to DNA Media complex from step 1
and incubate. Step 4, FuGENE, DNA and Media Complex to 96 well plate: Add
FuGENE-DNA-Media complex from step 3 to each plate. Incubate.
Day 3: Dosing: Treatment preparation. Allow for transfection time.
Make a stock solution of the compounds in DMSO and vortex until all the compounds
have been dissolved. Further dilute in D-MEM (Low Glucose - without Phenol Red)
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WO 2006/069154 PCT/US2005/046361
Add compounds in quadruplicate to give desired final volume then incubate.
Day 4: Luciferase Assay: Read the plates after drug treatment. Remove part of media
from all the wells and leave remainder. Add Steady-Glo Luciferase Reagent mixture/
wells and incubate. Count each well using a Luminescence counter, Top Count NXT
by Packard preferably set a delay between plates to reduce the background.
The Caco-2 cell Co-transfection Assay:
The Caco-2 cell assay is an indicator for the undesirable condition of
hypercalcemia. This co-transfection assay is a surrogate assay for in vivo calcemic
activity of VDR ligands. It is desirable to have high EC50 values for a test compound
in this assay. The higher the EC50 values for a compound the less calcemic it will be
in vivo. Desired assay results are EC50 greater than or equal to 300 nM. Preferred
assay results are greater than 1000 nM.
Caco-2 cells, grown in phenol red free, DMEM (Invitrogen, Carlsbad, CA)
containing 10 % charcoal-stripped FBS (Hyclone, Logan, UT), are transfected with
Fugene 6 reagent (Roche Diagnostics, Indianapolis, IN). Cells (5000/well) are plated 18 h
before transfection in a 96 well plate. The cells are transfected with Gal4-responsive
reporter pFRLuc (150 ng, Stratagene, La Jolla CA) and the receptor expression vector
pGal4-VDR-LBD (10 ng), along with Fugene 6 reagent (0.2 ul/well). The DNA-Fugene
complex is formed by incubating the mixture for 30 m at room temperature. The cells are
transfected in triplicate for 5 h, and treated with various concentrations of VDR ligands
(from 0.01 nM to 10,000 nM concentration range) 18h post-transfection. The luciferase
activity is quantified using Steady-Glo reagent kit (Promega, Madison, WI) as per
manufacturer's specifications.
The OCN (osteocalcin) Promoter Assay
The OCN Promoter Assay is an indicator and marker for osteoporosis. Desired
assay results are EC50 less than or equal to 325 nM. Preferred assay results are less than
50 nM.
The activation of osteocalcin by VDR ligands is evaluated in a rat osteoblast-like
cell line RG-15 (ROS 17/2.8) stably expressing rat osteocalcin promoter fused with
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WO 2006/069154 PCT/US2005/046361
luciferase reporter gene. The stable cell lines are established as reported before
(Activation of Osteocalcin Transcription involves interaction of protein kinase A- and
Protein kinase C-dependent pathways. Boguslawski, G., Hale, L. V., Yu, X.-P., Miles, R.
R., Onyia, J. E., Santerre R. F., Chandrasekhar, S. J Biol. Chem. 275, 999-1006, 2000).
Confluent RG-15 cells maintained in DMEM/F-12 medium (3:1) containing 5% FBS, 300
pg/ml G418 and at 37°C under 5% CO2/95% air atmosphere are trypsinized (0.25%
trypsin) and plated into white opaque 96-well cell culture plates (25000 cells/well). After
24 h, cells (in DMEM/F-12 medium + 2% FBS) are treated with various concentrations of
compounds, dissolved in DMSO. The final DMSO concentration remains at 0.01% (v/v).
After 48 h treatment, the medium is removed, cells are lysed with 50 ui of lysis buffer
(From Luciferase reporter assay system, Roche Diagnostics, Indianapolis, IN) and then
assayed for luciferase activity using the Luciferase Reporter Gene Assay kit from
Boehringer Mannheim as per manufacturer's specifications.
The Mouse Hvpercalcemia Assay
The Mouse Hypercalcemia Assay is a six day hypercalcemia test for toxicity and
selectivity. Acceptable test results are levels greater than 30 |ig/kg/day. Preferred assay
results are levels greater than 300 ng/kg/day.
Weanling, virus -antibody-free, five to six weeks old female DBF mice (Harlan,
Indianapolis, IN) are used for all the studies. Animals are allowed to acclimate to local
vivarium conditions for 2 days. Mice are maintained on a 12 h light/dark cycle at 22°C
with ad lib access to food (TD 5001 with 1.2% Ca and 0.9% P, Teklad, Madison, WI) and
water. The animals then are divided into groups with 4-5 mice per group. Different
doses of test compounds prepared in 10% ethanol and 90% sesame oil, or in an aqueous
suspension of sodium lauryl sulfate and CMC (the latter formulation for acidic
compounds) are administered to mice orally via gavage for 6 days. la-25(OH)2D3
0.5u.g/kg/d was also given to one group of mice as the positive control. Serum ionized
calcium is evaluated at 6 hs after the last dosing under isoflurane anesthesia by Ciba-
Corning Ca++/PH Analyzer, (Model 634, Chiron Diagnostics Corp., East Walpole, MA).
Raw data of group differences is assessed by analysis of variance (ANOVA) using
Fisher's protected least significant difference (PLSD) where the significance level was P<
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WO 2006/069154 PCT/US2005/046361
0.05. The highest dose that did not cause hypercalcemia, as defined by the 97.5%
reference distribution of the control population, is considered "the no effect level".
The Keratinocvte Proliferation Assay
This Assay is indicative for the treatment of psoriasis. An acceptable test
result is 1C50 value of less than or equal to 300 nM. Preferred assay results are IC50
values of less than 100 nM.
