Factor XIA inhibitors

1. A compound of the formula:

wherein

 is aryl or heteroaryl, which is optionally substituted with one to three groups independently selected from the group consisting of halo, oxo, cyano, R 6 , OR 6 , C(O)OR 6 , C 1-3 alkyl-C(O)OR 6 , NR 6 R 7 , NH 3 + , C 1-3 alkyl-NR 7 R 8 , NHC(O)R 6 , NHC(O)OR 6 , NHC(O)OC 3-6 cycloalkyl, NHC(O)O—C 1-3 alkyl-OR 7 , NHC(O)O—C 1-3 alkyl-C(O)OH, C 1-3 alkyl-NHC(O)OR 7 , NHC(O)NR 7 R 8 , NHSO 2 R 6 , C(O)NR 7 R 8 , CH 2 C(O)NR 7 R 8 and NHCONH—C 1-3 alkyl-heterocyclyl;

 is aryl or heteroaryl, which is optionally substituted with one to three groups independently selected from the group consisting of halo, cyano, oxido, oxo, cyclopropyl, R 6 , OR 6 , C(O)OR 6 , C 1-3 alkyl- C(O)OR 6 , C(O)NR 6 R 7 and NR 6 R 7 ;

W is N or N + O − ;

Y—X is —C(O)NR 6 —, —C(O)O—, —CHC(O)OR 7 —NR 6 —, —CR 6 R 7 —C(O)NR 6 —, —CHC(O)R 7 —NR 6 —, —CHC(O)OR 7 —CH 2 —, —CHC(O)NR 6 R 7 —NR 6 —, —CHCR 6 R 7 OR 8 —NR 6 —, —CHCR 6 R 7 —NR 6 R 7 —NR 6 —, —OC(O)NR 6 —, —NR 6 C(O)NR 6 - or -SO 2 NR 6 —;

Z is C 3-8 alkylene or C 3-8 alkenylene, wherein one or two of the carbon atoms in said alkylene and alkenylene may be replaced with O, NR 6 , C═O, C(O)NR 6 , NR 6 C(O), S, SO or SO 2;

R 1 is aryl, heteroaryl, C 3-6 cycloalkyl or heteroalkyl, wherein said aryl, heteroaryl, cycloalkyl and heterocyclyl groups are optionally substituted with one to four substituents independently selected from the group consisting of halo, nitro, cyano, oxo, R 6 , OR 6 , C(O)R 6 , C(O)OR 6 , NR 6 R 7 , C 1-3 alkyl-NR 6 R 7 , NHC(O)R 7 , NHC(O)OR 7 , C(NH)NR 6 R 7 , C 3-6 cycloalkyl and heteroaryl (which is optionally substituted with halo, cyano, cyclopropyl, C(O)OH, C(O)NR 6 R 7 or R 6 );

R 2 is hydrogen, cyano, halo, R 6 or OR 6 ;

R 3 is hydrogen, cyano, halo, R 6 or OR 6 ;

each R 4 is independently C 1-6 alkyl, CO 2 R 6 , COR 6 or CONR 7 R 8 , wherein said alkyl is optionally substituted with one to three halo;

R 5 is hydrogen, halo or C 1-6 alkyl;

or one of R 4 and R 5 can be taken together with the atoms between them to form a 3 to 6 membered ring;

each R 6 is independently hydrogen or C 1-6 alkyl, which is optionally substituted with one to three groups independently selected from the group consisting of halo and hydroxy;

each R 7 is independently hydrogen, C 1-6 alkyl, heteroaryl or heterocyclyl, wherein said alkyl group is optionally substituted with one to three groups independently selected from the group consisting of halo and hydroxy;

each R 8 is independently hydrogen or C 1-6 alkyl;

R a is hydrogen, hydroxy or O(C 1-6 alkyl);

n is an integer between zero and three;

or a pharmaceutically acceptable salt thereof.

