U.S. patent application number 11/498124 was filed with the patent office on 2006-11-30 for ep4 receptor agonist, compositions and methods thereof.
Invention is credited to Xavier Billot, John Colucci, Yongxin Han, Marie-Claire Wilson, Robert Young.
Application Number | 20060270721 11/498124 |
Document ID | / |
Family ID | 31978315 |
Filed Date | 2006-11-30 |
United States Patent
Application |
20060270721 |
Kind Code |
A1 |
Han; Yongxin ; et
al. |
November 30, 2006 |
EP4 receptor agonist, compositions and methods thereof
Abstract
This invention relates to potent selective agonists of the
EP.sub.4 subtype of prostaglandin E2 receptors, their use or a
formulation thereof in the treatment of glaucoma and other
conditions which are related to elevated intraocular pressure in
the eye of a patient. This invention further relates to the use of
the compounds of this invention for mediating the bone modeling and
remodeling processes of the osteoblasts and osteoclasts.
Inventors: |
Han; Yongxin; (Kirkland,
CA) ; Colucci; John; (Westmount, CA) ; Billot;
Xavier; (Montreal, CA) ; Wilson; Marie-Claire;
(Montreal, CA) ; Young; Robert; (Senneville,
CA) |
Correspondence
Address: |
MERCK AND CO., INC
P O BOX 2000
RAHWAY
NJ
07065-0907
US
|
Family ID: |
31978315 |
Appl. No.: |
11/498124 |
Filed: |
August 2, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10521508 |
Jan 18, 2005 |
7109223 |
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PCT/CA03/01306 |
Aug 25, 2003 |
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11498124 |
Aug 2, 2006 |
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60406530 |
Aug 28, 2002 |
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Current U.S.
Class: |
514/369 ;
514/376; 548/190; 548/229 |
Current CPC
Class: |
C07D 417/06 20130101;
A61P 27/02 20180101; A61P 43/00 20180101; C07D 263/24 20130101;
A61P 27/06 20180101; C07D 417/10 20130101; C07D 413/10 20130101;
C07D 263/20 20130101; C07D 413/06 20130101; C07D 277/14 20130101;
C07D 413/14 20130101 |
Class at
Publication: |
514/369 ;
514/376; 548/229; 548/190 |
International
Class: |
A61K 31/426 20060101
A61K031/426; A61K 31/421 20060101 A61K031/421 |
Claims
1. A compound having the structural formula I: ##STR21## or a
pharmaceutically acceptable salt thereof, wherein, X is O or S;
Y.sup.1 is 1) CH.sub.2CH.sub.2, 2) CHCH, or 3) ##STR22## Y is C(O)
or CH(OH); A and W are independently selected from the group
consisting of 1) a bond, and 2) C.sub.1-6 alkylene, unsubstituted
or substituted with 1, 2, 3, or 4 halogen atoms; Z is 1) O, 2) S,
3) ##STR23## 7) a disubstituted aryl or heteroaryl ring, wherein
one ring atom of the ring is attached to the moiety ##STR24## and
another ring atom is attached to the moiety ##STR25## with the
proviso that when Z is O or S, then A and W are independently
selected from the group consisting of C.sub.1-6 alkylene,
unsubstituted or substituted with 1, 2, 3, or 4 halogen atoms;
R.sup.1 is COR.sup.5, OH, CN, (CH.sub.2).sub.1-3 CO.sub.2R.sup.6,
(CH.sub.2).sub.0-4SO.sub.3R.sup.6, CF.sub.2SO.sub.2NH.sub.2,
SO.sub.2NH.sub.2, SO.sub.2NHCOR.sup.8, PO(OH).sub.2, C.sub.1-4
alkoxy, hydroxymethylketone, (CH.sub.2).sub.0-4 heterocyclyl,
wherein heterocyclyl is unsubstituted or substituted with 1 to 3
groups of R.sup.a, or tetrazole; R.sup.2 is 1) C.sub.1-6alkyl,
provided that R.sup.2 is not n-pentyl, 2)
(CH.sub.2).sub.0-8C.sub.6-10aryl, 3)
(CH.sub.2).sub.0-8C.sub.5-10heteroaryl, 4)
(CH.sub.2).sub.0-8C.sub.3-10heterocycloalkyl, 5)
(CH.sub.2).sub.0-8C.sub.3-8cycloalkyl, 6) O--C.sub.1-10alkyl, 7)
O--C.sub.6-10aryl, 8) O--C.sub.5-10heteroaryl, 9)
O--C.sub.5-10heterocycloalkyl, 10) O--C.sub.3-10cycloalkyl wherein
aryl, heteroaryl, heterocycloalkyl, and cycloalkyl are
unsubstituted or substituted with 1-3 groups of R.sup.b; R.sup.3
and R.sup.4 are independently selected from the group consisting of
1) hydrogen, 2) halogen, and 3) C.sub.1-6 alkyl, or R.sup.3 and
R.sup.4, together with the carbon atom to which they are attached,
form a C.sub.3-7 cycloalkyl ring; R.sup.5 is 1) hydrogen, 2) OH, 3)
CH.sub.2OH, 4) C.sub.1-6 alkoxy, 5) NHPO.sub.2R.sup.6, 6)
NHR.sup.9, 7) NHSO.sub.2R.sup.8, or 8) NR.sup.6R.sup.7; R.sup.6 and
R.sup.7 are independently selected from the group consisting of
hydrogen and C.sub.1-6 alkyl; R.sup.8 is selected from the group
consisting of hydrogen, C.sub.6-10aryl, and C.sub.1-4alkyl; R.sup.9
is acyl or sulfonyl; and R.sup.a and R.sup.b are independently
selected from the group consisting of 1) C.sub.1-6alkoxy, 2)
C.sub.1-6alkyl, unsubstituted or substituted with a) C.sub.1-6
alkoxy, b) C.sub.1-6 alkylthio, c) CN, d) OH, or e) CF.sub.3, 3)
CF.sub.3, 4) nitro, 5) amino, 6) cyano, 7) C.sub.1-6alkylamino, 8)
halogen 9) OR.sup.c, 10) OCH.sub.2R.sup.c, and 11)
CH.sub.2OR.sup.c; R.sup.c is 1) C.sub.6-10aryl, 2)
C.sub.5-10heteroaryl, 3) C.sub.3-10heterocycloalkyl, or 4)
C.sub.3-8cycloalkyl.
2. A compound of claim 1, or a pharmaceutically acceptable salt
thereof, wherein R.sup.2 is 1) cyclohexyl, 2) unsubstituted aryl,
or 3) aryl substituted with a) unsubstituted C.sub.1-6 alkyl, b)
C.sub.1-6 alkyl substituted with C.sub.1-6 alkoxy c) halogen, or d)
CF.sub.3.
3. A compound of claim 2, or a pharmaceutically acceptable salt
thereof, wherein R.sup.1 is tetrazole or COR.sup.5, wherein R.sup.5
is CH.sub.2OH or OH.
4. A compound of claim 3, or a pharmaceutically acceptable salt
thereof, wherein A is a bond, (CH.sub.2).sub.1-4, or
(CH.sub.2).sub.1-5CF.sub.2, and W is a bond or
(CH.sub.2).sub.1-6.
5. A compound of claim 4, or a pharmaceutically acceptable salt
thereof, wherein Z is 4) O, 5) S, ##STR26## 7) disubstituted
thiophene, 8) disubstituted furan, or 9) disubstituted benzene; and
R.sup.3 and R.sup.4 are independently selected from the group
consisting of hydrogen and F, or R.sup.3 and R.sup.4, together with
the carbon atom to which they are attached, formn a cyclopropyl or
cyclohexyl ring.
6. A compound of claim 5 selected from the group consisting of
4-[2-(2,2-difluoro-1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazo-
l-5-yl)hexyl]-1,3-thiazolidin-2-one,
4-[2-(1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazol-5-yl)hexyl]-
-1,3-thiazolidin-2-one,
4-[2-(1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazol-5-yl)hexyl]-
-1,3-thiazolidin-2-one,
5-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propyl)thiophene-2-carboxylic acid,
5-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propyl)-2-furoic acid,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[5-(1H-tetraazol--
5-yl)-2-furyl]propyl}-1,3-thiazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[5-(1H-tetraazol--
5-yl)thien-2-yl]propyl}-1,3-thiazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2E)-3-[5-(1H-tetra-
azol-5-yl)thien-2-yl]prop-2-enyl}-1,3-thiazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2E)-3-[5-(1H-tetra-
azol-5-yl)-2-furyl]prop-2-enyl}-1,3-thiazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2Z)-3-[5-(1H-tetra-
azol-5-yl)thien-2-yl]prop-2-enyl}-1,3-thiazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2Z)-3-[5-(1H-tetra-
azol-5-yl)-2-furyl]prop-2-enyl}-1,3-thiazolidin-2-one,
3-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propyl)benzoic acid,
4-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propyl)benzoic acid,
2-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propyl)benzoic acid,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[3-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-thiazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[2-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-thiazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[4-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-thiazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[3-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-thiazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[4-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl)}-1,3-thiazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[2-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-thiazolidin-2-one,
4-(2-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}ethoxy)butanoic acid,
3-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propoxy)propanoic acid,
(4-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazoli-
din-3-yl}butoxy)acetic acid,
[(4-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazol-
idin-3-yl}butyl)thio]acetic acid,
3-[(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiaz-
olidin-3-yl}propyl)thio]propanoic acid,
4-[(2-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiaz-
olidin-3-yl}ethyl)thio]butanoic acid,
4-[2-(2,2-difluoro-1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazo-
l-5-yl)hexyl]-1,3-oxazolidin-2-one,
4-[2-(1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazol-5-yl)hexyl]-
-1,3-oxazolidin-2-one,
4-[2-(1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazol-5-yl)hexyl]-
-1,3-oxazolidin-2-one,
5-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propyl)thiophene-2-carboxylic acid,
5-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propyl)-2-furoic acid,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[5-(1H-tetraazol--
5-yl)-2-furyl]propyl}-1,3-oxazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[5-(1H-tetraazol--
5-yl)thien-2-yl]propyl}-1,3-oxazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2E)-3-[5-(1H-tetra-
azol-5-yl)thien-2-yl]prop-2-enyl}-1,3-oxazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2E)-3-[5-(1H-tetra-
azol-5-yl)-2-furyl]prop-2-enyl}-1,3-oxazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2Z)-3-[5-(1H-tetra-
azol-5-yl)thien-2-yl]prop-2-enyl}-1,3-oxazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2Z)-3-[5-(1H-tetra-
azol-5-yl)-2-furyl]prop-2-enyl}-1,3-oxazolidin-2-one,
3-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propyl)benzoic acid,
4-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propyl)benzoic acid,
2-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propyl)benzoic acid,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[3-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-oxazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[2-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-oxazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[4-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-oxazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[3-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-oxazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[4-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-oxazolidin-2-one,
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[2-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-oxazolidin-2-one,
4-(2-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}ethoxy)butanoic acid,
3-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propoxy)propanoic acid,
(4-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolid-
in-3-yl}butoxy)acetic acid,
[(4-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazoli-
din-3-yl}butyl)thio]acetic acid,
3-[(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazo-
lidin-3-yl}propyl)thio]propanoic acid,
4-[(2-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazo-
lidin-3-yl}ethyl)thio]butanoic acid, or a pharmaceutically
acceptable salt thereof.
7. A method for treating disorders related to elevated intraocular
pressure by: treating ocular hypertension, treating glaucoma,
treating macular edema, treating macular degeneration, increasing
retinal and optic nerve head blood velocity, increasing retinal and
optic nerve tension, providing a neuroprotective effect or treating
dry eyes, comprising administering to a patient in need of such
treatment a therapeutically effective amount of a compound of
therapeutically effective amount of a compound of claim 1.
8. A method according to claim 7 wherein the topical formulation
optionally contains xanthan gum or gellan gum.
9. A method according to claim 8 wherein the topical formulation is
a solution or suspension.
10. A method according to claim 7 further comprising administering
to the patient an active ingredient selected from the group
consisting of a .beta.-adrenergic blocking agent, a
parasympatho-mimetic agent, a sympathomimetic agent, a carbonic
anhydrase inhibitor, a prostaglandin, a hypotensive lipid, a
neuroprotectant, and a 5-HT2 receptor agonist, is added to the
formulation.
11. A method according to claim 10 wherein the .beta.-adrenergic
blocking agent is timolol, betaxolol, levobetaxolol, carteolol, or
levobunolol; the parasympathomimetic agent is pilocarpine; the
sympathomimetic agent is epinephrine, brimonidine, iopidine,
clonidine, or para-aminoclonidine; the carbonic anhydrase inhibitor
is dorzolamide, acetazolamide, metazolamide or brinzolamide; the
prostaglandin is latanoprost, travaprost, unoprostone, rescula, or
S1033; the hypotensive lipid is lumigan; the neuroprotectant is
eliprodil, R-eliprodil or memantine; and the 5-HT2 receptor agonist
is 1-(2-aminopropyl)-3-methyl-1H-imdazol-6-ol fumarate or
2-(3-chloro-6-methoxy-indazol-1-yl)-1-methyl-ethylamine.
12. A pharmaceutical composition which is comprised of a compound
in accordance with claim 1 and a pharmaceutically acceptable
carrier.
Description
[0001] This Application claims the benefit of U.S. Provisional
Application 60/406,530, filed Aug. 28, 2002.
BACKGROUND OF THE INVENTION
[0002] Glaucoma is a degenerative disease of the eye wherein the
intraocular pressure is too high to permit normal eye function. As
a result, damage may occur to the optic nerve head and result in
irreversible loss of visual function. If untreated, glaucoma may
eventually lead to blindness. Ocular hypertension, i.e., the
condition of elevated intraocular pressure without optic nerve head
damage or characteristic glaucomatous visual field defects, is now
believed by the majority of ophthalmologists to represent merely
the earliest phase in the onset of glaucoma.
[0003] Many of the drugs formerly used to treat glaucoma proved
unsatisfactory. Early methods of treating glaucoma employed
pilocarpine and produced undesirable local effects that made this
drug, though valuable, unsatisfactory as a first line drug. More
recently, clinicians have noted that many .beta.-adrenergic
antagonists are effective in reducing intraocular pressure. While
many of these agents are effective for this purpose, there exist
some patients with whom this treatment is not effective or not
sufficiently effective. Many of these agents also have other
characteristics, e.g., membrane stabilizing activity, that become
more apparent with increased doses and render them unacceptable for
chronic ocular use and can also cause cardiovascular effects.
[0004] Agents referred to as carbonic anhydrase inhibitors decrease
the formation of aqueous humor by inhibiting the enzyme carbonic
anhydrase. While such carbonic anhydrase inhibitors are now used to
treat elevated intraocular pressure by systemic and topical routes,
current therapies using these agents, particularly those using
systemic routes are still not without undesirable effects.
Topically effective carbonic anhydrase inhibitors are disclosed in
U.S. Pat. Nos. 4,386,098; 4,416,890; 4,426,388; 4,668,697;
4,863,922; 4,797,413; 5,378,703, 5,240,923 and 5,153,192.
[0005] Prostaglandins and prostaglandin derivatives are also known
to lower intraocular pressure. There are several prostaglandin
types, including the A, B, C, D, E, F, G, I and J-Series (EP
0561073 A1). U.S. Pat. No. 4,883,819 to Bito describes the use and
synthesis of PGAs, PGBs and PGCs in reducing intraocular pressure.
U.S. Pat. No. 4,824,857 to Goh et al. describes the use and
synthesis of PGD.sub.2 and derivatives thereof in lowering
intraocular pressure including derivatives wherein C-10 is replaced
with nitrogen. U.S. Pat. No. 5,001,153 to Ueno et al. describes the
use and synthesis of 13,14-dihydro-15-keto prostaglandins and
prostaglandin derivatives to lower intraocular pressure. U.S. Pat.
No. 4,599,353 describes the use of eicosanoids and eicosanoid
derivatives including prostaglandins and prostaglandin inhibitors
in lowering intraocular pressure. See also WO 00/38667, WO
99/32441, WO 99/02165, WO 00/38663, WO 01/46140, EP 0855389, JP
2000-1472, U.S. Pat. No. 6,043,275 and WO 00/38690.