KERtr cells (Human skin keratinocyte) are transformed with a retrovirus vector,
obtained from ATCC, then are plated in 96-well flat-bottomed plates (3000 cells/well) in
100 ul keratinocyte serum free medium supplemented with bovine pituitary extract in the
absence of EGF (Life Technologies, Rockville, MD) and are incubated at 37°C for two
days. The cells are treated with various concentrations of VDR ligands (ten-fold serial
dilution from 10,000 nM to 0.1 nM in triplicate), dissolved in 100 pi keratinocyte serum
free medium supplemented with bovine pituitary extract in the absence of EGF and are
incubated at 37°C for 72h. BrdU (5-bromo-2'-deoxyuridine) incorporation is analyzed as
a measure of DNA replication (Cell proliferation ELISA kit, Roche Diagnostics,
Indianapolis, IN) and absorbance is measured at 405 nm. Potency values (IC50) values
were determined as the concentration (nM) of compound that elicited a half-maximal
response.
The IL-10 induction Assay
This is an in vitro efficacy assay for psoriasis, abscess and adhesion. Psoriasis
involves both keratinocytes and immune cells. IL-10 is a unique cytokine because it is
anti-inflammatory and immunosuppressive. This assay tells us whether a VDRM is able
to function as an agonist in PBMCs (primary blood mononuclear cells) or not. A lower
EC50 value is desirable in this assay since a compound with a lower EC50 value will be a
better agonist in PBMCs. An acceptable test result is an EC50 value of less than 200 nM.
Preferred assay results are EC50 values of less than 100 nM.
Isolation of peripheral blood mononuclear cells (PBMCs):
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WO 2006/069154 PCT/US2005/046361
Collect 50 ml of human blood and dilute with media, RPMI-1640. Add diluted
blood to sterile tubes with ficol. Centrifuge the tubes. Discard the top layer and collect
the cells from middle layer. Divide all cells into four tubes and add media. Centrifuge;
aspirate off media and resuspend the cells. Collect all cells. Centrifuge at 1200 pm for 10
m. Resuspend the cells in RPMI-1640 with 2% FBS and then count cells.
Stimulation of PBMC: Prepare TPA in DMSO. Dissolve PHA in water. Plate
TPA/PHA treated PBMCs in well plates. Incubate the cells.
Treatment: Prepare all compound dilutions in plain RPMI-1640 media. Add diluted
compound and incubate. Sample Collection and assay: Remove all the cells by
centrifugation and assay the supernatant for IL-10 by immunoassay using anti-human IL-
10 antibody coated beads, as described by the manufacturer (Linco Research Inc., St.
Charles, MO).
Other Compound Assay Standards
An alternative measure of the therapeutic index (bone efficacy vs hypercalcemia) of
compounds of the invention for treatment of osteoporosis is a numerical ratio
calculated as follows:
Dose Threshold needed to induce hypercalcemia
divided by
Dose Threshold needed for bone efficacy
An alternative measure of the therapeutic index (in vivo keratinocyte
proliferation vs. hypercalcemia) of compounds of the invention for treatment of
psoriasis is a numerical ratio calculated as follows:
Dose Threshold needed to induce hypercalcemia
divided by
Dose Threshold needed to induce keratinocyte proliferation
For the above ratios. Dose Thresholds are determined from dose response curve data.
The CaTl (calcium transporter 1) Assay
The CaTl Assay is an indicator for the undesirable condition of
hypercalcemia. The higher the EC50 values for a compound the less calcemic it will
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WO 2006/069154 PCT/US2005/046361
be in vivo. Desired assay results are EC50 greater than or equal to 500 nM. Preferred
assay results are greater than 1000 nM.
Human colon carcinoma, Caco-2 cells, maintained in DMEM (high glucose with
25 mM Hepes buffer; Invitrogen, Carlsbad, CA) supplemented with 10 % FBS
(Invitrogen, Carlsbad, CA), are plated at 5500 cell per well in a 96-well plate in a total
volume of 100 fil/well. The cells are kept in the 96-well plate for 6 days to differentiate
them to small intestinal cells that express the calcium transporter, CaTl. On day 3 after
plating, old media is removed and replaced with fresh media (150 ul/well). On day 6 the
old media is removed and the cells are kept in treatment media (180 uj/well) that
contained 10 % charcoal stripped FBS (Hyclone, Logan, UT) in DMEM (low glucose,
without phenol red; Invitrogen, Carlsbad, CA). The cells are treated with various
concentrations of VDR ligands (from 0.01 nM to 10,000 nM concentration range)
prepared in treatment media (20 nl/well). Twenty hours post-treatment, total RNA is
prepared by RNeasy 96 method as described by the manufacturer (Qiagen, Valencia,
CA). The RNA is reverse transcribed and amplified for human CaTl and GAPDH
(control) messages by quantitative RT-PCR using ABI PRISM 7900HT Sequence
Detection System according to manufacturer's instructions (Applied Biosystems, Foster
City, CA). Optimized primer pairs and probes for human CaTl and GAPDH genes are
obtained commercially (Applied Biosystems, Foster City, CA). Each 20 (il quantitative
RT-PCR reaction in a 384-well Taqman PCR plate consists of forward and reverse
primers (900 nM), Taqman probe (200 nM), total RNA (4 |il form each well of the 96-
well culture plate) and 10 uJ of Taqman Universal PCR Master Mix (Roche Diagnostics,
Indianapolis, IN). Reactions are incubated at 48°C for 30 m followed by 10 m at 95°C and
subjected to 40 cycles of PCR (95°C for 15 seconds followed by 60°C for 1 m). GAPDH
is used as an internal control and its primer and probe set are obtained commercially
(Applied Biosystems, Foster City, CA).
52

