Substituted benzazoles and methods of their use as inhibitors of raf kinase

1. A method of inhibiting Raf kinase activity in a human or animal subject suffering from a Ras/mitogen-activated protein kinase signal pathway-mediated cancer disorder selected from the group consisting of melanoma, breast cancer, prostate cancer, lung cancer, pancreatic cancer, thyroid cancer, bladder cancer, colon cancer, liver cancer, myeloid leukemia, and villous colon adenoma, comprising administering to the human or animal subject a composition comprising an amount of a compound of the formula (II) effective to inhibit Raf kinase activity in the human or animal subject:

wherein Y is O;

A 1 is substituted monocyclic carbocyclic aryl;

A 2 is pyridyl;

R 1 is taken together with R 2 to form a substituted or unsubstituted imidazolyl group, or a substituted or unsubstituted benzimidazolyl group, wherein the dashed line represents a single or double bond;

R 3 is hydrogen; and

R 4 is C 1-6 alkyl;

or a pharmaceutically acceptable salt thereof.

2. The method of claim 1 which further comprises administering to the human or animal subject at least one additional agent for the treatment of cancer selected from irinotecan, topotecan, gemcitabine, 5-fluorouracil, leucovorin, carboplatin, cisplatin, taxanes, tezacitabine, cyclophosphamide, vinca alkaloids, imatinib, anthracyclines, rituximab and trastuzumab.

3. A method of inhibiting Raf kinase activity in a human or animal subject suffering from a Ras/mitogen-activated protein kinase signal pathway-mediated hormone dependent cancer disorder selected from the group consisting of breast cancer and prostate cancer, comprising administering to the human or animal subject a composition comprising an amount of a compound of the formula (II) effective to inhibit Raf kinase activity in the human or animal subject:

wherein Y is O;

A 1 is substituted monocyclic carbocyclic aryl;

A 2 is pyridyl;

R 1 is taken together with R 2 to form a substituted or unsubstituted imidazolyl group, or a substituted or unsubstituted benzimidazolyl group, wherein the dashed line represents a single or double bond;

R 3 is hydrogen; and

R 4 is C 1-6 alkyl;

or a pharmaceutically acceptable salt thereof.

4. The method of claim 3 which further comprises administering to the human or animal subject at least one additional agent for the treatment of cancer selected from irinotecan, topotecan, gemcitabine, 5-fluorouracil, leucovorin, carboplatin, cisplatin, taxanes, tezacitabine, cyclophosphamide, vinca alkaloids, imatinib, anthracyclines, rituximab and trastuzumab.

5. A method of inhibiting Raf kinase activity in a human or animal subject suffering from a Ras/mitogen-activated protein kinase signal pathway-mediated hematological cancer disorder, comprising administering to the human or animal subject a composition comprising an amount of a compound of the formula (II) effective to inhibit Raf kinase activity in the human or animal subject:

wherein Y is O;

A 1 is substituted monocyclic carbocyclic aryl;

A 2 is pyridyl;

R 1 is taken together with R 2 to form a substituted or unsubstituted imidazolyl group, or a substituted or unsubstituted benzimidazolyl group, wherein the dashed line represents a single or double bond;

R 3 is hydrogen; and

R 4 is C 1-6 alkyl;

or a pharmaceutically acceptable salt thereof.

6. The method of claim 5 which further comprises administering to the human or animal subject at least one additional agent for the treatment of cancer selected from irinotecan, topotecan, gemcitabine, 5-fluorouracil, leucovorin, carboplatin, cisplatin, taxanes, tezacitabine, cyclophosphamide, vinca alkaloids, imatinib, anthracyclines, rituximab and trastuzumab.

7. The method of any one of claim 1 , 2 , 3 , 4 , 5 , or 6 , wherein R 4 in formula (II) is methyl.

8. A method of any one of claim 1 , 2 , 3 , 4 , 5 , or 6 , wherein A 1 in formula (II) is substituted phenyl.

9. The method of claim 8 , wherein A 1 in formula (II) is 4-bromophenyl.

10. The method of claim 8 , wherein A 1 in formula (II) is trifluoromethylchlorophenyl.

11. The method of any one of claim 1 , 2 , 3 , 4 , 5 , or 6 , wherein A 2 in formula (II) is

12. The method of claim 1 , wherein the imidazolyl group or benzimidazolyl group is substituted with a halo C 1-6 alkyl group.

13. The method of claim 1 , wherein the imidazolyl group or benzimidazolyl group is substituted with a trifluoromethyl group.

14. The method of claim 1 , wherein the cancer is melanoma.

15. The method of claim 1 , wherein the cancer is a carcinoma of the lungs, pancreas, thyroid, bladder or colon.

16. The method of claim 1 , wherein the cancer is myeloid leukemia.

17. The method of claim 1 , wherein the cancer is villous colon adenoma.

18. The method of claim 5 wherein the hematological cancer disorder is chronic myelogenous leukemia.

19. The method of any one of claim 1 , 2 , 3 , 4 , 5 , or 6 , wherein A 1 in formula (II) is substituted phenyl.

20. A method of any one of claim 1 , 2 , 3 , 4 , 5 , or 6 , wherein the variables in formula (II) are as follows:

A 1 is a substituted phenyl group;

A 2 is pyridyl;

R 1 is taken together with R 2 to form a substituted or unsubstituted imidazolyl group, or a substituted or unsubstituted benzimidazolyl group; and

R 4 is C 1-6 alkyl;

or a pharmaceutically acceptable salt thereof.

21. The method of claim 20 , wherein A 1 is substituted phenyl.

22. A method of any one of claim 1 , 2 , 3 , 4 , 5 , or 6 , wherein the variables in formula (II) are as follows:

A 1 is a substituted phenyl, thiophenyl, or indenyl;

A 2 is

R 1 is taken together with R 2 to form substituted or unsubstituted imidazolyl group, or a substituted or unsubstituted benzimidazolyl; and

R 3 is hydrogen; and

R 4 is C 1-6 alkyl;

or a pharmaceutically acceptable salt thereof.

23. The method of claim 22 , wherein A1 is substituted phenyl.