[0006] Prostaglandin and prostaglandin derivatives are known to
lower intraocular pressure by increasing uveoscleral outflow. This
is true for both the F type and A type of prostaglandins. This
invention is particularly interested in those compounds that lower
IOP via the uveoscleral outflow pathway and other mechanisms by
which the E series prostaglandins (PGE.sub.2) may facilitate IOP
reduction. The four recognized subtypes of the EP receptor are
believed to modulate the effect of lowering IOP (EP.sub.1,
EP.sub.2, EP.sub.3 and EP.sub.4; J. Lipid Mediators Cell Signaling,
Vol. 14, pages 83-87 (1996)). See also J. Ocular Pharmacology, Vol.
4, 1, pages 13-18 (1988); J. Ocular Pharmacology and Therapeutics,
Vol. 11, 3, pages 447-454 (1995); J. Lipid Mediators, Vol. 6, pages
545-553 (1993); U.S. Pat. Nos. 5,698,598 and 5,462,968 and
Investigative Ophthalmology and Visual Science, Vol. 31, 12, pages
2560-2567 (1990). Of particular interest to this invention are
compounds, which are agonist of the EP.sub.4 subtype receptor.
[0007] A problem with using prostaglandins or derivatives thereof
to lower intraocular pressure is that these compounds often induce
an initial increase in intraocular pressure, can change the color
of eye pigmentation and cause proliferation of some tissues
surrounding the eye.
[0008] As can be seen, there are several current therapies for
treating glaucoma and elevated intraocular pressure, but the
efficacy and the side effect profiles of these agents are not
ideal. Therefore, there still exist the need for new and effective
therapies with little or no side effects.
[0009] A variety of disorders in humans and other mammals involve
or are associated with abnormal or excessive bone loss. Such
disorders include, but are not limited to, osteoporosis,
glucocorticoid induced osteoporosis, Paget's disease, abnormally
increased bone turnover, periodontal disease, tooth loss, bone
fractures, rheumatoid arthritis, periprosthetic osteolysis,
osteogenesis imperfecta, metastatic bone disease, hypercalcemia of
malignancy, and multiple myeloma. One of the most common of these
disorders is osteoporosis, which in its most frequent manifestation
occurs in postmenopausal women. Osteoporosis is a systemic skeletal
disease characterized by a low bone mass and microarchitectural
deterioration of bone tissue, with a consequent increase in bone
fragility and susceptibility to fracture. Osteoporotic fractures
are a major cause of morbidity and mortality in the elderly
population. As many as 50% of women and a third of men will
experience an osteoporotic fracture. A large segment of the older
population already has low bone density and a high risk of
fractures. There is a significant need to both prevent and treat
osteoporosis and other conditions associated with bone resorption.
Because osteoporosis, as well as other disorders associated with
bone loss, are generally chronic conditions, it is believed that
appropriate therapy will typically require chronic treatment.
[0010] Two different types of cells called osteoblasts and
osteoclasts are involved in the bone formation and resorption
processes, respectively. See H. Fleisch, Bisphosphonates In Bone
Disease, From The Laboratory To The Patient, 3rd Edition, Parthenon
Publishing (1997), which is incorporated by reference herein in its
entirety. Osteoblasts are cells that are located on the bone
surface. These cells secrete an osseous organic matrix, which then
calcifies. Substances such as fluoride, parathyroid hormone, and
certain cytokines such as protaglandins are known to provide a
stimulatory effect on osetoblast cells. However, an aim of current
research is to develop therapeutic agents that will selectively
increase or stimulate the bone formation activity of the
osteoblasts.
[0011] Osteoclasts are usually large multinucleated cells that are
situated either on the surface of the cortical or trabecular bone
or within the cortical bone. The osteoclasts resorb bone in a
closed, sealed-off microenvironment located between the cell and
the bone. The recruitment and activity of osteoclasts is known to
be influenced by a series of cytokines and hormones. It is well
known that bisphosphonates are selective inhibitors of osteoclastic
bone resorption, making these compounds important therapeutic
agents in the treatment or prevention of a variety of systemic or
localized bone disorders caused by or associated with abnormal bone
resorption. However, despite the utility of bisphosphonates there
remains the desire amongst researchers to develop additional
therapeutic agents for inhibiting the bone resorption activity of
osteoclasts.
[0012] Prostaglandins such as the PGE.sub.2 series are known to
stimulate bone formation and increase bone mass in mammals,
including man. It is believed that the four different receptor
subtypes, designated EP.sub.1, EP.sub.2, EP.sub.3, and EP.sub.4 are
involved in mediating the bone modeling and remodeling processes of
the osteoblasts and osteoclasts. The major prostaglandin receptor
in bone is EP.sub.4, which is believed to provide its effect by
signaling via cyclic AMP.
[0013] In present invention it is further found that the formula I
agonists of the EP.sub.4 subtype receptor are useful for
stimulating bone formation.
[0014] WO 02/24647, WO 02/42268, EP 1132086, EP 855389, EP 1114816,
WO 01/46140 and WO 01/72268 disclose EP.sub.4 agonists.
SUMMARY OF THE INVENTION
[0015] This invention relates to potent selective agonists of the
EP.sub.4 subtype of prostaglandin E2 receptors, their use or a
formulation thereof in the treatment of glaucoma and other
conditions that are related to elevated intraocular pressure in the
eye of a patient. Another aspect of this invention relates to the
use of such compounds to provide a neuroprotective effect to the
eye of mammalian species, particularly humans. This invention
further relates to the use of the compounds of this invention for
mediating the bone modeling and remodeling processes of the
osteoblasts and osteoclasts.
[0016] More particularly, this invention relates to novel EP4
agonist having the structural formula I: ##STR1## or a
pharmaceutically acceptable salt thereof, wherein, [0017] X is O or
S; [0018] Y.sup.1 is [0019] 1) CH.sub.2CH.sub.2, [0020] 2) CHCH, or
##STR2## [0021] Y is C(O) or CH(OH); [0022] A and W are
independently selected from the group consisting of [0023] 1) a
bond, and [0024] 2) C.sub.1-6 alkylene, unsubstituted or
substituted with 1, 2, 3, or 4 halogen atoms; [0025] Z is [0026] 1)
O, [0027] 2) S, ##STR3## [0028] 4) CH.sub.2 [0029] 5) HC.dbd.CH,
[0030] 6) C.ident.C, or [0031] 7) a disubstituted aryl or
heteroaryl ring, wherein one ring atom of the ring is attached to
the moiety ##STR4## [0032] and another ring atom is attached to the
moiety ##STR5## with the proviso that when Z is O or S, then A and
W are independently selected from the group consisting of C.sub.1-6
alkylene, unsubstituted or substituted with 1, 2, 3, or 4 halogen
atoms; [0033] R.sup.1 is [0034] COR.sup.5, [0035] OH, [0036] CN,
[0037] (CH.sub.2).sub.1-3 CO.sub.2R.sup.6, [0038]
(CH.sub.2).sub.0-4SO.sub.3R.sup.6, [0039] CF.sub.2SO.sub.2NH.sub.2,
[0040] SO.sub.2NH.sub.2, [0041] SO.sub.2NHCOR.sup.8, [0042]
PO(OH).sub.2, [0043] C.sub.1-4 alkoxy, [0044] hydroxymethylketone,
[0045] (CH.sub.2).sub.0-4 heterocyclyl, wherein heterocyclyl is
unsubstituted or substituted with 1 to 3 groups of R.sup.a, or
tetrazole; [0046] R.sup.2 is [0047] 1) C.sub.1-6alkyl, provided
that R.sup.2 is not n-pentyl, [0048] 2)
(CH.sub.2).sub.0-8C.sub.6-10aryl, [0049] 3)
(CH.sub.2).sub.0-8C.sub.5-10heteroaryl, [0050] 4)
(CH.sub.2).sub.0-8C.sub.3-10heterocycloalkyl, [0051] 5)
(CH.sub.2).sub.0-8C.sub.3-8cycloalkyl, [0052] 6)
O--C.sub.1-10alkyl, [0053] 7) O--C.sub.6-10aryl, [0054] 8)
O--C.sub.5-10heteroaryl, [0055] 9) O--C.sub.5-10heterocycloalkyl,
[0056] 10) O--C.sub.3-10cycloalkyl wherein aryl, heteroaryl,
heterocycloalkyl, and cycloalkyl are unsubstituted or substituted
with 1-3 groups of R.sup.b; [0057] R.sup.3 and R.sup.4 are
independently selected from the group consisting of [0058] 1)
hydrogen, [0059] 2) halogen, and [0060] 3) C.sub.1-6 alkyl, or
[0061] R.sup.3 and R.sup.4, together with the carbon atom to which
they are attached, form a C.sub.3-7 cycloalkyl ring; [0062] R.sup.5
is [0063] 1) hydrogen, [0064] 2) OH, [0065] 3) CH.sub.2OH, [0066]
4) C.sub.1-6 alkoxy, [0067] 5) NHPO.sub.2R.sup.6, [0068] 6)
NHR.sup.9, [0069] 7) NHSO.sub.2R.sup.8, or [0070] 8)
NR.sup.6R.sup.7; [0071] R.sup.6 and R.sup.7 are independently
selected from the group consisting of hydrogen and C.sub.1-6 alkyl;
[0072] R.sup.8 is selected from the group consisting of hydrogen,
C.sub.6-10aryl, and C.sub.1-4alkyl; [0073] R.sup.9 is acyl or
sulfonyl; and [0074] R.sup.a and R.sup.b are independently selected
from the group consisting of [0075] 1) C.sub.1-6alkoxy, [0076] 2)
C.sub.1-6alkyl, unsubstituted or substituted with [0077] a)
C.sub.1-6 alkoxy, [0078] b) C.sub.1-6 alkylthio, [0079] c) CN,
[0080] d) OH, or [0081] e) CF.sub.3, [0082] 3) CF.sub.3, [0083] 4)
nitro, [0084] 5) amino, [0085] 6) cyano, [0086] 7)
C.sub.1-6alkylamino, [0087] 8) halogen [0088] 9) OR.sup.c, [0089]
10) OCH.sub.2R.sup.c, and [0090] 11) CH.sub.2OR.sup.c; [0091]
R.sup.c is [0092] 1) C.sub.6-10aryl, [0093] 2)
C.sub.5-10heteroaryl, [0094] 3) C.sub.3-10heterocycloalkyl, or
[0095] 4) C.sub.3-8cycloalkyl.
[0096] The compounds of the present invention may have chiral
centers and occur as racemates, racemic mixtures and as individual
diastereomers, or enantiomers with all isomeric forms being
included in the present invention. The compounds of the present
invention may also have polymorphic crystalline forms, with all
polymorphic crystalline forms being included in the present
invention. The compounds of the invention also include tautomeric
forms, with all tautomeric forms being included in the present
invention.
[0097] The invention also includes prodrug forms of the
above-described compounds. Prodrugs, such as ester derivatives of
active drug, are compound derivatives which, when absorbed into the
bloodstream of a warm-blooded animal, cleave in such a manner as to
release the drug form and permit the drug to afford improved
therapeutic efficacy. The prodrugs may be administered in low
amounts relative to the amounts of antagonist that would ordinarily
be administered. The prodrugs may be administered orally. The
prodrugs retain structural integrity while passing though the
gastrointestinal system, and are effectively delivered to cells.
They are subjected to metabolic reactions to form the active acid
which then interacts with the platelet receptor site.
[0098] This and other aspects of the invention will be realized
upon inspection of the invention as a whole.
DETAILED DESCRIPTION OF THE INVENTION
[0099] In a class of compounds and pharmaceutically acceptable
salts of the invention, [0100] R.sup.2 is [0101] 1) cyclohexyl,
[0102] 2) unsubstituted aryl, or [0103] 3) aryl substituted with
[0104] a) unsubstituted C.sub.1-6 alkyl, [0105] b) C.sub.1-6 alkyl
substituted with C.sub.1-6 alkoxy [0106] c) halogen, or [0107] d)
CF.sub.3.
[0108] In a subclass of this class, R.sup.1 is tetrazole or
COR.sup.5, wherein R.sup.5 is CH.sub.2OH or OH.
[0109] In a group of this subclass, A is a bond,
(CH.sub.2).sub.1-4, or (CH.sub.2).sub.1-5CF.sub.2, and W is a bond
or (CH.sub.2).sub.1-6.
[0110] In a subgroup of this group, [0111] Z is [0112] 1) CH.sub.2,
[0113] 2) CH.dbd.CH, [0114] 3) C.ident.C, [0115] 4) O, [0116] 5) S,
[0117] 6) ##STR6## [0118] 7) disubstituted thiophene, [0119] 8)
disubstituted furan, or [0120] 9) disubstituted benzene; and [0121]
R.sup.3 and R.sup.4 are independently selected from the group
consisting of hydrogen and F, or R.sup.3 and R.sup.4, together with
the carbon atom to which they are attached, form a cyclopropyl or
cyclohexyl ring.