We Claim:
1. A compound or a pharmaceutically acceptable salt or an ester derivative
thereof represented by Formula (I):

wherein
R and R' are independently C1-C5 alkyl, C1-C5 haloalkyl, or together R and R'
form a saturated or unsaturated cycloalkyl ring having from 3 to 8 carbon atoms;
RP3 and RB are independently selected from: hydrogen, halo, C1-C5 alkyl, C1-C5
haloalkyl, -O-C1-C5 alkyl, -S-C1-C5 alkyl, -O-C1-C5 haloalkyl, -CN, -NO2, acetyl, -S-
C1-C5 haloalkyl, C2-C5 alkenyl, C3-C5 cycloalkyl, and C3-C5 cycloalkenyl;
RP and RB' are independently selected from: hydrogen, halo. C1-C5 alkyl, C1-
C5 haloalkyl, -O-Cj-C5 alkyl, -S-C1-C5 alkyl, -O-C1-C5 haloalkyl, -CN, -NO2, acetyl, -
S-C1-C5 haloalkyl. C2-C5 alkenyl, C3-C5 cycloalkyl, or C3-C5 cycloalkenyl;
(Lpi), (Lp2), and (LXB) are divalent linking groups independently selected from the
group consisting of: a bond, -(CH2)m-C(OH)-, -(CH2)m-O-, -(CH2)m-S-, -(CH2)m-S(O)-
, -(CH2)m-S(O)2-, -(CH2)m-N(R40)-, -(CH2)m-C(R40)(R41)-, -(CH2)m-C(O)-
, -N(R40)-C(O)-, -(CH2)m-CH-CH-, and -(CH2)m-C=C-; where m is 0-5;
R40 and R41 each is independently selected from: hydrogen, C1-C5 alkyl, C1-
C5 hydroxyalkyl, C1-C5 haloalkyl, C2-C5 alkenyl, C3-C5 cycloalkyl, and C3-C5
cycloalkenyl;
53