2. The compound of claim 1 of the formula

wherein

 is aryl or heteroaryl, which is optionally substituted with one to three groups independently selected from the group consisting of halo, oxo, cyano, R 6 , OR 6 , C(O)OR 6 , C 1-3 alkyl-C(O)OR 6 , NR 6 R 7 , NH 3 + , C 1-3 alkyl-NR 7 R 8 , NHC(O)R 6 , NHC(O)OR 6 , NHC(O)OC 3-6 cycloalkyl, NHC(O)O—C 1-3 alkyl-OR 7 , NHC(O)O—C 1-3 alkyl-C(O)OH, C 1-3 alkyl-NHC(O)OR 7 , NHC(O)NR 7 R 8 , NHSO 2 R 6 , C(O)NR 7 R 8 , CH 2 C(O)NR 7 R 8 and NHCONH—C 1-3 alkyl-heterocyclyl;

 is aryl or heteroaryl, which is optionally substituted with one to three groups independently selected from the group consisting of halo, cyano, oxido, oxo, cyclopropyl, R 6 , OR 6 , C(O)OR 6 , C 1-3 alkyl-C(O)OR 6 , C(O)NR 6 R 7 and NR 6 R 7 ;

R 1 is aryl, heteroaryl, C 3-6 cycloalkyl or heteroalkyl, wherein said aryl, heteroaryl, cycloalkyl and heterocyclyl groups are optionally substituted with one to four substituents independently selected from the group consisting of halo, nitro, cyano, oxo, R 6 , OR 6 , C(O)R 6 , C(O)OR 6 , NR 6 R 7 , C 1-3 alkyl-NR 6 R 7 , NHC(O)R 7 , NHC(O)OR 7 , C(NH)NR 6 R 7 , C 3-6 cycloalkyl and heteroaryl (which is optionally substituted with halo, cyano, cyclopropyl, C(O)OH, C(O)NR 6 R 7 or R 6 );

R 2 is hydrogen, cyano, halo, R 6 or OR 6 ;

R 3 is hydrogen, cyano, halo, R 6 or OR 6 ;

R 4 is C 1-6 alkyl, CO 2 R 6 , COR 6 or CONR 7 R 8 , wherein said alkyl is optionally substituted with one to three halo;

R 6 is hydrogen or C 1-6 alkyl, which is optionally substituted with one to three groups independently selected from the group consisting of halo and hydroxy;

R 7 is hydrogen or C 1-6 alkyl, which is optionally substituted with one to three groups independently selected from the group consisting of halo and hydroxy;

R 8 is hydrogen or C 1-6 alkyl;

R a is hydrogen, hydroxy or O(C 1-6 alkyl);

n is an integer between zero and three;

or a pharmaceutically acceptable salt thereof.

3. The compound of claim 1 wherein

 is a selected from the group consisting of phenyl, imidazolyl, pyridinyl and pyrimidinyl, wherein said groups are optionally substituted with one to three groups independently selected from the group consisting of halo, oxido, R 6 and cyclopropyl.or a pharmaceutically acceptable salt thereof.

4. The compound of claim 1 wherein

 is phenyl, which is optionally substituted with one to three groups independently selected from the group consisting of halo, C(O)OR 6 and NHC(O)OR 6 ; or a pharmaceutically acceptable salt thereof.

5. The compound of claim 1 wherein R 1 is aryl, which optionally is substituted with one to four substituents independently selected from the group consisting of chloro, fluoro, iodo, methyl, cyclopropyl, OCF 3 , OCF 2 , CF 3 , CF 2 , and heteroaryl (which is optionally substituted with halo, cyano, cyclopropyl, C(O)OH, methyl, CF 3 or CF 2 ); or a pharmaceutically acceptable salt thereof.

6. The compound of any of claim 1 wherein R 1 is phenyl, which optionally is substituted with one to three substituents independently selected from the group consisting of halo, cyclopropyl and tetrazolyl; or a pharmaceutically acceptable salt thereof.

7. The compound of any of claim 1 wherein R a is hydrogen or hydroxy; or a pharmaceutically acceptable salt thereof.

8. The compound of claim 1 selected from:

or a pharmaceutically acceptable salt thereof.

9. A pharmaceutical composition comprising a compound of claims 1 or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier.

10. A method for inhibiting thrombus formation in blood or treating thrombus formation in blood comprising administering a composition of claim 9 to a mammal in need of thereof.

11. A method for preventing thrombus formation in blood comprising administering a composition of claim 9 to a mammal in need thereof.

12. A method of treating venous thromboembolism and pulmonary embolism in a mammal comprising administering a composition of claim 9 to a mammal in need thereof.

13. A method of treating deep vein thrombosis in a mammal comprising administering a composition of claim 9 to a mammal in need thereof.

14. A method of treating thromboembolic stroke in a human comprising administering a composition of claim 9 to a mammal in need thereof.