[0122] Exemplary compounds of this invention include [0123]
7-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazolid-
in-3-yl}heptanoic acid, [0124]
7-{4-[(1E)-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazolidin-3-yl}hepta-
noic acid, [0125]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-y-
l)hexyl]-1,3-thiazolidin-2-one, [0126]
4-[(1E)-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-yl)hexyl]-1,3--
thiazolidin-2-one, [0127]
4-[(1E)-3-hydroxy-3-(1-phenylcyclopropyl)prop-1-enyl]-3-[6-(1H-tetraazol--
5-yl)hexyl]-1,3-thiazolidin-2-one, [0128]
4-(3-hydroxy-4-phenylbutyl)-3-[6-(1H-tetraazol-5-yl)hexyl]-1,3-thiazolidi-
n-2-one, [0129]
4-(4,4-difluoro-3-hydroxy-4-phenylbutyl)-3-[6-(1H-tetraazol-5-yl)hexyl]-1-
,3-thiazolidin-2-one, [0130]
7-(4-{(1E)-4,4-difluoro-3-hydroxy-4-[3-(methoxymethyl)phenyl]but-1-enyl
}-2-oxo-1,3-thiazolidin-3-yl)heptanoic acid, [0131]
4-{(1E)-4,4-difluoro-3-hydroxy-4-[3-(methoxymethyl)phenyl]but-1-enyl}-3-[-
6-(1H-tetraazol-5-yl)hexyl]-1,3-thiazolidin-2-one, [0132]
4-[(1E)-4-cyclohexyl-4,4-difluoro-3-hydroxybut-1-enyl]-3-[6-(1H-tetraazol-
-5-yl)hexyl]-1,3-thiazolidin-2-one, [0133]
4-[(1E)-4-cyclohexyl-3-hydroxybut-1-enyl]-3-[6-(1H-tetraazol-5-yl)hexyl]--
1,3-thiazolidin-2-one, [0134]
4-(4,4-difluoro-3-oxo-4-phenylbutyl)-3-[6-(1H-tetraazol-5-yl)hexyl]-1,3-t-
hiazolidin-2-one, [0135]
4-(3-oxo-4-phenylbutyl)-3-[6-(1H-tetraazol-5-yl)hexyl]-1,3-thiazolidin-2--
one, [0136]
4-[2-(2,2-difluoro-1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazo-
l-5-yl)hexyl]-1,3-thiazolidin-2-one, [0137]
4-[2-(1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazol-5-yl)hexyl]-
-1,3-thiazolidin-2-one, [0138]
4-[2-(1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazol-5-yl)hexyl]-
-1,3-thiazolidin-2-one, [0139]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-(7-hydroxy-6-oxohept-
yl)-1,3-thiazolidin-2-one, [0140]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(2E)-6-(1H-tetraazo-
l-5-yl)hex-2-enyl]-1,3-thiazolidin-2-one, [0141]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(3E)-6-(1H-tetraazo-
l-5-yl)hex-3-enyl]-1,3-thiazolidin-2-one, [0142]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(4E)-6-(1H-tetraazo-
l-5-yl)hex-4-enyl]-1,3-thiazolidin-2-one, [0143]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(2Z)-6-(1H-tetraazo-
l-5-yl)hex-2-enyl]-1,3-thiazolidin-2-one, [0144]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(3Z)-6-(1H-tetraazo-
l-5-yl)hex-3-enyl]-1,3-thiazolidin-2-one, [0145]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(4Z)-6-(1H-tetraazo-
l-5-yl)hex-4-enyl]-1,3-thiazolidin-2-one, [0146]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-y-
l)hex-4-ynyl]-1,3-thiazolidin-2-one, [0147]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-y-
l)hex-2-ynyl]-1,3-thiazolidin-2-one, [0148]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-y-
l)hex-3-ynyl]-1,3-thiazolidin-2-one, [0149]
5-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propyl)thiophene-2-carboxylic acid, [0150]
5-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propyl)-2-furoic acid, [0151]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[5-(1H-tetraazol--
5-yl)-2-furyl]propyl}-1,3-thiazolidin-2-one, [0152]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[5-(1H-tetraazol--
5-yl)thien-2-yl]propyl}-1,3-thiazolidin-2-one, [0153]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2E)-3-[5-(1H-tetra-
azol-5-yl)thien-2-yl]prop-2-enyl}-1,3-thiazolidin-2-one, [0154]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2E)-3-[5-(1H-tetra-
azol-5-yl)-2-furyl]prop-2-enyl}-1,3-thiazolidin-2-one, [0155]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2Z)-3-[5-(1H-tetra-
azol-5-yl)thien-2-yl]prop-2-enyl}-1,3-thiazolidin-2-one, [0156]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2Z)-3-[5-(1H-tetra-
azol-5-yl)-2-furyl]prop-2-enyl}-1,3-thiazolidin-2-one, [0157]
3-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propyl)benzoic acid, [0158]
4-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propyl)benzoic acid, [0159]
2-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propyl)benzoic acid, [0160]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[3-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-thiazolidin-2-one, [0161]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[2-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-thiazolidin-2-one, [0162]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[4-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-thiazolidin-2-one, [0163]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[3-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-thiazolidin-2-one, [0164]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[4-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-thiazolidin-2-one, [0165]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[2-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-thiazolidin-2-one, [0166]
7-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazolid-
in-3-yl}-2,2-difluoroheptanoic acid, [0167]
7-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazolid-
in-3-yl}-4,4-difluoroheptanoic acid, [0168]
7-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazolid-
in-3-yl}-5,5-difluoroheptanoic acid, [0169]
7-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazolid-
in-3-yl}-6,6-difluoroheptanoic acid, [0170]
4-(2-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}ethoxy)butanoic acid, [0171]
3-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazo-
lidin-3-yl}propoxy)propanoic acid, [0172]
(4-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazoli-
din-3-yl}butoxy)acetic acid, [0173]
[(4-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazol-
idin-3-yl}butyl)thio]acetic acid, [0174]
3-[(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiaz-
olidin-3-yl}propyl)thio]propanoic acid, [0175]
4-[(2-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiaz-
olidin-3-yl}ethyl)thio]butanoic acid, [0176]
7-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidi-
n-3-yl}heptanoic acid, [0177]
7-{4-[(1E)-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidin-3-yl}heptan-
oic acid, [0178]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-y-
l)hexyl]-1,3-oxazolidin-2-one, [0179]
4-[(1E)-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-yl)hexyl]-1,3--
oxazolidin-2-one, [0180]
4-[(1E)-3-hydroxy-3-(1-phenylcyclopropyl)prop-1-enyl]-3-[6-(1H-tetraazol--
5-yl)hexyl]-1,3-oxazolidin-2-one,
4-(3-hydroxy-4-phenylbutyl)-3-[6-(1H-tetraazol-5-yl)hexyl]-1,3-oxazolidin-
-2-one, [0181]
4-(4,4-difluoro-3-hydroxy-4-phenylbutyl)-3-[6-(1H-tetraazol-5-yl)hexyl]-1-
,3-oxazolidin-2-one, [0182]
7-(4-{(1E)-4,4-difluoro-3-hydroxy-4-[3-(methoxymethyl)phenyl]but-1-enyl}--
2-oxo-1,3-oxazolidin-3-yl)heptanoic acid, [0183]
4-{(1E)-4,4-difluoro-3-hydroxy-4-[3-(methoxymethyl)phenyl]but-1-enyl}-3-[-
6-(1H-tetraazol-5-yl)hexyl]-1,3-oxazolidin-2-one, [0184]
4-[(1E)-4-cyclohexyl-4,4-difluoro-3-hydroxybut-1-enyl]-3-[6-(1H-tetraazol-
-5-yl)hexyl]-1,3-oxazolidin-2-one, [0185]
4-[(1E)-4-cyclohexyl-3-hydroxybut-1-enyl]-3-[6-(1H-tetraazol-5-yl)hexyl]--
1,3-oxazolidin-2-one, [0186]
4-(4,4-difluoro-3-oxo-4-phenylbutyl)-3-[6-(1H-tetraazol-5-yl)hexyl]-1,3-o-
xazolidin-2-one, [0187]
4-(3-oxo-4-phenylbutyl)-3-[6-(1H-tetraazol-5-yl)hexyl]-1,3-oxazolidin-2-o-
ne, [0188]
4-[2-(2,2-difluoro-1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazo-
l-5-yl)hexyl]-1,3-oxazolidin-2-one, [0189]
4-[2-(1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazol-5-yl)hexyl]-
-1,3-oxazolidin-2-one, [0190]
4-[2-(1-hydroxy-2-phenylethyl)cyclopropyl]-3-[6-(1H-tetraazol-5-yl)hexyl]-
-1,3-oxazolidin-2-one, [0191]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-(7-hydroxy-6-oxohept-
yl)-1,3-oxazolidin-2-one, [0192]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(2E)-6-(1H-tetraazo-
l-5-yl)hex-2-enyl]-1,3-oxazolidin-2-one, [0193]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(3E)-6-(1H-tetraazo-
l-5-yl)hex-3-enyl]-1,3-oxazolidin-2-one, [0194]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(4E)-6-(1H-tetraazo-
l-5-yl)hex-4-enyl]-1,3-oxazolidin-2-one, [0195]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(2Z)-6-(1H-tetraazo-
l-5-yl)hex-2-enyl]-1,3-oxazolidin-2-one, [0196]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(3Z)-6-(1H-tetraazo-
l-5-yl)hex-3-enyl]-1,3-oxazolidin-2-one, [0197]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[(4Z)-6-(1H-tetraazo-
l-5-yl)hex-4-enyl]-1,3-oxazolidin-2-one, [0198]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-y-
l)hex-4-ynyl]-1,3-oxazolidin-2-one, [0199]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-y-
l)hex-2-ynyl]-1,3-oxazolidin-2-one, [0200]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-y-
l)hex-3-ynyl]-1,3-oxazolidin-2-one, [0201]
5-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propyl)thiophene-2-carboxylic acid, [0202]
5-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propyl)-2-fuiroic acid, [0203]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[5-(1H-tetraazol--
5-yl)-2-fuiryl]propyl}-1,3-oxazolidin-2-one, [0204]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[5-(1H-tetraazol--
5-yl)thien-2-yl]propyl}-1,3-oxazolidin-2-one, [0205]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2E)-3-[5-(1H-tetra-
azol-5-yl)thien-2-yl]prop-2-enyl}-1,3-oxazolidin-2-one, [0206]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2E)-3-[5-(1H-tetra-
azol-5-yl)-2-furyl]prop-2-enyl)}-1,3-oxazolidin-2-one, [0207]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2Z)-3-[5-(1H-tetra-
azol-5-yl)thien-2-yl]prop-2-enyl}-1,3-oxazolidin-2-one, [0208]
4-[(E1)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{(2Z)-3-[5-(1H-tetra-
azol-5-yl)-2-furyl]prop-2-enyl}-1,3-oxazolidin-2-one, [0209]
3-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propyl)benzoic acid, [0210]
4-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propyl)benzoic acid, [0211]
2-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propyl)benzoic acid, [0212]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[3-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-oxazolidin-2-one, [0213]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[2-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-oxazolidin-2-one, [0214]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{3-[4-(1H-tetraazol--
5-yl)phenyl]propyl}-1,3-oxazolidin-2-one, [0215]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[3-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-oxazolidin-2-one, [0216]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[4-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-oxazolidin-2-one, [0217]
4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-{2-[2-(1H-tetraazol--
5-ylmethyl)phenyl]ethyl}-1,3-oxazolidin-2-one, [0218]
7-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidi-
n-3-yl}-2,2-difluoroheptanoic acid, [0219]
7-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidi-
n-3-yl}-4,4-difluoroheptanoic acid, [0220]
7-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidi-
n-3-yl}-5,5-difluoroheptanoic acid, [0221]
7-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidi-
n-3-yl}-6,6-difluoroheptanoic acid, [0222]
4-(2-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}ethoxy)butanoic acid, [0223]
3-(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazol-
idin-3-yl}propoxy)propanoic acid, [0224]
(4-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolid-
in-3-yl}butoxy)acetic acid, [0225]
[(4-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazoli-
din-3-yl}butyl)thio]acetic acid, [0226]
3-[(3-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazo-
lidin-3-yl}propyl)thio]propanoic acid, [0227]
4-[(2-{4-[(1E)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazo-
lidin-3-yl}ethyl)thio]butanoic acid, and pharmaceutically
acceptable salts thereof.
[0228] The invention is described herein in detail using the terms
defined below unless otherwise specified.
[0229] The term "therapeutically effective amount", as used herein,
means that amount of the EP.sub.4 receptor subtype agonist of
formula I, or other actives of the present invention, that will
elicit the desired therapeutic effect or response or provide the
desired benefit when administered in accordance with the desired
treatment regimen. A preferred therapeutically effective amount
relating to the treatment of abnormal bone resorption is a bone
formation, stimulating amount. Likewise, a preferred
therapeutically effective amount relating to the treatment of
ocular hypertension or glaucoma is an amount effective for reducing
intraocular pressure and/or treating ocular hypertension and/or
glaucoma.
[0230] The term "pharmaceutically acceptable" as used herein, means
generally suitable for administration to a mammal, including
humans, from a toxicity or safety standpoint.
[0231] The term "prodrug" refers to compounds which are drug
precursors which, following administration and absorption, release
the claimed drug in vivo via some metabolic process. A non-limiting
example of a prodrug of the compounds of this invention would be an
acid of the pyrrolidinone group, where the acid functionality has a
structure that makes it easily hydrolyzed after administration to a
patient. Exemplary prodrugs include acetic acid derivatives that
are non-narcotic, analgesics/non-steroidal, anti-inflammatory drugs
having a free CH.sub.2COOH group (which can optionally be in the
form of a pharmaceutically acceptable salt, e.g.
--CH.sub.2COO--Na+), typically attached to a ring system,
preferably to an aromatic or heteroaromatic ring system.
[0232] The term "alkyl", unless otherwise specified, refers to a
monovalent alkane (hydrocarbon) derived radical containing from 1
to 10 carbon atoms unless otherwise defined. It may be straight,
branched or cyclic. Preferred alkyl groups include methyl, ethyl,
propyl, isopropyl, butyl, t-butyl, cyclopentyl and cyclohexyl. When
the alkyl group is said to be substituted with an alkyl group, this
is used interchangeably with "branched alkyl group".
[0233] The term "alkoxy" refers to C.sub.1-C.sub.6 alkyl-O--, with
the alkyl group optionally substituted as described herein.
Examples of alkoxy groups are methoxy, ethoxy, propoxy, butoxy and
isomeric groups thereof.
[0234] The terms "halogen" or "halo" refer to chlorine, fluorine,
iodine or bromine.
[0235] The term "aryl" refers to aromatic rings e.g., phenyl,
substituted phenyl and the like, as well as rings which are fused,
e.g., naphthyl, phenanthrenyl and the like. An aryl group thus
contains at least one ring having at least 6 atoms, with up to five
such rings being present, containing up to 22 atoms therein, with
alternating (resonating) double bonds between adjacent carbon atoms
or suitable heteroatoms. The preferred aryl groups are phenyl,
naphthyl and phenanthrenyl. Unless otherwise specified, the aryl
ring can be unsubstituted or substituted with one or more of
--CF.sub.3, --CN, C.sub.1-4 alkyl, hydroxy, C.sub.1-4 alkoxy,
halogen, e.g. F, Cl, Br, or I, --NO.sub.2, --NR.sup.dR.sup.f,
--SO.sub.2R.sup.d, SO.sub.2NR.sup.dR.sup.f, --CONR.sup.dR.sup.f, or
COR.sup.d, wherein R.sup.d and R.sup.f are independently selected
hydrogen and C.sub.1-4 alkyl. Preferred substituted aryls include
phenyl and naphthyl.
[0236] The term "heterocycloalkyl" refers to a cycloalkyl group
(nonaromatic) having 3 to 10 carbon atoms in which one of the
carbon atoms in the ring is replaced by a heteroatom selected from
O, S or N, and in which up to three additional carbon atoms may be
replaced by hetero atoms. Unless otherwise specified, the
heterocycloalkyl ring can be unsubstituted or substituted with one
or more of C.sub.1-4 alkyl, hydroxy, C.sub.1-4 alkoxy, amino, and
halogen, e.g. F, Cl, Br, or I.
[0237] The term "cycloalkyl", unless otherwise specified, refers to
a cyclic alkyl group (nonaromatic) having the specified number of
carbon atoms, e.g., C.sub.3-7 cycloalkyl has 3, 4, 5, 6, or 7
carbon atoms. Unless otherwise specified, the cycloalkyl ring can
be unsubstituted or substituted with one or more of C.sub.1-4
alkyl, hydroxy, C.sub.1-4 alkoxy, amino, and halogen, e.g. F, Cl,
Br, or I. Examples include cyclopropyl, cyclobutyl, and
cyclopentyl.
[0238] The term "heteroatom" means O, S or N, selected on an
independent basis.
[0239] The term "heteroaryl" refers to a monocyclic aromatic
hydrocarbon group having 5 or 6 ring atoms, or a bicyclic aromatic
group having 8 to 10 atoms, containing at least one heteroatom, O,
S or N, in which a carbon or nitrogen atom is the point of
attachment, and in which one or two additional carbon atoms is
optionally replaced by a heteroatom selected from O or S, and in
which from 1 to 3 additional carbon atoms are optionally replaced
by nitrogen heteroatoms, said heteroaryl group being optionally
substituted as described herein. Examples of this type are pyrrole,
pyridine, oxazole, thiazole, tetrazole, and oxazine. Unless
otherwise specified, the heteraryl ring can be unsubstituted or
substituted with one or more of C.sub.1-4 alkyl, hydroxy, C.sub.1-4
alkoxy, amino, and halogen, e.g. F, Cl, Br, or I. For purposes of
this invention the tetrazole includes all tautomeric forms.
Additional nitrogen atoms may be present together with the first
nitrogen and oxygen or sulfur, giving, e.g., thiadiazole.
[0240] The terms "heterocyclyl" and "heterocyclic", as used herein,
represent a stable 5- to 7-membered monocyclic or stable 8- to
11-membered bicyclic heterocyclic ring which is either saturated or
unsaturated, and which consists of carbon atoms and from one to
four heteroatoms selected from the group consisting of N, O, and S,
and including any bicyclic group in which any of the above-defined
heterocyclic rings is fused to a benzene ring. The heterocyclic
ring may be attached at any heteroatom or carbon atom which results
in the creation of a stable structure. A fused heterocyclic ring
system may include carbocyclic rings and need include only one
heterocyclic ring. The term heterocycle or heterocyclic includes
heteroaryl moieties. Examples of such heterocyclic elements
include, but are not limited to, azepinyl, benzimidazolyl,
benzisoxazolyl, benzofurazanyl, benzopyranyl, benzothiopyranyl,
benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, chromanyl,
cinnolinyl, dihydrobenzofuryl, dihydrobenzothienyl,
dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone,
1,3-dioxolanyl, furyl, imidazolidinyl, imidazolinyl, imidazolyl,
indolinyl, indolyl, isochromanyl, isoindolinyl, isoquinolinyl,
isothiazolidinyl, isothiazolyl, isothiazolidinyl, morpholinyl,
naphthyridinyl, oxadiazolyl, 2-oxoazepinyl, oxazolyl,
2-oxopiperazinyl, 2-oxopiperdinyl, 2-oxopyrrolidinyl, piperidyl,
piperazinyl, pyridyl, pyrazinyl, pyrazolidinyl, pyrazolyl,
pyridazinyl, pyrimidinyl, pyrrolidinyl, pyrrolyl, quinazolinyl,
quinolinyl, quinoxalinyl, tetrahydrofuryl, tetrahydroisoquinolinyl,
tetrahydroquinolinyl, thiamorpholinyl, thiamorpholinyl sulfoxide,
thiazolyl, thiazolinyl, thienofuryl, thienothienyl, and thienyl. An
embodiment of the examples of such heterocyclic elements include,
but are not limited to, azepinyl, benzimidazolyl, benzisoxazolyl,
benzofurazanyl, benzopyranyl, benzothiopyranyl, benzofuryl,
benzothiazolyl, benzothienyl, benzoxazolyl, chromanyl, cinnolinyl,
dihydrobenzofuryl, dihydrobenzothienyl, dihydrobenzothiopyranyl,
dihydrobenzothiopyranyl sulfone, furyl, imidazolidinyl,
imidazolinyl, imidazolyl, indolinyl, indolyl, isochromanyl,
isoindolinyl, isoquinolinyl, isothiazolidinyl, isothiazolyl,
isothiazolidinyl, morpholinyl, naphthyridinyl, oxadiazolyl,
2-oxoazepinyl, oxazolyl, 2-oxopiperazinyl, 2-oxopiperdinyl,
2-oxopyrrolidinyl, piperidyl, piperazinyl, pyridyl, 2-pyridinonyl,
pyrazinyl, pyrazolidinyl, pyrazolyl, pyridazinyl, pyrimidinyl,
pyrrolidinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl,
tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydroquinolinyl,
thiamorpholinyl, thiamorpholinyl sulfoxide, thiazolyl, thiazolinyl,
thienofuryl, thienothienyl, thienyl and triazolyl. Unless otherwise
specified, the hetercyclyl ring can be unsubstituted or substituted
with one or more of C.sub.1-4 alkyl, hydroxy, C.sub.1-4 alkoxy,
amino, and halogen, e.g. F, Cl, Br, or I.