Zp is selected from: branched C3-C5 alkyl, C3-C10 hydroxyalkyl, C3-C10
hydroxyalkenyl, C3-C10 hydroxyalkynyl, C3-C10 hydroxycycloalkyl, C4-C10 hydroxy
cycloalkenyl, and oxocycloalkyl;
ZXB is selected from: C1-C5 alkyl, C2-C5 alkenyl, C3-C5 cycloalkyl, C3-C5
cycloalkenyl, C1-C5 hydroxyalkyl, C1-C5 haloalkyl, C1-C5 alkylaryl, C1-C5
hydroxyalkylaryl, Co-C5 alkyl-CO2H, Co-C3 alkyl-cycloalkyl-CO2H, Co-C3
alkyl(cycloalkyl)C(O)NHSO2Me, C0-C3 alkyl(cycloalkyl)C(O)NH-heteroaryl, C0-C3
alkyl(cycloalkyl)NHSO2(C,-C5 alkyl), Co-C5 alkyl-N(R40)(R41), -X-(CrC5 alkyl), -X-
(C1-C5 alkenyl), -X-(C3-C5 cycloalkyl), -X-(C3-C5 cycloalkenyl). -X-(Ci-C5
haloalkyl), -X-(C,-C5 hydroxyalkyl), -X-(CrC5 alkylaryl), -X(OCi-C5
alkyl), -XN(R40)(R41), -XN(R40)aryl, -N(CH3)(OCH3), -N(OH)(CH3), -N(R42)-(C,-
C5 alkyl)CO2H, -N(R42)-(C,-C5 alkyl)C(O)(Ci-C5 alkyl), -N(R42)-(C,-C5
alkyl)C(O)(OCi-C5 alkyl), -N(R42)-SO2-(Ci-C5 alkyl), -NR(42)-S(O)-(Ci-C5 alkyl), -
P(O)-(OCi-C5 alkyl)2, heteroaryl, and -N=C(R40)N(R40)(R41);
R42 is selected from: H, C4-C3 alkyl, and C1-C3 haloalkyl;
X is selected from: O, C(O), C(S), S(O), and SO2;
provided that RB is substituted at either the 6 or 7 position of the benzoxazole
ring, except that RB is substituted only at the 7 position of the benzoxazole ring when
ZXB is at the 6 position; and
provided that -(LXB)-ZXB IS substituted at either the 5 or 6 position of the
benzoxazole ring; and
provided that RB is substituted at either the 6 or 7 position of the benzooxazole
ring, except that RB is substituted only at the 7 position of the benzoxazole ring when the
group
--(LXB)-ZXB is at the 6 position; and
provided that RB' is substituted at either the 4 or 5 position of the benzoxazole
ring, except that RB' is substituted only at the 5 position of the benzoxazole ring when
the group -(LXB)-ZXB is at the 6 position of the phenyl ring; and
provided that RP is substituted at either the 2, or 5 or 6 position of the phenyl
ring.
54