[0241] The term "a disubstituted aryl or heteroaryl ring" includes
aryl and heteroaryl rings in which two ring carbon atoms have
substituents attached and do not have hydrogen atoms attached, e.g.
2,5-substituted thiophene, furan, and thiazole, and 1,2-, 1,3- and
1,4-substituted benzene. Such disubstituted rings include, but are
not limited to, those structurally depicted as ##STR7##
[0242] In a preferred embodiment, the disubstituted aryl ring is
##STR8##
[0243] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR9##
[0244] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR10##
[0245] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR11##
[0246] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR12##
[0247] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR13##
[0248] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR14##
[0249] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR15##
[0250] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR16##
[0251] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR17##
[0252] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR18##
[0253] In another preferred embodiment, the disubstituted
heteroaryl ring is ##STR19##
[0254] The term "substituted," as used herein, means that any one
or more hydrogens on the designated atom is replaced with a
selection from the indicated group, provided that the designated
atom's normal valency is not exceeded, and that the substitution
results in a stable compound. When a substituent is keto (i.e.,
.dbd.O), then 2 hydrogens on the atom are replaced.
[0255] The term "agonist" as used herein means EP.sub.4 subtype
compounds of formula I interact with the EP4 receptor to produce
maximal, super maximal or submaximal effects compared to the
natural agonist, PGE2. See Goodman and Gilman, The Pharmacological
Basis of Therapeutics, 9.sup.th edition, 1996, chapter 2.
[0256] Another embodiment of this invention is directed to a
composition containing an EP.sub.4 agonist of Formula I and
optionally a pharmaceutically acceptable carrier.
[0257] Yet another embodiment of this invention is directed to a
method for decreasing elevated intraocular pressure or treating
glaucoma by administration, preferably topical or intra-camaral
administration, of a composition containing an EP.sub.4 agonist of
Formula I and optionally a pharmaceutically acceptable carrier. Use
of the compounds of formula I for the manufacture of a medicament
for treating elevated intraocular pressure or glaucoma or a
combination thereof is also included in this invention.
[0258] This invention is further concerned with a process for
making a pharmaceutical composition comprising a compound of
formula I.
[0259] This invention is further concerned with a process for
making a pharmaceutical composition comprising a compound of
formula I, and a pharmaceutically acceptable carrier.
[0260] The claimed compounds bind strongly and act on PGE.sub.2
receptor, particularly on the EP.sub.4 subtype receptor and
therefore are useful for preventing and/or treating glaucoma and
ocular hypertension.
[0261] Dry eye is a common ocular surface disease afflicting
millions of people. Although it appears that dry eye may result
from a number of unrelated pathogenic causes, the common end result
is the breakdown of the tear film, which results in dehydration of
the exposed outer surface of the eye. (Lemp, Report of the Nation
Eye Institute/Industry Workshop on Clinical Trials in Dry Eyes, The
CLAO Journel, 21(4):221-231 (1995)). One cause for dry eye is the
decreased mucin production by the conjunctival cells and/or corneal
epithelial cells of mucin, which protects and lubricates the ocular
surface (Gipson and Inatomi, Mucin genes expressed by ocular
surface epithelium. Progress in Retinal and Eye Research, 16:81-98
(1997)). Functional EP4 receptors have been found in human
conjuctival epithelial cells (see U.S. Pat. No. 6,344,477,
incorporated by reference in its entirey) and it is appreciated
that both human corneal epithelial cells (Progess in Retinal and
Eye Research, 16:81-98(1997)) and conjuctival cells (Dartt et al.
Localization of nerves adjacent to goblet cells in rat conjucntiva.
Current Eye Research, 14:993-1000 (1995)) are capable of secreting
mucins. Thus, the compounds of formula I are useful for treating
dry eye.
[0262] Macular edema is swelling within the retina within the
critically important central visual zone at the posterior pole of
the eye. An accumulation of fluid within the retina tends to detach
the neural elements from one another and from their local blood
supply, creating a dormancy of visual function in the area. It is
believed that EP.sub.4 agonist which lower IOP are useful for
treating diseases of the macular such as macular edema or macular
degeneration. Thus, another aspect of this invention is a method
for treating macular edema or macular degeneration.
[0263] Glaucoma is characterized by progressive atrophy of the
optic nerve and is frequently associated with elevated intraocular
pressure (IOP). It is possible to treat glaucoma, however, without
necessarily affecting IOP by using drugs that impart a
neuroprotective effect. See Arch. Ophthalmol. Vol. 112, January
1994, pp. 37-44; Investigative Ophthamol. & Visual Science, 32,
5, Apr. 1991, pp. 1593-99. It is believed that EP.sub.4 agonist
which lower IOP are useful for providing a neuroprotective effect.
They are also believed to be effective for increasing retinal and
optic nerve head blood velocity and increasing retinal and optic
nerve oxygen by lowering IOP, which when coupled together benefits
optic nerve health. As a result, this invention further relates to
a method for increasing retinal and optic nerve head blood
velocity, or increasing retinal and optic nerve oxygen tension or
providing a neuroprotective effect or a combination thereof by
using an EP.sub.4 agonist of formula I.
[0264] The compounds produced in the present invention are readily
combined with suitable and known pharmaceutically acceptable
excipients to produce compositions which may be administered to
mammals, including humans, to achieve effective IOP lowering. Thus,
this invention is also concerned with a method of treating ocular
hypertension or glaucoma by administering to a patient in need
thereof one of the compounds of formula I alone or in combination
with a .beta.-adrenergic blocking agent such as timolol, betaxolol,
levobetaxolol, carteolol, levobunolol, a parasympathomimetic agent
such as pilocarpine, a sympathomimetic agents such as epinephrine,
iopidine, brimonidine, clonidine, para-aminoclonidine, a carbonic
anhydrase inhibitor such as dorzolamide, acetazolamide,
metazolamide or brinzolamide; a prostaglandin such as latanoprost,
travaprost, unoprostone, rescula, S1033 (compounds set forth in
U.S. Pat. Nos. 5,889,052; 5,296,504; 5,422,368; and 5,151,444); a
hypotensive lipid such as lumigan and the compounds set forth in
U.S. Pat. No. 5,352,708; a neuroprotectant disclosed in U.S. Pat.
No. 4,690,931, particularly eliprodil and R-eliprodil as set forth
in WO 94/13275, including memantine; or an agonist of 5-HT2
receptors as set forth in PCT/US00/31247, particularly
1-(2-aminopropyl)-3-methyl-1H-imdazol-6-ol fumarate and
2-(3-chloro-6-methoxy-indazol-1-yl)-1-methyl-ethylamine.
[0265] This invention is also concerned with a method for
increasing retinal and optic nerve head blood velocity, or
increasing retinal and optic nerve oxygen tension or providing a
neuroprotective effect or a combination thereof by administering to
a patient in need thereof one of the compounds of formula I alone
or in combination with a .beta.-adrenergic blocking agent such as
timolol, betaxolol, levobetaxolol, carteolol, levobunolol, a
parasympathomimetic agent such as pilocarpine, a sympathomimetic
agents such as epinephrine, iopidine, brimonidine, clonidine,
para-aminoclonidine, a carbonic anhydrase inhibitor such as
dorzolamide, acetazolamide, metazolamide or brinzolamide; a
prostaglandin such as latanoprost, travaprost, unoprostone,
rescula, S1033 (compounds set forth in U.S. Pat. Nos. 5,889,052;
5,296,504; 5,422,368; and 5,151,444); a hypotensive lipid such as
lumigan and the compounds set forth in U.S. Pat. No. 5,352,708; a
neuroprotectant disclosed in U.S. Pat. No. 4,690,931, particularly
eliprodil and R-eliprodil as set forth in WO 94/13275, including
memantine; or an agonist of 5-HT2 receptors as set forth in
PCT/US00/31247, particularly
1-(2-aminopropyl)-3-methyl-1H-imdazol-6-ol fumarate and
2-(3-chloro-6-methoxy-indazol-1-yl)-1-methyl-ethylamine. Use of the
compounds of formula I for the manufacture of a medicament for
increasing retinal and optic nerve head blood velocity, or
increasing retinal and optic nerve oxygen tension or providing a
neuroprotective effect or a combination thereof is also included in
this invention.
[0266] This invention is further concerned with a method for
treating macular edema or macular degeneration by administering to
a patient in need thereof one of the compounds of formula I alone
or in combination with a .beta.-adrenergic blocking agent such as
timolol, betaxolol, levobetaxolol, carteolol, levobunolol, a
parasympathomimetic agent such as pilocarpine, a sympathomimetic
agents such as epinephrine, iopidine, brimonidine, clonidine,
para-aminoclonidine, a carbonic anhydrase inhibitor such as
dorzolamide, acetazolamide, metazolamide or brinzolamide; a
prostaglandin such as latanoprost, travaprost, unoprostone,
rescula, S1033 (compounds set forth in U.S. Pat. Nos. 5,889,052;
5,296,504; 5,422,368; and 5,151,444); a hypotensive lipid such as
lumigan and the compounds set forth in U.S. Pat. No. 5,352,708; a
neuroprotectant disclosed in U.S. Pat. No. 4,690,931, particularly
eliprodil and R-eliprodil as set forth in WO 94/13275, including
memantine; or an agonist of 5-HT2 receptors as set forth in
PCT/US00/31247, particularly
1-(2-aminopropyl)-3-methyl-1H-imdazol-6-ol fumarate and
2-(3-chloro-6-methoxy-indazol-1-yl)-1-methyl-ethylamine. Use of the
compounds of formula I for the manufacture of a medicament for
macular edema or macular degeneration is also included in this
invention.
[0267] Compounds of the invention may also be used to treat
neuropathic pain. Neuropathic pain syndromes can develop following
neuronal injury and the resulting pain may persist for months or
years, even after the original injury has healed. Neuronal injury
may occur in the peripheral nerves, dorsal roots, spinal cord or
certain regions in the brain. Neuropathic pain syndromes are
traditionally classified according to the disease or event that
precipitate them. Neuropathic pain syndromes include: diabetic
neuropathy; sciatica; non-specific lower back pain; multiple
sclerosis pain; fibromyalgia; HIV-related neuropathy, post-herpetic
neuralgia; trigeminal neuralgia; and pain resulting from physical
trauma, amputation, cancer, toxins or chronic inflammatory
conditions. These conditions are difficult to treat and although
several drugs are known to have limited efficacy, complete pain
control is rarely achieved. The symptoms of neuropathic pain are
incredibly heterogeneous and are often described as spontaneous
shooting and lancinating pain, or ongoing, burning pain. In
addition, there is pain associated with normally non-painful
sensations such as "pins and needles" (paraesthesias and
dysesthesias), increased sensitivity to noxious stimuli (thermal,
cold, mechanical hyperalgesia), continuing pain sensation after
removal of the stimulation (hyperpathia) or an absence of or
deficit in selective sensory pathways (hypoalgesia).
[0268] Compounds of the invention may also be used to treat acute
renal failure, chronic renal failure, colon cancer, colitis, and
HIV latency.
[0269] The EP.sub.4 agonist used in the instant invention can be
administered in a therapeutically effective amount intravaneously,
subcutaneously, topically, transdermally, parenterally or any other
method known to those skilled in the art. Ophthalmic pharmaceutical
compositions are preferably adapted for topical administration to
the eye in the form of solutions, suspensions, ointments, creams or
as a solid insert. Ophthalmic formulations of this compound may
contain from 0.001 to 5% and especially 0.001 to 0.1% of
medicament. Higher dosages as, for example, up to about 10% or
lower dosages can be employed provided the dose is effective in
reducing intraocular pressure, treating glaucoma, increasing blood
flow velocity or oxygen tension. For a single dose, from between
0.001 to 5.0 mg, preferably 0.005 to 2.0 mg, and especially 0.005
to 1.0 mg of the compound can be applied to the human eye.
[0270] The pharmaceutical preparation which contains the compound
may be conveniently admixed with a non-toxic pharmaceutical organic
carrier, or with a non-toxic pharmaceutical inorganic carrier.
Typical of pharmaceutically acceptable carriers are, for example,
water, mixtures of water and water-miscible solvents such as lower
alkanols or aralkanols, vegetable oils, peanut oil, polyalkylene
glycols, petroleum based jelly, ethyl cellulose, ethyl oleate,
carboxymethyl-cellulose, polyvinylpyrrolidone, isopropyl myristate
and other conventionally employed acceptable carriers. The
pharmaceutical preparation may also contain non-toxic auxiliary
substances such as emulsifying, preserving, wetting agents, bodying
agents and the like, as for example, polyethylene glycols 200, 300,
400 and 600, carbowaxes 1,000, 1,500, 4,000, 6,000 and 10,000,
antibacterial components such as quaternary ammonium compounds,
phenylmercuric salts known to have cold sterilizing properties and
which are non-injurious in use, thimerosal, methyl and propyl
paraben, benzyl alcohol, phenyl ethanol, buffering ingredients such
as sodium borate, sodium acetates, gluconate buffers, and other
conventional ingredients such as sorbitan monolaurate,
triethanolamine, oleate, polyoxyethylene sorbitan monopalmitylate,
dioctyl sodium sulfosuccinate, monothioglycerol, thiosorbitol,
ethylenediamine tetracetic acid, and the like. Additionally,
suitable ophthalmic vehicles can be used as carrier media for the
present purpose including conventional phosphate buffer vehicle
systems, isotonic boric acid vehicles, isotonic sodium chloride
vehicles, isotonic sodium borate vehicles and the like. The
pharmaceutical preparation may also be in the form of a
microparticle formulation. The pharmaceutical preparation may also
be in the form of a solid insert. For example, one may use a solid
water soluble polymer as the carrier for the medicament. The
polymer used to form the insert may be any water soluble non-toxic
polymer, for example, cellulose derivatives such as
methylcellulose, sodium carboxymethyl cellulose, (hydroxyloweralkyl
cellulose), hydroxyethyl cellulose, hydroxypropyl cellulose,
hydroxypropylmethyl cellulose; acrylates such as polyacrylic acid
salts, ethylacrylates, polyactylamides; natural products such as
gelatin, alginates, pectins, tragacanth, karaya, chondrus, agar,
acacia; the starch derivatives such as starch acetate,
hydroxymethyl starch ethers, hydroxypropyl starch, as well as other
synthetic derivatives such as polyvinyl alcohol, polyvinyl
pyrrolidone, polyvinyl methyl ether, polyethylene oxide,
neutralized carbopol and xanthan gum, gellan gum, and mixtures of
said polymer.
[0271] Suitable subjects for the administration of the formulation
of the present invention include primates, man and other animals,
particularly man and domesticated animals such as cats, rabbits and
dogs.
[0272] The pharmaceutical preparation may contain non-toxic
auxiliary substances such as antibacterial components which are
non-injurious in use, for example, thimerosal, benzalkonium
chloride, methyl and propyl paraben, benzyldodecinium bromide,
benzyl alcohol, or phenylethanol; buffering ingredients such as
sodium chloride, sodium borate, sodium acetate, sodium citrate, or
gluconate buffers; and other conventional ingredients such as
sorbitan monolaurate, triethanolamine, polyoxyethylene sorbitan
monopalmitylate, ethylenediamine tetraacetic acid, and the
like.
[0273] The ophthalmic solution or suspension may be administered as
often as necessary to maintain an acceptable IOP level in the eye.
It is contemplated that administration to the mammalian eye will be
from once up to three times daily.
[0274] For topical ocular administration the novel formulations of
this invention may take the form of solutions, gels, ointments,
suspensions or solid inserts, formulated so that a unit dosage
comprises a therapeutically effective amount of the active
component or some multiple thereof in the case of a combination
therapy.
[0275] The compounds of the instant invention are also useful for
mediating the bone modeling and remodeling processes of the
osteoblasts and osteoclasts. See PCT US99/23757 filed Oct. 12, 1999
and incorporated herein by reference in its entirety. The major
prostaglandin receptor in bone is EP.sub.4, which is believed to
provide its effect by signaling via cyclic AMP. See Ikeda T,
Miyaura C, Ichikawa A, Narumiya S, Yoshiki S and Suda T 1995, In
situ localization of three subtypes (EP.sub.2, EP.sub.3 and
EP.sub.4) of prostaglandin E receptors in embryonic and newborn
mice., J Bone Miner Res 10 (sup 1):S172, which is incorporated by
reference herein in its entirety. Use of the compounds of formula I
for the manufacture of a medicament for mediating the bone modeling
and remodeling processes are also included in this invention
[0276] Thus, another object of the present invention is to provide
methods for stimulating bone formation, i.e. osteogenesis, in a
mammal comprising administering to a mammal in need thereof a
therapeutically effective amount of an EP.sub.4 receptor subtype
agonist of formula I.
[0277] Still another object of the present invention to provide
methods for stimulating bone formation in a mammal in need thereof
comprising administering to said mammal a therapeutically effective
amount of an EP.sub.4 receptor subtype agonist of formula I and a
bisphosphonate active. Use of the compounds of formula I for the
manufacture of a medicament for stimulating bone formation is also
included in this invention.
[0278] Yet another object of the present invention to provide
pharmaceutical compositions comprising a therapeutically effective
amount of an EP.sub.4 receptor subtype agonist of formula I and a
bisphosphonate active.
[0279] It is another object of the present invention to provide
methods for treating or reducing the risk of contracting a disease
state or condition related to abnormal bone resorption in a mammal
in need of such treatment or prevention, comprising administering
to said mammal a therapeutically effective amount of an EP.sub.4
receptor subtype agonist of formula I. Use of the compounds of
formula I for the manufacture of a medicament for treating or
reducing the risk of contracting a disease state or condition
related to abnormal bone resorption is also included in this
invention.
[0280] The disease states or conditions related to abnormal bone
resorption include, but are not limited to, osteoporosis,
glucocorticoid induced osteoporosis, Paget's disease, abnormally
increased bone turnover, periodontal disease, tooth loss, bone
fractures, rheumatoid arthritis, periprosthetic osteolysis,
osteogenesis imperfecta, metastatic bone disease, hypercalcemia of
malignancy, and multiple myeloma.
[0281] Within the method comprising administering a therapeutically
effective amount of an EP.sub.4 receptor subtype agonist of formula
I and a bisphosphonate active, both concurrent and sequential
administration of the EP.sub.4 receptor subtype agonist of formula
I and the bisphosphonate active are deemed within the scope of the
present invention. Generally, the formulations are prepared
containing 5 or 10 mg of a bisphosphonate active, on a
bisphosphonic acid active basis. With sequential administration,
the agonist and the bisphosphonate can be administered in either
order. In a subclass of sequential administration the agonist and
bisphosphonate are typically administered within the same 24 hour
period. In yet a further subclass, the agonist and bisphosphonate
are typically administered within about 4 hours of each other.
[0282] Nonlimiting examples of bisphosphonate actives useful herein
include the following:
[0283] Alendronic acid,
4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid;
[0284] Alendronate (also known as alendronate sodium or alendronate
monosodium trihydrate),
4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid monosodium
trihydrate;
[0285] Alendronic acid and alendronate are described in U.S. Pat.
No. 4,922,007, to Kieczykowski et al., issued May 1, 1990; U.S.
Pat. No. 5,019,651, to Kieczykowski et al., issued May 28, 1991;
U.S. Pat. No. 5,510,517, to Dauer et al., issued Apr. 23, 1996;
U.S. Pat. No. 5,648,491, to Dauer et al., issued Jul. 15, 1997, all
of which are incorporated by reference herein in their
entirety;
[0286] Cycloheptylaminomethylene-1,1-bisphosphonic acid, YM 175,
Yamanouchi (cimadronate), as described in U.S. Pat. No. 4,970,335,
to Isomura et al., issued Nov. 13, 1990, which is incorporated by
reference herein in its entirety;
[0287] 1,1-dichloromethylene-1,1-diphosphonic acid (clodronic
acid), and the disodium salt (clodronate, Procter and Gamble), are
described in Belgium Patent 672,205 (1966) and J. Org. Chem 32,
4111 (1967), both of which are incorporated by reference herein in
their entirety;
[0288] 1-hydroxy-3-(1-pyrrolidinyl)-propylidene-1,1-bisphosphonic
acid (EB- 1053);
[0289] 1-hydroxyethane-1,1-diphosphonic acid (etidronic acid);
[0290]
1-hydroxy-3-(N-methyl-N-pentylamino)propylidene-1,1-bisphosphonic
acid, also known as BM-210955, Boehringer-Mannheim (ibandronate),
is described in U.S. Pat. No. 4,927,814, issued May 22, 1990, which
is incorporated by reference herein in its entirety;
[0291] 6-amino-1-hydroxyhexylidene-1,1-bisphosphonic acid
(neridronate);
[0292] 3-(dimethylamino)-1-hydroxypropylidene-1,1-bisphosphonic
acid (olpadronate);
[0293] 3-amino-1-hydroxypropylidene-1,1-bisphosphonic acid
(pamidronate);
[0294] [2-(2-pyridinyl)ethylidene]-1,1-bisphosphonic acid
(piridronate) is described in U.S. Pat. No. 4,761,406, which is
incorporated by reference in its entirety;
[0295] 1-hydroxy-2-(3-pyridinyl)-ethylidene-1,1-bisphosphonic acid
(risedronate);
[0296] (4-chlorophenyl)thiomethane-1,1-disphosphonic acid
(tiludronate) as described in U.S. Pat. No. 4,876,248, to Breliere
et al., Oct. 24, 1989, which is incorporated by reference herein in
its entirety; and
[0297] 1-hydroxy-2-(1H-imidazol-1-yl)ethylidene-1,1-bisphosphonic
acid (zolendronate).
[0298] A non-limiting class of bisphosphonate actives useful in the
instant invention are selected from the group consisting of
alendronate, cimadronate, clodronate, tiludronate, etidronate,
ibandronate, neridronate, olpandronate, risedronate, piridronate,
pamidronate, zolendronate, pharmaceutically acceptable salts
thereof, and mixtures thereof.
[0299] A non-limiting subclass of the above-mentioned class in the
instant case is selected from the group consisting of alendronate,
pharmaceutically acceptable salts thereof, and mixtures
thereof.
[0300] A non-limiting example of the subclass is alendronate
monosodium trihydrate.
[0301] In the present invention, as it relates to bone stimulation,
the agonist is typically administered for a sufficient period of
time until the desired therapeutic effect is achieved. The term
"until the desired therapeutic effect is achieved", as used herein,
means that the therapeutic agent or agents are continuously
administered, according to the dosing schedule chosen, up to the
time that the clinical or medical effect sought for the disease or
condition being mediated is observed by the clinician or
researcher. For methods of treatment of the present invention, the
compounds are continuously administered until the desired change in
bone mass or structure is observed. In such instances, achieving an
increase in bone mass or a replacement of abnormal bone structure
with normal bone structure are the desired objectives. For methods
of reducing the risk of a disease state or condition, the compounds
are continuously administered for as long as necessary to prevent
the undesired condition. In such instances, maintenance of bone
mass density is often the objective.
[0302] Nonlimiting examples of administration periods can range
from about 2 weeks to the remaining lifespan of the mammal. For
humans, administration periods can range from about 2 weeks to the
remaining lifespan of the human, preferably from about 2 weeks to
about 20 years, more preferably from about 1 month to about 20
years, more preferably from about 6 months to about 10 years, and
most preferably from about 1 year to about 10 years.
[0303] The instant compounds are also useful in combination with
known agents useful for treating or preventing bone loss, bone
fractures, osteoporosis, glucocorticoid induced osteoporosis,
Paget's disease, abnormally increased bone turnover, periodontal
disease, tooth loss, osteoarthritis, rheumatoid arthritis,,
periprosthetic osteolysis, osteogenesis imperfecta, metastatic bone
disease, hypercalcemia of malignancy, and multiple myeloma.
Combinations of the presently disclosed compounds with other agents
useful in treating or preventing osteoporosis or other bone
disorders are within the scope of the invention. A person of
ordinary skill in the art would be able to discern which
combinations of agents would be useful based on the particular
characteristics of the drugs and the disease involved. Such agents
include the following: an organic bisphosphonate; a cathepsin K
inhibitor; an estrogen or an estrogen receptor modulator; an
androgen receptor modulator; an inhibitor of osteoclast proton
ATPase; an inhibitor of HMG-CoA reductase; an integrin receptor
antagonist; an osteoblast anabolic agent, such as PTH; calcitonin;
Vitamin D or a synthetic Vitamin D analogue; and the
pharmaceutically acceptable salts and mixtures thereof. A preferred
combination is a compound of the present invention and an organic
bisphosphonate. Another preferred combination is a compound of the
present invention and an estrogen receptor modulator. Another
preferred combination is a compound of the present invention and an
estrogen. Another preferred combination is a compound of the
present invention and an androgen receptor modulator. Another
preferred combination is a compound of the present invention and an
osteoblast anabolic agent.
[0304] Regarding treatment of abnormal bone resorption and ocular
disorders, the formula I agonists generally have an EC.sub.50 value
from about 0.001 nM to about 100 microM, although agonists with
activities outside this range can be useful depending upon the
dosage and route of administration. In a subclass of the present
invention, the agonists have an EC.sub.50 value of from about 0.01
microM to about 10 microM. In a further subclass of the present
invention, the agonists have an EC.sub.50 value of from about 0.1
microM to about 10 microM. EC.sub.50 is a common measure of agonist
activity well known to those of ordinary skill in the art and is
defined as the concentration or dose of an agonist that is needed
to produce half, i.e. 50%, of the maximal effect. See also, Goodman
and Gilman's, The Pharmacologic Basis of Therapeutics, 9th edition,
1996, chapter 2, E. M. Ross, Pharmacodynamics, Mechanisms of Drug
Action and the Relationship Between Drug Concentration and Effect,
and PCT US99/23757, filed Oct. 12, 1999, which are incoroporated by
reference herein in their entirety.
[0305] The herein examples illustrate but do not limit the claimed
invention. Each of the claimed compounds are EP.sub.4 agonists and
are useful for a number of physiological ocular and bone
disorders.
[0306] The compounds of this invention can be made, with some
modification, in accordance with U.S. Pat. No. 6,043,275,
EP0855389, and WO 01/46140, all of which are incorporated herein by
reference in their entirety. The following non-limiting examples,
given by way of illustration, is demonstrative of the present
invention.
[0307] Compounds stated in the present invention can be prepared
according to the following general scheme. ##STR20##
[0308] The variables are as defined in Formula I.
[0309] Some abbreviations that may appear in this application are
as follows: TABLE-US-00001 Designation ABBREVIATIONS CDI
1,1'-carbonyldiimidazole DHP 4-dihydro-2H-pyran LiOH lithium
hydroxide NaBH4 sodium borohydride NaH sodium hydride nBu3SnN3
azidotributyltin. PG protecting groups TBSCl
tert-butyldimethylsilyl chloride TsOH p-toluenesulfonic acid
[0310] Preparation of compounds in the present invention is further
illustrated by the following specific examples.
EXAMPLE 1
7-{4-[(1E,3S)-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidin-3-yl}hept-
anoic acid (1-10) and
7-{4-[(1E,3R)-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidin-3-yl}hep-
tanoic acid (1-11)
Step 1: 4-methoxycarbonyloxazolidin-2-one (1-1)
[0311] The preparation of 1-1 was carried out according to the
literature procedure (see: Sibi, M. P. et al, J. Chem. Soc. Perkin
Trans. 1 1994, 1675). Thus, 39.5 grams of serine methyl ester
hydrochloride was reacted with phosgene (20% solution in toluene,
175 mL) to give 42 grams of desired product. .sup.1H NMR (400 MHz,
acetone-d.sub.6): .delta. 7.1 (br s, 1H, NH), 4.64-4.56 (m, 2H),
4.44 (dd, 1H), 3.77 (s, 3H).
Step 2: N-Boc-4-methoxycarbonyloxazolidin-2-one (1-2)
[0312] The preparation of this compound was carried out according
to the method described by Ishizuka and Kunieda (see: Tetrahedron
Lett. 1987, 28, 4185). Thus, to a solution of 1-1 (1 g, 6.9 mmol)
in THF was added di-t-butyl dicarbonate (1.81 g), triethylamine
(1.16 mL) and DMAP (84 mg). The solution was stirred at room
temperature overnight and diluted with water/ethyl acetate. The
organic layer was separated, washed with IN HCl, half saturated
NaHCO.sub.3 and brine. The crude product thus obtained was used
without further purification. .sup.1H NMR (500 MHz,
acetone-d.sub.6): .delta. 4.92 (dd, 1H), 4.62 (t, 1H), 4.35 (dd,
1H), 3.80 (s, 3H), 1.46 (s, 9H).
Step 3: tert-Butyl (2-oxo-1,3-oxazolidin-4-yl)methyl carbonate
(1-3)
[0313] To a solution of 1-2 (6.9 mmol) in ethanol/THF at 0.degree.
C. was added NaBH.sub.4 (522 mg) and the mixture was allowed to
warm slowly to room temperature and then quenched with saturated
NH.sub.4Cl and extracted with ethyl acetate. Purification by column
chromatography (70%-100% ethyl acetate in hexanes) afforded
compound 1-3 as a white solid. .sup.1H NMR (400 MHz,
acetone-d.sub.6): .delta. 6.81 (br s, 1H, NH), 4.50 (t, 1H), 4.20
(m, 3H), 4.10 (dd, 1H), 1.46 (s, 9H); MS (+ESI): m/z 218.1
[M+1].sup.+.
Step 4: Ethyl
7-(4-{[(tert-butoxycarbonyl)oxy]methyl}-2-oxo-1,3-oxazolidin-3-yl)heptano-
ate (1-4)
[0314] To a solution of 1-3 (340 mg) and KI (240 mg) in DMF (16 mL)
was added NaH (69 mg) and the mixture was stirred at room
temperature for 1 h. To the mixture was then added ethyl
7-bromoheptanoate (247 mg) and the mixture was heated to 70.degree.
C. overnight. After cooling to room temperature, the mixture was
diluted with ether/water and extracted with ether (3.times.). The
organic layer was washed with water, brine and dried over
Na.sub.2SO.sub.4. The crude was purified by flash chromatography.
Eluting with 50% ethyl acetate in hexanes gave the desired product.
.sup.1H NMR (500 MHz, acetone-d.sub.6): .delta. 4.43-4.34 (m, 2H),
4.19-4.11 (m, 3H), 4.09 (q, 2H), 3.40 (m, 1H), 3.17 (m, 1H), 2.30
(t, 2H), 1.70-1.50 (m, 4H), 1.47 (s, 9H), 1.40-1.30 (m, 4H), 1.22
(t, 3H).
Step 5: Ethyl
7-[4-(hydroxymethyl)-2-oxo-1,3-oxazolidin-3-yl]heptanoate (1-5)
[0315] A solution of 1-4 (446 mg) in a mixture of 10% TFA in
dichloromethane (10 mL) was stirred at room temperature for 2 h and
concentrated. The residue was purified by column chromatography.
Eluting with 70-100% ethyl acetate in hexanes afforded the alcohol
1-5 (264 mg). .sup.1H NMR (400 MHz, acetone-d.sub.6): .delta. 4.33
(t, 1H), 4.19 (t, 1H, OH), 4.14 (dd, 1H), 4.09 (q, 2H), 3.95 (m,
1H), 3.78 (m, 1H), 3.65 (m, 1H), 3.38 (m, 1H), 3.16 (m, 1H), 2.29
(t, 2H), 1.70-1.55 (m, 4H), 1.45-1.30 (m, 4H), 1.21 (t, 3H).