2. A compound of Claim 1, or a pharmaceutically acceptable salt or an ester
derivative thereof,
wherein
R and R' are independently methyl or ethyl;
RP is hydrogen or methyl;
RP3 and RN are independently hydrogen, methyl, ethyl, -O-methyl, or
cyclopropyl;
(Lpi) is a bond;
(LP2) is a bond, -CH2-, -CH(OH)-, or - C(Me)OH-;
(LXB) is -C(O)-, -C(O)NH-, or -C(O)N(Me)-
Zp is selected from the group consisting of: 1,1-dimethylethyl, 1-
hydroxycyclopentyl, 1-hydroxycyclohexyl, 3-ethyl-3-hydroxypentyl, 3-ethyl-3-
hydroxypentenyl, and 3-ethyl-3-hydroxypentynyl;
ZXB is selected from the group consisting of: -CO2H,- CO2(C1-
C5) -N(R40)(R41), NH-(Ci-C5alkyl)CO2H,NMe-CH2-C(O)OH. -NMe-CH2-
C(O)OMe, - NMe-CH2-C(O)OEt, - NMe-CH2-C(O)OiPr, - NMe-CH2-C(O)tBu, -
cyclopropyl-C(O)OH, - NMe-C(Me)2-C(O)OH, - N(R42)S(O)(C|-C5 alkyl), -
C(O)N(R42)SO2(C,-C1 alkyl), -N(R40)-5-tetrazolyl, - and-CH2CO2H.
3. A compound represented by formulae (Cl) to (C16) or a pharmaceutically
acceptable salt or an ester derivative thereof:
55
Cl)



56


57


58


where Rl is H, methyl or ethyl; R2 is H or Me; R3 is H, methyl or ethyl; and R4 is H or
methyl.
4. The compounds of claim 3, or pharmaceutically acceptable salts or ester
derivatives thereof, where Rl is methyl or ethyl and R2 is H or methyl.
5. The compound of claim 3 represented by the structural formula (C2) or a
pharmaceutically acceptable salt thereof.
6. A compound of claim 3 represented by the structural formula (Cl) or a
pharmaceutically acceptable salt thereof.
7. A compound of any of claims 1 to 4 wherein the ester derivative is a
methyl ester; ethyl ester; N,N-diethylglycolamido ester; or morpholinylethyl ester.
8. A compound of any of claims 1 to 4 wherein the salt counter ion is sodium
or potassium.
59

9. A pharmaceutical formulation comprising the compound of any of claims 1 to
8 or a pharmaceutically acceptable salt or ester derivative thereof, either with a
pharmaceutically acceptable carrier or diluent.
10. A formulation for treating osteoporosis comprising:
a compound of Formula I of any of claims 1 to 8, or pharmaceutically acceptable salt
or ester derivative thereof;
one or more co-agents selected from the group consisting of: estrogens, androgens,
calcium supplements, vitamin D metabolites, thiazide diuretics, calcitonin,
bisphosphonates, SERMS, fluorides; and
optionally, a carrier or diluent.
11. The formulation of claim 10 wherein the weight ratio of a compound of Formula 1
and the one or more co-agents is from 10: 1 to 1: 1 000.
12. A formulation for treating psoriais comprising:
a compound of Formula I of any of claims 1 to 8, or a pharmaceutically
acceptable salt or ester derivative thereof;
one or more co-agents selected from the group consisting of: topical
glucocorticoids , salicylic acid, crude coal tar; and
.optionally, a carrier or diluent.
13. The formulation of claim 12 wherein the weight ratio of Formula I and the one or
more co-agents is from 1: 1 0 to 1: 100000.
14. A compound or a pharmaceutically acceptable salt, a pharmaceutical formulation
and a formulation for treating osteoporosis substantially as herein described with
reference to foregoing illustrations and examples.

The present invention relates to novel, non-secosteroidal, phenyl-benzoxazole compounds
of Formula (I) wherein the variables R, R', RP, RP3, LP1, LP2, ZP, RB, RB', LXB and
ZXB are as hereinafter defined, their preparation, pharmaceutical compositions, and
methods of use.