Step 6: Ethyl
7-{4-[(1E)-3-oxo-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidin-3-yl}heptanoate
(1-6)
[0316] To a solution of alcohol 1-5 (273 mg) in dichloromethane (5
mL) was added Dess-Martin periodinane (451 mg) and the mixture was
stirred at room temperature for 1 h and concentrated. The mixture
was resuspended in ether, filtered and the filtrate was washed with
saturated NaHCO.sub.3 and dried over Na.sub.2SO.sub.4. Filtration
and concentration in vacuo afforded the crude aldehyde Ethyl
7-(4-formyl-2-oxo-1,3-oxazolidin-3-yl)heptanoate (1-7) which was
used directly without further purification. To a suspension of NaH
(47 mg) in THF (6 mL) was added dimethyl
2-oxo-3-phenylpropylphosphonate (282 mg) at 0.degree. C. (formed a
white slurry) and the mixture was stirred for an additional lh. To
the mixture was then added aldehyde 1-7 (145 mg) in THF (4 mL) via
cannula and the resultant mixture stirred at room temperature for 2
h and quenched with saturated NH.sub.4Cl. The mixture was then
extracted with ethyl acetate (3.times.) and the organic layer was
washed with brine, dried over Na.sub.2SO.sub.4, filtered and
concentrated. The residue was purified by chromatography using
ethyl acetate/hexanes (1:1) as the eluent to give the desired
product 1-6.1 H NMR (400 mg, acetone-d.sub.6): .delta. 7.36-7.26
(m, 5H), 6.86 (dd, 1H), 6.43 (d, 1H), 4.57 (m, 1H), 4.50 (t, 1H),
4.12-3.96 (m, 5H), 3.28 (m, 1H), 2.96 (m, 1H), 2.28 (t, 2H),
1.65-1.45 (m, 4H), 1.35-1.25, m, 4H), 1.22 (t, 3H).
Step 7: Ethyl
7-{4-[(1E,3R)-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidin-3-yl}hep-
tanoate (1-8) and Ethyl
7-{4-[(1E,3S)-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-oxazolidin-3-yl}hep-
tanoate (1-9)
[0317] To a solution of ketone 1-6 (128 mg) in methanol/AcOH
(2.5:1, 3.5 mL) was added Na(CN)BH.sub.3 (25 mg) and the mixture
was stirred at room temperature for 2 h and then heated briefly
with a heat gun. The mixture was then quenched with water and
extracted with ethyl acetate (3.times.) and the organic layers was
concentrated and purified by chromatography. Eluting with 50-75%
ethyl acetate in hexanes first gave isomer 1-8. .sup.1H NMR (400
MHz, acetone-d.sub.6): .delta. 7.35-7.15 (m, 5H), 5.92 (dd, 1H),
5.50 (m, 1H), 4.45-4.30 (m, 3H), 4.18 (d, 1H), 4.08 (q, 2H), 3.75
(m, 1H), 3.22 (m, 1H), 3.00-2.80 (m, 3H), 2.29 (t, 2H), 1.65-1.45
(m, 4H), 1.40-1.30 (m, 4H), 1.21 (t, 3H). For convenience, the less
polar isomer was arbitrarily assigned epimer 1-8. Continuous
elution afforded the more polar epimer 1-9. .sup.1H NMR (400 MHz,
acetone-d.sub.6): .delta. 7.35-7.15 (m, 5H), 5.91 (dd, 1H), 5.50
(m, 1H), 4.46-4.29 (m, 3H), 4.15 (d, 1H), 4.08 (q, 2H), 3.82 (dd,
1H), 3.15 (m, 1H), 2.95-2.75 (m, 3H), 2.29 (t, 2H), 1.65-1.25 (m,
8H), 1.22 (t, 3H).
[0318] A mixture of ester 1-9 (22 mg) in methanol (0.7 mL) and
water (0.15 mL) and LiOH (0.062 mL, 1 N) was stirred at room
temperature under N.sub.2 overnight and concentrated to give the
title compound 1-10 as a lithium salt. MS (-ESI): m/z 360.1
(M-1).sup.-. Epimer 1-8 was processed to the title compound 1-11
similarly. MS (-ESI): m/z 360.1 (M-1).sup.-.
EXAMPLE 2
(4S)-4-[(1E,3R)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraa-
zol-5-yl)hexyl]-1,3-oxazolidin-2-one (2-8) and
(4S)-4-[(1E,3S)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetra-
azol-5-yl)hexyl]-1,3-oxazolidin-2-one (2-9)
Step 1: methyl N-(6-cyanohexyl)-D-serinate (2-1)
[0319] To a solution of D-serine methyl ester hydrochloride (0.91
g) in ethanol (18 mL) was added 7-oxoheptanenitrile (0.67 g) and
triethylamine (0.6 mL) (see: Kubodera, N. et al, Heterocycles 1982,
19, 1285) and the mixture was stirred under N.sub.2 for 1 h. To the
solution was then added Na(CN)BH.sub.3 (0.4 g) and the resultant
cloudy suspension was further stirred under N.sub.2 for 1 h. The
mixture was quenched with water and concentrated in vacuo and the
residue diluted with ethyl acetate/saturated NaHCO.sub.3. The
organic layer was separated and the aqueous layer extracted with
ethyl acetate (3.times.). The organic layers were washed with
water, brine, dried over Na.sub.2SO.sub.4 and filtered. The
filtrate was concentrated and the residue was purified by
chromatography. Eluting with 5-10% (v) methanol in dichloromethane
gave the desired product 2-1 (620 mg). .sup.1H NMR (400 MHz,
CDCl.sub.3): .delta. 3.78 (m, 1H), 3.77 (s, 3H), 3.59 (dd, 1H),
3.38 (dd, 1H), 2.72 (m, 1H), 2.53 (m, 1H), 2.36 (t, 2H), 1.70 (m,
2H), 1.55-1.35 (m, 6H).
Step 2: methyl
(4R)-3-(6-cyanohexyl)-2-oxo-1,3-oxazolidine-4-carboxylate (2-2)
[0320] To a solution of amine 2-1 (620 mg) and pyridine (0.48 mL)
in dichloromethane (10 mL) at 0.degree. C. was added a solution of
phosgene in toluene (1.72 mL, 1.9 M) and the mixture was stirred at
the temperature for 1 h. The mixture was diluted with
dichloromethane and washed with 1 N HCl and brine, and dried over
Na.sub.2SO.sub.4. Filtration and concentration of the filtrate gave
the crude product which was purified by chromatography. Eluting
with 60% ethyl acetate in hexanes afforded the desired product 2-2
(560 mg). .sup.1H NMR (400 MHz, acetone-d.sub.6): .delta. 4.61 (dd,
1H), 4.52 (t, 1H), 4.35 (dd, 1H), 3.80 (s, 3H), 3.48 (m, 1H), 3.15
(m, 1H), 2.47 (t, 2H), 1.75-1.35 (m, 8H).
Step 3:
7-[(4S)-4-(hydroxymethyl)-2-oxo-1,3-oxazolidin-3-yl]heptanenitri-
le (2-3)
[0321] To a solution of ester 2-2 (560 mg) in ethanol (5 mL) at
0.degree. C. was added NaBH.sub.4 (38 mg) and the mixture was
stirred at the temperature for 1 h and quenched with half saturated
NaCl. The mixture was concentrated in vacuo to remove the ethanol
and the residue was extracted with ethyl acetate (3.times.). The
organic layers were washed with brine, dried over Na.sub.2SO.sub.4,
filtered and concentrated in vacuo to afford the desired alcohol
2-3 (480 mg). .sup.1H NMR (400 MHz, acetone-d.sub.6): .delta. 4.33
(t, 1H), 4.20-4.12 (m, 2H), 3.96 (m, 1H), 3.79 (m, 1H), 3.65 (m,
1H), 3.40 (m, 1H), 3.17 (m, 1H), 2.47 (t, 2H), 1.70-1.35 (m,
8H).
Step 4:
7-{(4S)-4-[(1E)-4,4-difluoro-3-oxo-4-phenylbut-1-enyl]-2-oxo-1,3-
-oxazolidin-3-yl}heptanenitrile (2-4)
[0322] To a solution of alcohol 2-3 (480 mg) in dichloromethane (10
mL) was added Dess-Martin periodanane (1 g) and the mixture was
stirred at room temperature for lh and concentrated. The residue
was co-evaporated with toluene several times, resuspended in ethyl
acetate and was allowed to sit at 5.degree. C. overnight. The
mixture was filtered and the filtrate was concentrated to give the
crude aldehyde
7-[(4S)-4-formyl-2-oxo-1,3-oxazolidin-3-yl]heptanenitrile (2-5)
which was used directly. To a suspension of NaH (168 mg) in THF was
added dimethyl 3,3-difluoro-2-oxo-3-phenylpropylphosphonate (1.1 g)
dropwise at 0.degree. C. and the mixture was stirred at the
temperature for 30 min. To the mixture was added crude aldehyde 2-5
in THF via a cannula and the mixture was stirred at room
temperature for 5 h and quenched with saturated NH.sub.4Cl. The
mixture was extracted with ethyl acetate and the organic layer was
dried and concentrated. The residue was purified by flash
chromatography to give the desired product 2-4. .sup.1H NMR (400
MHz, acetone-d.sub.6): .delta. 7.70-7.55 (m, 5H), 7.08 (dd, 1H),
6.95 (d, 1H), 4.70 (m, 1H), 4.52 (t, 1H), 3.30 (m, 1H), 3.00 (m,
1H), 2.48 (t, 2H), 1.70-1.25 (m, 8H).
Step 5:
7-{(4S)-4-[(1E,3R)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2--
oxo-1,3-oxazolidin-3-yl}heptanenitrile (2-6) and
7-{(4S)-4-[(1E,3S)-4,4-difluoro-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-o-
xazolidin-3-yl}heptanenitrile (2-7)
[0323] To a solution of ketone 2-4 (100 mg) and
CeCl.sub.3.7H.sub.2O (1 eq) in ethanol/water (4:1) at -20.degree.
C. was added NaBH, (1.2 eq) and the mixture was warmed slowly to
room temperature and quenched with half saturated NaCl. The mixture
was processed as described and the crude was purified by HPLC
(porasil.TM.). Eluting with 60% ethyl acetate in hexanes first
afforded epimer 2-7 in which the OH group was arbitrarily assigned
the 1-orientation for convenience. .sup.1H NMR (400 MHz,
acetone-d.sub.6): .delta. 7.57-7.48 (m, 5H), 5.96 (dd, 1H), 5.77
(m, 1H), 5.20 (d, 1H), 4.70 (m, 1H), 4.45-4.35 (m, 2H), 3.81 (m,
1H), 3.18 (m, 1H), 2.85 (m, 1H), 2.47 (t, 2H), 1.68 (m, 2H),
1.55-1.25 (m, 6H).
[0324] Continuous elution gave isomer 2-6. .sup.1H NMR (400 MHz,
acetone-d.sub.6): .delta. 7.57-7.48 (m, 5H), 5.93 (dd, 1H), 5.77
(m, 1H), 5.12 (d, 1H), 4.70 (m, 1H), 4.45-4.35 (m, 2H), 3.81 (m,
1H), 3.20 (m, 1H), 2.87 (m, 1H), 2.47 (t, 2H), 1.68 (m, 2H),
1.55-1.25 (m, 6H).
Step 6:
[0325] A solution of nitrile 2-6 (24 mg) in toluene (1 mL) and
tributyltin azide (0.2 m) was heated to 120.degree. C. for 5 h and
cooled to room temperature. The mixture was diluted with ethyl
acetate and stirred vigorously with a 5% aqueous solution of KF for
1 h. The mixture was filtered and the filtrate was extracted with
ethyl acetate. The ethyl acetate layer was washed with brine, dried
over Na.sub.2SO.sub.4, filtered and concentrated. The residue was
purified by column chromatography. Eluting with 0-10% methanol in
dichloromethane gave the title compound 2-8. MS (-ESI): m/z 420.3
(M-1).sup.-. Compound 2-9 was prepared from he less polar nitrile
2-7 similarly. MS (-ESI): m/z 420.3 (M-1).sup.-.
EXAMPLE 3
7-{(4S)-4-[(1E)-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazolidin-3-yl}h-
eptanoic acid (3-9)
Step 1: ethyl D-cysteinate (3-1):
[0326] To a solution of D-cysteine (12 g) in 200 mL anhydrous
ethanol was bubbled in anhydrous hydrogen chloride for 15 minutes.
The solution was allowed to stir at room temperature overnight
afterwhich it was concentrated in vacuo to yield 13 g (93%) of 3-1
as a white solid whose .sup.1H NMR data was identical to that
reported in the literature.
Step 2: ethyl (4R)-2-oxo-1,3-thiazolidine-4-carboxylate (3-2):
[0327] To a solution of 3-1 (8.5 g, 22.6 mmol) in 200 mL THF was
added of carbonyl diimidazole (12.5 g) and the solution was stirred
overnight at room temperature. The solution was concentrated in
vacuo, 200 mL of 5% Na.sub.2CO.sub.3 was added and the solution
stirred for one hour whereupon 6M HCl was added until the pH of the
solution remained at 2. The solution was extracted with EtOAc, the
organic phases were then combined, dried over MgSO.sub.4, filtered
and concentrated in vacuo. The compound was purified by flash
chromatography using 40% EtOAc/hexanes to yield 6.7 g of 3-2 as a
colorless oil. .sup.1H NMR (400 MHz, acetone-d.sub.6): .delta. 7.5
(br s, 1H), 4.5 (dd, 1H), 4.2 (q, 2H), 3.8 (dd, 1H), 3.6 (dd, 1H),
1.2 (t, 3H).
Step 3: (4S)-4-(hydroxymethyl)-1,3-thiazolidin-2-one (3-3):
[0328] To a solution of 3-2 (6.8 g, 38.6 mmol) in 100 mL ethanol
was added sodium borohydride (3.8 g, 100 mmol) at 0.degree. C. The
solution was stirred for 2 hours as it warmed to rt. The solution
was slowly poured into saturated aqueous ammonium chloride solution
and the solution was extracted with ethyl acetate (5.times.). The
organic phases were then combined, dried over MgSO.sub.4, filtered
and concentrated in vacuo. The compound was purified by flash
chromatography using 0-10% methanol/ethyl acetate to yield 3.3 g of
3-3 as a colorless oil. .sup.1H NMR (400 MHz, acetone-d.sub.6):
.delta. 7.0 (br s, 1H), 4.2 (t, 1H), 4.0 (m, 1H), 3.6 (m, 2H), 3.5
(dd, 1H), 3.3 (dd, 1H).
Step 4:
(4S)-4-[(tetrahydro-2H-pyran-2-yloxy)methyl]-1,3-thiazolidin-2-o-
ne (3-4):
[0329] To a solution of 3-3 (3.3 g, 25 mmol) and 20 mg of
p-toluenesulfonic acid in CH.sub.2Cl.sub.2 (100 mL) was added
3,4-dihydro-2H-pyran (2.7 mL, 30 mmol) and the resulting solution
was stirred at rt for 30 minutes. Triethylamine (0.1 mL) was added
and the solution was concentrated in vacuo. The compound was
purified by flash chromatography using 40% EtOAc/hexanes to yield 4
g of 3-4 as a colorless oil. .sup.1H NMR (400 MHz,
acetone-d.sub.6): .delta. 7.0 (br s, 1H), 4.6 (s, 1H), 4.0 (m, 1H),
3.8 (m, 2H), 3.6 (m, 3H), 3.3 (dd, 1H), 1.9-1.4 (m, 6H).
Step 5: ethyl
7-{(4S)-2-oxo-4-[(tetrahydro-2H-pyran-2-yloxy)methyl]-1,3-thiazolidin-3-y-
l}heptanoate (3-5):
[0330] To a solution of 3-4 (0.5 g, 2.3 mmol) in 10 mL DMF was
added 60% sodium hydride (100 mg, 2.5 mmol) and the resulting
solution was stirred for 1 hour whereupon ethyl-7-bromohepatanoate
(1.2 g, 5 mmol) was added. The solution was heated to 70.degree. C.
and stirred overnight. The solution was then cooled to room
temperature, slowly poured into saturated aqueous ammonium chloride
solution and was extracted with 9:1 hexanes:CH.sub.2Cl.sub.2. The
organic phases were then combined, dried over MgSO.sub.4, filtered
and concentrated in vacuo. The compound was purified by flash
chromatography using 20-50% ethyl acetate/hexanes to yield 500 mg
of 3-5 as a colorless oil. .sup.1H NMR (400 MHz, acetone-d.sub.6):
.delta. 4.7 (s, 1H), 4.1 (m, 3H), 3.8 (m, 2H), 3.5 (m, 4H), 3.2 (m,
2H), 2.3 (m, 2H), 1.9-1.3 (m, 14H), 1.2 (m, 3H).
Step 6: ethyl
7-[(4S)-4-(hydroxymethyl)-2-oxo-1,3-thiazolidin-3-yl]heptanoate
(3-6):
[0331] To a solution of 3-5 (0.5 g, 2.3 mmol) in 10 mL EtOH was
added p-toluene sulfonic acid (50 mg) and the resulting solution
was stirred overnight at room temperature Triethylamine (0.1 mL)
was added and the solution was concentrated in vacuo. The compound
was purified by flash chromatography using 80% EtOAc/hexanes to
yield 0.4 g of 3-6 as a colorless oil. .sup.1H NMR (400 MHz,
acetone-d.sub.6): .quadrature. 4.2 (t, 1H), 4.1 (q, 3H), 3.9 (m,
1H), 3.7 (m, 2H), 3.6 (m, 1H), 3.4 (dd, 1H), 3.3 (dd, 1H), 3.1 (m,
1H), 2.3 (t, 2H), 1.3-1.7 (m, 8H), 1.2 (t, 2H).
Step 7: ethyl
7-{(4S)-2-oxo-4-[(1E)-3-oxo-4-phenylbut-1-enyl]-1,3-thiazolidin-3-yl}hept-
anoate (3-7):
[0332] To a solution of 3-6 (0.56 g, 2.0 mmol) in 10 mL
CH.sub.2Cl.sub.2 was added Dess Martin periodinane (0.98 g, 2.3
mmol) in portions and the resulting solution was stirred for 2
hours. The solution was concentrated in vacuo, to which toluene was
added and concentrated thrice to remove acetic acid. The
concentrate was then filtered through celite with CH.sub.2Cl.sub.2
and concentrated in vacuo. The crude product was then diluted in 5
mL of THF and added to a solution of the Wittig reagent dimethyl
2-oxo-3-phenylpropylphosphonate (0.75 g, 3.1 mmol) and 60% sodium
hydride (0.12 g, 2.9 mmol) in 5 mL of THF at 0.degree. C. which was
premixed for half an hour. The reaction mixture was stirred for 15
minutes at the initial temperature and was allowed to warm up to
room temperature for one hour and was stored at 4.degree. C.
overnight. The reaction was then quenched with saturated aqueous
ammonium chloride solution and was extracted with ethyl acetate.
The organic phases were then combined, sequentially washed with
H.sub.2O, brine and dried over Na.sub.2SO.sub.4. After filtration
and concentration in vacuo, the compound was purified by flash
chromatography using 50% ethyl acetate/hexanes to yield 400 mg of
3-7 as a colorless oil. .sup.1H NMR (400 MHz, CDCl.sub.3): .delta.
7.40-7.21 (m, 5H), 6.75 (dd, 1H), 6.31 (d, 1H), 4.14 (q, 2H), 3.89
(s, 2H), 3.57-3.45 (m, 3H), 3.01 (dd, 1H), 2.75 (m, 1H), 2.31 (t,
2H), 1.64-1.22 (m, 8H), 1.28 (t, 3H); MS (+ESI): m/z 404.2
(M+1).sup.+.
Step 8: ethyl
7-{(4S)-4-[(1E)-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazolidin-3-yl}-
heptanoate (3-8):
[0333] To a solution of 3-7 (0.4 g, 1.0 mmol) in 12 mL 5:1
MeOH:acetic acid was added sodium cyanoborohydride (100 mg, 1.4
mmol) and the resulting solution was stirred overnight at room
temperature. The solution was quenched with water and was
concentrated in vacuo. The concentrate was extracted with ethyl
acetate and washed with 2M Na.sub.2CO.sub.3 and then brine, after
which it was dried over Na.sub.2SO.sub.4, filtered and concentrated
in vacuo. The compound was purified by flash chromatography using
60% ethyl acetate/hexanes to yield 400 mg of 3-8 as a colorless
oil. Data shown is for the major diastereomer. .sup.1H NMR (400
MHz, CDCl.sub.3): .delta. 7.35-7.21 (m, 5H), 5.84 (dd, 1H), 5.66
(dd, 1H), 4.46 (q, 1H), 4.23 (q, 1H), 4.14 (q, 2H), 3.68-3.37 (m,
2H), 2.97 (dd, 1H), 2.88 (m, 2H), 2.78 (m, 1H), 2.30 (t, 2H),
1.64-1.30 (m, 8H), 1.27 (t, 3H); MS (+ESI): m/z 406.2
(M+t).sup.+.
Step 9:
7-{(4S)-4-[(1E)-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazoli-
din-3-yl}heptanoic acid (3-9):
[0334] To a solution of 3-8 (45 mg, 0.11 mmol) in 5.5 mL 2:2:1
THF:MeOH:water, at 0.degree. C., was added lithium hydroxide (170
.mu.L of a 2M solution in water) and the resulting solution was
allowed to warm up to room temperature and stirred overnight. To
the solution was added a 1M aqueous solution of HCl (1 mL) and the
solution was extracted with ethyl acetate. The organic phases were
then combined, washed with brine, dried over MgSO.sub.4, filtered
and concentrated in vacuo. The compound was purified by flash
chromatography using 50-100% ethyl acetate/hexanes to yield 37 mg
of 3-9 as a white solid. .sup.1H NMR (400 MHz, CD.sub.3OD): .delta.
7.30-7.18 (m, 5H), 5.81 (dd, 1H), 5.53 (dd, 1H), 4.39 (q, 1H), 4.33
(q, 1H), 3.45 (dd, 1H), 3.33 (m, 1H), 2.97 (m, 2H), 2.77 (dd, 1H),
2.67 (m, 1H), 2.30 (t, 2H), 1.65-1.21 (m, 8H); MS (+ESI): m/z 378.2
(M+1).sup.+.
EXAMPLE 4
(4S)-4-[(1E)-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5-yl)hexyl-
]-1,3-thiazolidin-2-one (4-5)
Step 1:
7-{(4S)-2-oxo-4-[(tetrahydro-2H-pyran-2-yloxy)methyl]-1,3-thiazo-
lidin-3-yl}heptanenitrile (4-1):
[0335] To a solution of 3-4 (0.73 g, 3.4 mmol) in 10 mL DMF was
added 60% sodium hydride (140 mg, 3.5 mmol) and the resulting
solution was stirred for 1 hour at 50.degree. C. whereupon
7-bromoheptanonitrile (1.1 mL, 6.8 mmol) and tetrabutylammonium
iodide (50 mg) were added. The solution was stirred at 50.degree.
C. overnight afterwhich it was cooled to room temperature, slowly
poured into saturated aqueous ammonium chloride solution and was
extracted with ether. The organic phases were then combined and
sequentially washed with H.sub.2O, brine and dried over
Na.sub.2SO.sub.4, filtered and concentrated in vacuo. The compound
was purified by flash chromatography using 40-50% ethyl
acetate/hexanes to yield 970 mg of 4-1 as a colorless oil. .sup.1H
NMR (400 MHz, CDCl.sub.3): .delta. 4.63 (m, 1H), 4.04-3.68 (m, 3H),
3.68-3.58 (m, 1H), 3.55 (m, 2H), 3.42 (dd, 1H), 3.22-3.04 (m, 2H),
2.36(t, 2H), 1.86-1.44 (m, 12H), 1.38-1.30(m, 2H); MS (+ESI): m/z
327.2 (M+1).sup.+.
Step 2:
7-[(4S)-4-(hydroxymethyl)-2-oxo-1,3-thiazolidin-3-yl]heptanenitr-
ile (4-2):
[0336] To a solution of 4-1 (0.97 g, 3.0 mmol) in 10 mL EtOH was
added p-toluene sulfonic acid (50 mg) and the resulting solution
was stirred overnight at room temperature. Triethylamine (0.1 mL)
was added and the solution was concentrated in vacuo. The compound
was purified by flash chromatography using 50-80% EtOAc/hexanes to
yield 0.65 g of 4-2 as a colorless oil. .sup.1H NMR (400 MHz,
CDCl.sub.3): .delta. 3.92-3.73 (m, 3H), 3.68-3.60 (m, 1H), 3.42
(dd, 1H), 3.28 (dd, 1H), 3.10 (m, 1H), 2.37(t, 2H), 1.71-1.46 (m,
6H), 1.39-1.33(m, 2H); MS (+ESI): m/z 243.1 (M+1).sup.+.
Step 3:
7-{(4S)-2-oxo-4-[(1E)-3-oxo-4-phenylbut-1-enyl]-1,3-thiazolidin--
3-yl}heptanenitrile (4-3):
[0337] To a solution of 4-2 (0.65 g, 2.7 mmol) in 15 mL
CH.sub.2Cl.sub.2 was added Dess Martin periodinane (1.4 g, 3.2
mmol) portion wise and the resulting solution was stirred for 2
hours. The solution was concentrated in vacuo, to which toluene was
added and concentrated thrice to remove acetic acid. The
concentrate was then filtered through celite with CH.sub.2Cl.sub.2
and concentrated in vacuo. The crude product was then diluted in 7
mL of THF and added to a solution of the Wittig reagent dimethyl
2-oxo-3-phenylpropylphosphonate (1.3 g, 5.3 mmol) and 60% sodium
hydride (0.2 g, 5.1 mmol) in 7 mL of THF at 0.degree. C. which had
been premixed 30 minutes. The reaction mixture was stirred for 15
minutes at the initial temperature and was allowed to warm up to
room temperature for 1 hour. The solution was stored at 4.degree.
C. overnight, quenched with saturated aqueous ammonium chloride
solution and was extracted with ethyl acetate. The organic phases
were then combined, and sequentially washed with H.sub.2O, brine
and dried over Na.sub.2SO.sub.4, filtered and concentrated in
vacuo. The compound was purified by flash chromatography using 40%
ethyl acetate/hexanes to yield 350 mg of 4-3 as a colorless oil.
.sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 7.37-7.20 (m, 5H), 6.74
(dd, 1H), 6.31 (d, 1H), 4.34 (q, 1H), 3.88 (s, 2H), 3.54-3.44 (m,
2H), 3.01 (dd, 1H), 2.77 (m, 1H), 2.33(t, 2H), 1.67-1.60 (m, 2H),
1.47-1.30 (m, 4H), 1.28-1.23(m, 2H); MS (+ESI): m/z 356.9
(M+1).sup.+.
Step 4:
7-{(4S)-4-[(1E)-3-hydroxy-4-phenylbut-1-enyl]-2-oxo-1,3-thiazoli-
din-3-yl}heptanenitrile (4-4):
[0338] To a solution of 4-3 (0.15 g, 0.4 mmol) in 8 mL
CH.sub.2Cl.sub.2 was added 1M (R)-CBS in toluene (0.45 mL, 0.45
mmol) and cooled to -40.degree. C. to which a solution of catechol
borane (0.13 mL, 1.2 mmol) in CH.sub.2Cl.sub.2 (1 mL) was added
dropwise. The solution was stirred at -40.degree. C. for one hour
and allowed to warm up to -20.degree. C. during the following two
hours. The reaction mixture was quenched at -20.degree. C. with 1 N
HCl and was stirred for 4 hours at room temperature. The phases
were separated and the organic phase was sequentially washed with
1N HCl, H.sub.2O, 1 N NaOH, brine and dried over Na.sub.2SO.sub.4,
filtered and concentrated in vacuo. The compound was purified by
flash chromatography using 40-50% ethyl acetate/hexanes to yield
125 mg of 4-4 as a colorless oil. .sup.1H NMR (400 MHz,
CDCl.sub.3): .delta. 7.37-7.21 (m, 5H), 5.84 (dd, 1H), 5.65 (dd,
1H), 4.46 (q, 1H), 4.22 (q, 1H), 3.86-3.35 (m, 2H), 2.97 (dd, 1H),
2.88 (m, 2H), 2.80 (m, 1H), 2.36 (t, 2H), 1.70-1.27 (m, 8H); MS
(+ESI): m/z 359.0 (M+1).sup.+.
Step 5:
(4S)-4-[(1E)-3-hydroxy-4-phenylbut-1-enyl]-3-[6-(1H-tetraazol-5--
yl)hexyl]-1,3-thiazolidin-2-one (4-5):
[0339] To a solution of 4-4 (70 mg, 0.2 mmol) in 0.2 mL toluene was
added tributyltin azide (0.27 mL, 1.0 mmol) and the resulting
solution was stirred at reflux for 4 hours. Ethyl acetate (100 mL)
was added and the solution was quenched with 5% aqueous KF (30 mL)
and 1N HCl (30 mL). The layers were separated and the organic layer
was washed with brine, dried over Na.sub.2SO.sub.4, filtered and
concentrated in vacuo. The compound was purified by flash
chromatography using 0-5% MeOH/CH.sub.2Cl.sub.2 to yield 50 mg of
4-5 as a colorless oil. .sup.1H NMR (400 MHz, CD.sub.3OD): .delta.
7.29-7.17 (m, 5H), 5.81 (dd, 1H), 5.53 (dd, 1H), 4.38 (q, 1H), 4.33
(q, 1H), 3.45 (dd, 1H), 3.33 (m, 1H), 2.97 (m, 4H), 2.78 (m, 1H),
2.68 (m, 1H), 1.83-1.21 (m, 8H); MS (-ESI): m/z 400.2
(M-1).sup.-.
I. Effects of an EP4 Agonist on Intraocular Pressure (IOP) in
Rabbits and Monkeys.
Animals
[0340] Drug-naive, male Dutch Belted rabbits and female cynomolgus
monkeys are used in this study. Animal care and treatment in this
investigation are in compliance with guidelines by the National
Institute of Health (NIH) and the Association for Research in
Vision and Ophthalmology (ARVO) resolution in the use of animals
for research. All experimental procedures str approved by the
Institutional Animal Care and Use Committee of Merck and
Company.
Drug Preparation and Administration
[0341] Drug concentrations are expressed in terms of the active
ingredient (base). The compounds of this invention are dissolved in
physiological saline at 0.01, 0.001, 0.0001% for rabbit study and
0.05, 0.005% for monkey studies. Drug or vehicle aliquots (25 ul)
are administered topically unilaterally or bilaterally. In
unilateral applications, the contralateral eyes receive an equal
volume of saline. Proparacaine (0.5%) is applied to the cornea
prior to tonometry to minimize discomfort. Intraocular pressure
(IOP) is recorded using a pneumatic tonometer (Alcon Applanation
Pneumatonograph) or equivalent.
Statistical Analysis
[0342] The results are expressed as the changes in IOP from the
basal level measured just prior to administration of drug or
vehicle and represent the mean, plus or minus standard deviation.
Statistical comparisons are made using the Student's t-test for
non-paired data between responses of drug-treated and
vehicle-treated animals and for paired data between ipsilateral and
contralateral eyes at comparable time intervals. The significance
of the date is also determined as the difference from the "t-0"
value using Dunnett's "t" test. Asterisks represent a significance
level of p<0.05.
A. Intraocular Pressure Measurement in Rabbits
[0343] Male Dutch Belted rabbits weighing 2.5-4.0 kg are maintained
on a 12-hour light/dark cycle and rabbit chow. All experiments are
performed at the same time of day to minimize variability related
to diurnal rhythm. IOP is measured before treatment then the
compounds of this invention or vehicle are instilled (one drop of
25 ul) into one or both eyes and IOP is measured at 30, 60, 120,
180, 240, 300, and 360 minutes after instillation. In some cases,
equal number of animals treated bilaterally with vehicle only are
evaluated and compared to drug treated animals as parallel
controls.
B. Intraocular Pressure Measurements in Monkeys.
[0344] Unilateral ocular hypertension of the right eye is induced
in female cynomolgus monkeys weighing between 2 and 3 kg by
photocoagulation of the trabecular meshwork with an argon laser
system (Coherent NOVUS 2000, Palo Alto, USA) using the method of
Lee at al. (1985). The prolonged increase in intraocular pressure
(IOP) results in changes to the optic nerve head that are similar
to those found in glaucoma patients.
[0345] For IOP measurements, the monkeys are kept in a sitting
position in restraint chairs for the duration of the experiment.
Animals are lightly anesthetized by the intramuscular injection of
ketamine hydrochloride (3-5 mg/kg) approximately five minutes
before each IOP measurement and one drop of 0.5% proparacaine was
instilled prior to recording IOP. IOP is measured using a pneumatic
tonometer (Alcon Applanation Tonometer) or a Digilab
pneumatonometer (Bio-Rad Ophthalmic Division, Cambridge, Mass.,
USA).
[0346] IOP is measured before treatment and generally at 30, 60,
124, 180, 300, and 360 minutes after treatment. Baseline values are
also obtained at these time points generally two or three days
prior to treatment. Treatment consists of instilling one drop of 25
ul of the compounds of this invention (0.05 and 0.005%) or vehicle
(saline). At least one-week washout period is employed before
testing on the same animal. The normotensive (contralateral to the
hypertensive) eye is treated in an exactly similar manner to the
hypertensive eye. IOP measurements for both eyes are compared to
the corresponding baseline values at the same time point. Results
are expressed as mean plus-or-minus standard deviation in mm Hg.
The activity range of the compounds of this invention for ocular
use is between 0.01 and 100,000 nM
II. Radioligand Binding Assays:
[0347] The assays used to test these compounds were performed
essentially as described in: Abramovitz M, Adam M, Boie Y, Carriere
M, Denis D, Godbout C, Lamontagne S, Rochette C, Sawyer N, Tremblay
N M, Belley M, Gallant M, Dufresne C, Gareau Y, Ruel R, Juteau H,
Labelle M, Ouimet N, Metters K M. The utilization of recombinant
prostanoid receptors to determine the affinities and selectivities
of prostaglandins and related analogs. Biochim Biophys Acta 2000
Jan 17;1483(2):285-293 and discussed below:
Stable Expression of Prostanoid Receptors in the Human Embryonic
Kidney (HEK) 293(EBNA) Cell Line
[0348] Prostanoid receptor (PG) cDNAs corresponding to full length
coding sequences were subcloned into the appropriate sites of the
mammalian expression vector pCEP4 (Invitrogen) pCEP4PG plasmid DNA
was prepared using the Qiagen plasmid preparation kit (QIAGEN) and
transfected into HEK 293(EBNA) cells using LipofectAMINE@
(GIBCO-BRL) according to the manufacturers' instructions. HEK
293(EBNA) cells expressing the cDNA together with the hygromycin
resistance gene were selected in Dulbecco's Modified Eagle Medium
(DMEM) supplemented with 10 % heat inactivated fetal bovine serum,
1 mM sodium pyruvate, 100 U/ml Penicillin-G, 100 .mu.g/ml
Streptomycin sulphate, 250 .mu.g/ml active GENETICIN.TM. (G418)
(all from Life Technologies, Inc./BRL) and 200 .mu.g/ml hygromycin
(Calbiochem). Individual colonies were isolated after 2-3 weeks of
growth under selection using the cloning ring method and
subsequently expanded into clonal cell lines. Expression of the
receptor cDNA was assessed by receptor binding assays.
[0349] HEK 293(EBNA) cells were grown in supplemented DMEM complete
medium at 37.degree. C. in a humidified atmosphere of 6% CO.sub.2
in air, then harvested and membranes prepared by differential
centrifugation (1000.times.g for 10 min, then 160,000.times.g for
30 min, all at 4.degree. C.) following lysis of the cells by
nitrogen cavitation at 800 psi for 30 min on ice in the presence of
protease inhibitors (2 mM phenylmethylsulfonylfluoride, 10 .mu.M
E-64, 100 .mu.M leupeptin and 0.05 mg/ml pepstatin). The
160,000.times.g pellets were resuspended in 10 mM HEPES/KOH (pH
7.4) containing 1 mM EDTA at approximately 5-10 mg/ml protein by
Dounce homogenisation (Dounce A; 10 strokes), frozen in liquid
nitrogen and stored at -80.degree. C.
Prostanoid Receptor Binding Assays
[0350] Prostanoid receptor binding assays were performed in a final
incubation volume of 0.2 ml in 10 mM MES/KOH (pH 6.0) (EP subtypes,
FP and TP) or 10 mM HEPES/KOH (pH 7.4) (DP and IP), containing 1 mM
EDTA, 10 mM MgCl.sub.2 (EP subtypes) or 10 mM MnCl.sub.2 (DP, FP,
IP and TP) and radioligand [0.5-1.0 nM [.sup.3H]PGE.sub.2 (181
Ci/mmol) for EP subtypes, 0.7 nM [.sup.3H]PGD.sub.2 (115 Ci/mmol)
for DP, 0.95 nM [.sup.3H]PGF.sub.2.alpha. (170 Ci/mmol) for FP, 5
nM [.sup.3H]iloprost (16 Ci/mmol) for IP and 1.8 nM [.sup.3H]SQ
29548 (46 Ci/mmol) for TP]. EP.sub.3 assays also contained 100
.mu.M GTP.gamma.S. The reaction was initiated by addition of
membrane protein (approximately 30 .mu.g for EP.sub.1, 20 .mu.g for
EP.sub.2, 2 .mu.g for EP.sub.3, 10 .mu.g for EP.sub.4, 60 .mu.g for
FP, 30 .mu.g for DP, 10 .mu.g for IP and 10 .mu.g for TP) from the
160,000.times.g fraction. Ligands were added in dimethylsulfoxide
(Me.sub.2SO) which was kept constant at 1% (v/v) in all
incubations. Non-specific binding was determined in the presence of
1 .mu.M of the corresponding non-radioactive prostanoid.
Incubations were conducted for 60 min (EP subtypes, FP and IP) or
30 min (DP and TP) at 30.degree. C. (EP subtypes, DP, FP and TP) or
room temperature (IP) and terminated by rapid filtration through a
96-well Unifilter GF/C (Canberra Packard) prewetted in assay
incubation buffer without EDTA (at 4.degree. C.) and using a Tomtec
Mach III 96-well semi-automated cell harvester. The filters were
washed with 3-4 ml of the same buffer, dried for 90 min at
55.degree. C. and the residual radioactivity bound to the
individual filters determined by scintillation counting with
addition of 50 .mu.L of Ultima Gold F (Canberra Packard) using a
1450 MicroBeta (Wallac). Specific binding was calculated by
subtracting non-specific binding from total binding. Specific
binding represented 90-95% of the total binding and was linear with
respect to the concentrations of radioligand and protein used.
Total binding represented 5-10% of the radioligand added to the
incubation media.
[0351] The activity range of the compounds of this invention for
bone use is between 0.01 and 100,000 nM.
Bone Resorption Assays:
1. Animal Procedures:
[0352] For mRNA localization experiments, 5-week old Sprague-Dawley
rats (Charles River) are euthanized by CO.sub.2, their tibiae and
calvariae are excised, cleaned of soft tissues and frozen
immediately in liquid nitrogen. For EP.sub.4 regulation
experiments, 6-week old rats are given a single injection of either
vehicle (7% ethanol in sterile water) or an anabolic dose of
PGE.sub.2 (Cayman Chemical, Ann Arbor, Mich.), 3-6 mg/kg in the
same vehicle) intraperitoneally. Animals are euthanized at several
time points post-injection and their tibiae and calvariae, as well
as samples from lung and kidney tissues are frozen in liquid
nitrogen.
2. Cell Cultures
[0353] RP-1 periosteal cells are spontaneously immortalized from
primary cultures of periosteal cells from tibae of 4-week old
Sprague-Dawley rats and are cultured in DMEM (BRL, Gaithersburg,
Md.) with 10% fetal bovine serum (JRH Biosciences, Lenexa, Kans.).
These cells do not express osteoblastic phenotypic markers in early
culture, but upon confluence, express type I collagen, alkaline
phosphatase and osteocalcin and produce mineralized extracellular
matrix.
[0354] RCT-1 and RCT-3 are clonal cell lines immortalized by SV-40
large T antigen from cells released from fetal rat calvair by a
cmbination collagenase/hyaluronidase digestion. RCT-1 cells,
derived from cells released during the first 10 minutes of
digestion (fraction I), are cultured in RPMI 1640 medium (BRL) with
10% fetal bovine serum and 0.4 mg/ml G418 (BRL). These cells
differentiate and express osteoblastic features upon retinoic acid
treatment. RCT-3 cells, immortalized from osteoblast-enriched
fraction III cells, are cultured in F-12 medium (BRL) with 5% Fetal
bovine serum and 0.4 mg/ml G418. TRAB-11 cells are also
immortalized by SV40 large T antigen from adult rat tibia and are
cultured in RPMI 1640 medium with 10% FBS and 0.4 mg/ml G418. ROS
17/2.8 rat osteosarcoma cells are cultured in F-12 containing 5%
FBS. Osteoblast-enriched (fraction III) primary fetal rat calvaria
cells are obtained by collagenase/hyaluronidase digestion of
calvariae of 19 day-old rat fetuses. See Rodan et al., Growth
stimulation of rat calvaria osteoblastic cells by acidic FGF,
Endocrinology, 121, 1919-1923 (1987), which is incorporated by
reference herein in its entirety. Cells are released during 30-50
minutes digestion (fraction III) and are cultured in F-12 medium
containing 5% FBS.
[0355] P815 (mouse mastocytoma) cells, cultured in Eagles MEM with
10% FBS, and NRK (normal rat kidney fibroblasts) cells, cultured in
DMEM with 10% FBS, are used as positive and negative controls for
the expression of EP.sub.4, respectively. See Abramovitz et al.,
Human prostanoid receptors: cloning and characterization. In:
Samulesson B. et al. ed) Advances in prostaglandin, Thrombosznes
and leukotriene research, vol. 23, pp. 499-504 (1995) and de Larco
et al., Epithelioid and fibroblastic rat kidney cell clones: EGF
receptors and the effect of mouse sarcoma virus transformation,
Cell Physiol., 94, 335-342 (1978), which are both incorporated by
reference herein in their entirety.
3. Northern Blot Analysis:
[0356] Total RNA is extracted from the tibial metaphysis or
diaphysis and calvaria using a guanidinium
isothiocyanate-phenol-chloroform method after pulverizing frozen
bone samples by a tissue homogenizer. See P. Chomczynski et al.,
Single-step method ofRNA isolation by acid guanidium
thiocyanate-phenol-chloroform extraction., Analyt Biochem, 162,
156-159 (1987), which is incorporated by reference herein in its
entirety. RNA samples (20 mg) are separated on 0.9%
agarose/formaldehyde gels and transferred onto nylon membranes
(Boehringer Mannheim, Germany). Membranes are prehybridized in
Hybrisol I (Oncor, Gaithersburg, Md.) and 0.5 mg/ml sonicated
salmon sperm DNA (Boehringer) at 42.degree. C. for 3 hours and are
hybridized at 42.degree. C. with rat EP.sub.2 and mouse EP.sub.4
cDNA probes labeled with [.sup.32P]-dCTP (Amersham,
Buckinghamshire, UK) by random priming using the rediprime kit
(Amersham). After hybridization, membranes are washed 4 times in
2.times.SSC+0.1% SDS at room temperature for a total of 1 hour and
once with 0.2.times.SSC+0.1% SDS at 55.degree. C. for 1 hour and
then exposed to Kodak XAR 2 film at -70.degree. C. using
intensifying screens. After developing the films, bound probes are
removed twice with 0.1% SDS at 80.degree. C. and membranes are
hybridized with a human GAPDH (Glyceraldehyde 3-Phosphate
Dehydrogenase) cDNA probe (purchased from Clontech, Palo Alto,
Calif.) for loading control.
4. In-Situ Hybridization:
[0357] Frozen tibiae are sectioned coronally at 7 mm thickness and
sections are mounted on charged slides (Probe On Plus, Fisher
Scientific, Springfield, N.J.) and are kept at -70.degree. C. until
hybridization. cRNA probes are labeled with .sup.35S-UTPgS (ICN,
Costa Mesa, Calif.) using a Riboprobe II kit (Promega Madison,
Wis.). Hybridization is performed overnight at 50.degree. C. See M.
Weinreb et al., Different pattern of alkaline phosphatase,
osteopontin and osteocalcin expression in developing rat bone
visualized by in-situ hybridization, J. Bone Miner Res., 5, 831-842
(1990) and D. Shinar et al., Expression of alphav and beta3
integrin subunits in rat osteoclasts in situ, J. Bone Miner. Res.,
8, 403-414 (1993), which are both incorporated by reference herein
in their entirety. Following hybridization and washing, sections
are dipped in Ilford K5 emulsion diluted 2:1 with 6% glycerol in
water at 42.degree. C. and exposed in darkness at 4.degree. C. for
12-14 days. Slides are developed in Kodak D-19 diluted 1:1 with
water at 15.degree., fixed, washed in distilled water and mounted
with glycerol-gelatin (Sigma) after hematoxylin staining. Stained
sections are viewed under the microscope (Olympus, Hamburg,
Germany), using either bright-field or dark-field optics.
5. Expression of EP.sub.4 in Osteoblastic Cell Lines and in Bone
Tissue.
[0358] The expression of EP.sub.4 and EP.sub.2 mRNA is examined in
various bone derived cells including osteoblast-enriched primary
rat calvaria cells, immortalized osteoblastic cell lines from fetal
rat calvaria or from adult rat tibia and an osteoblastic
osteosarcoma cell line. Most of the osteoblastic cells and cell
lines show significant amounts of 3.8 kb EP.sub.4 mRNA, except for
the rat osteosarcoma cell line ROS 17/2.8. Consistent with this
finding, in ROS 17/2.8 cells PGE.sub.2 has no effect on
intracellular cAMP, which is markedly induced in RCT-3 and TRAB-11
cells. Treatment of RCT-1 cells with retinoic acid, which promotes
their differentiation, reduces the levels of EP.sub.4 mRNA. NRK
fibroblasts do not express EP.sub.4 mRNA, while P815 mastocytoma
cells, used as positive controls, express large amounts of EP.sub.4
mRNA. In contrast to EP.sub.4 mRNA, none of the osteoblastic cells
and cell lines express detectable amounts of EP.sub.2 mRA in total
RNA samples. Expression of EP.sub.4 mRNA in osteoblastic cells,
EP.sub.4 is also expressed in total RNA isolated from tibiae and
calvariae of 5-week-old rats. In contrast, no EP.sub.2 mRNA is
found in RNA from tibial shafts.
6. PGE.sub.2 Induces the Expression of EP.sub.4 mRNA in RP-1
Periosteal Cells and in Adult Rat Tibiae
[0359] PGE.sub.2 enhances its own production via upregulation of
cyclooxygenase 2 expression in osteoblasts and in bone tissue thus
autoamplifying its own effects. PGE.sub.2 also increases the levels
of EP.sub.4 mRNA. RP-1 cells are immortalized from a primary
culture of adult rat tibia periosteum is examined. These cells
express osteoblast phenotypic markers upon confluence and form
mineralized bone matrix when implanted in nude mice. Similar to the
other osteoblastic cells examined, RP-1 periosteal cells express a
3.8 kb EP.sub.4 transcript. Treatment with PGE.sub.2 (10.sup.-6 M)
rapidly increases EP.sub.4 mRNA levels peaking at 2 hours after
treatment. PGE.sub.2 has no effect on EP.sub.4 mRNA levels in the
more differentiated RCT-3 cells pointing to cell-type specific
regulation of EP.sub.4 expression by PGE.sub.2. EP.sub.2 mRNA is
not expressed in RP-1 cells before or after treatment with
PGE.sub.2.
[0360] To examine if PGE.sub.2 regulates EP.sub.4 mRNA levels in
vivo in bone tissue, five-week-old male rats are injected with
PGE.sub.2 (3-6 mg/Kg). Systemic administration of PGE.sub.2 rapidly
increased EP.sub.4 mRNA levels in the tibial diaphysis peaking at 2
h after injection. A similar effect of PGE.sub.2 on EP.sub.4 mRNA
is observed in the tibial metaphysis and in calvaria. PGE.sub.2
induces EP.sub.4 mRNA levels in vitro in osteogenic periosteal
cells and in vivo in bone tissue in a cell type-specific and
tissue-specific manner. PGE.sub.2 does not induce EP.sub.2 mRNA in
RP-1 cells nor in bone tissue.
7. Localization of EP4 mRNA Expression in Bone Tissue
[0361] In situ hybridization is used in order to localize cells
expressing EP.sub.4 in bone. In control experiment
(vehicle-injected) rats, low expression of EP.sub.4 is detected in
bone marrow cells. Administration of a single anabolic dose of
PGE.sub.2 increased the expression of EP.sub.4 in bone marrow
cells. The distribution of silver grains over the bone marrow is
not uniform and occurs in clumps or patches in many areas of the
metaphysis. Within the tibial metaphysis, EP.sub.4 expression is
restricted to the secondary spongiosa area and is not seen in the
primary spongiosa. Hybridization of similar sections with a sense
probe (negative control) does not show any signal.
[0362] EP.sub.4 is expressed in osteoblastic cells in vitro and in
bone marrow cells in vivo, and is upregulated by its ligand,
PGE.sub.2.
8. Agonists of the Present Invention
[0363] Using standard methods for measuring agonist activity, the
following compounds are evaluated in cell cultures and in EP.sub.4
receptor cell-free systems to determine the agonist activity of the
compounds in terms of their EC.sub.50 value.
* * * * *