Compositions useful for treating disorders related to kit

1. A compound of Formula II:

or a pharmaceutically acceptable salt thereof, wherein:

Ring A is selected from monocyclic or bicyclic aryl, monocyclic or bicyclic heteroaryl, cycloalkyl and heterocyclyl;

each X and Y is independently selected from CR 1 and N;

Z is selected from C 1 -C 6 alkyl, cycloalkyl, monocyclic or bicyclic aryl, monocyclic or bicyclic aralkyl, monocyclic or bicyclic heteroaryl, monocyclic or bicyclic heterocyclyl, and monocyclic or bicyclic heterocyclylalkyl; wherein each of C 1 -C 6 alkyl, cycloalkyl, monocyclic or bicyclic aryl, monocyclic or bicyclic aralkyl, monocyclic or bicyclic heteroaryl, monocyclic or bicyclic heterocyclyl, and monocyclic or bicyclic heterocyclylalkyl is substituted with 0-5 independent occurrences of R C ;

L is selected from a bond, —(C(R 2 )(R 2 )) m —, —(C 2 -C 6 alkynylene)-, —(C 2 -C 6 alkenylene)-, —(C 1 -C 6 haloalkylene)-, —(C 1 -C 6 heteroalkylene)-, —(C 1 -C 6 hydroxyalkylene)-, —C(O)—, —O—, —S—, —S(O), —SO 2 —, —N(R 2 )—, —O—(C 1 -C 6 alkylene)-, —(C 1 -C 6 alkylene)-O—, —N(R 2 )—CO—, —CO—N(R 2 )—, —(C 1 -C 6 alkylene)-N(R 2 )—, —N(R 2 )—(C 1 -C 6 alkylene)-, —N(R 2 )—CO—(C 1 -C 6 alkylene)-, —CO—N(R 2 )—(C 1 -C 6 alkylene)-, —N(R 2 )—SO 2 —, —SO 2 —N(R 2 )—, —N(R 2 )—SO 2 —(C 1 -C 6 alkylene)-, and —SO 2 —N(R 2 )—(C 1 -C 6 alkylene)-;

each R A and R B is independently selected from C 1 -C 6 alkyl, halo, C 1 -C 6 haloalkyl, C 1 -C 6 hydroxyalkyl, C 1 -C 6 heteroalkyl, monocyclic or bicyclic aralkyl, —N(R 2 )(R 2 ), cyano, and —OR 2 ;

each R C is independently selected from C 1 -C 6 alkyl, C 1 -C 6 alkynyl, halo, C 1 -C 6 heteroalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, C 1 -C 6 hydroxyalkyl, cycloalkyl, monocyclic or bicyclic aryl, monocyclic or bicyclic aryloxy, monocyclic or bicyclic aralkyl, monocyclic or bicyclic heterocyclyl, monocyclic or bicyclic heterocyclylalkyl, nitro, cyano, —C(O)R 2 , —OC(O)R 2 , —C(O)OR 2 , —SR 2 , —S(O) 2 R 2 , —S(O) 2 —N(R 2 )(R 2 ), —(C 1 -C 6 alkylene)-S(O) 2 —N(R 2 )(R 2 ), —N(R 2 )(R 2 ), —C(O)—N(R 2 )(R 2 ), —N(R 2 )(R 2 )—C(O)R 2 , —(C 1 -C 6 alkylene)-N(R 2 )—C(O)R 2 , —NR 2 S(O) 2 R 2 , —P(O)(R 2 )(R 2 ), and —OR 2 ; wherein each of heteroalkyl, haloalkyl, haloalkoxy, alkyl, alkynyl, cycloalkyl, aryl, aryloxy, aralkyl, heterocyclyl, and heterocyclylalkyl is substituted with 0-5 occurrences of R a ; or 2 R C together with the carbon atom(s) to which they are attached form a cycloalkyl or heterocyclyl ring substituted with 0-5 occurrences of R a ;

each R 1 is independently selected from hydrogen, C 1 -C 6 alkyl, monocyclic aralkyl, C 1 -C 6 hydroxyalkyl, halo, C 1 -C 6 haloalkyl, —N(R 2 )(R 2 ), and —OR 2 ;

each R 2 is independently selected from hydrogen, hydroxyl, halo, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 hydroxyalkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl, and heterocyclylalkyl; wherein each of C 1 -C 6 alkyl, cycloalkyl and heterocyclyl is substituted with 0-5 occurrences of R b , or 2 R 2 together with the carbon or nitrogen atom to which they are attached form a cycloalkyl or heterocyclyl ring;

each R a and R b is independently selected from halo, hydroxyl, —C(O)R′, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, C 1 -C 6 hydroxyalkyl, —NR′R′, and cycloalkyl; wherein cycloalkyl is substituted with 0-5 occurrences of R′;

R′ is hydrogen, hydroxyl, or C 1 -C 6 alkyl; and

m, p, and q are each independently 0, 1, 2, 3, or 4.

2. The compound of claim 1 , wherein L is —(C(R 2 )(R 2 )) m —.

3. The compound of claim 2 , wherein X and Y are CR 1 .

4. The compound of claim 2 , wherein Z is phenyl.

5. The compound of claim 2 , wherein Z is pyridinyl.

6. The compound of claim 2 , wherein Z is isoxazolyl.

7. The compound of claim 2 , wherein Z is pyrazolyl.

8. The compound of claim 2 , wherein Z is dihydroisoquinolinyl.

9. The compound of claim 1 , wherein the compound is a compound of Formula II(a):

or a pharmaceutically acceptable salt thereof.

10. The compound of claim 9 , wherein Z is phenyl.

11. The compound of claim 9 , wherein Z is pyridinyl.

12. The compound of claim 9 , wherein Z is isoxazolyl.

13. The compound of claim 9 , wherein Z is pyrazolyl.

14. The compound of claim 9 , wherein Z is dihydroisoquinolinyl.

15. The compound of claim 9 , wherein R C is piperidinyl.

16. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a compound of claim 1 .

17. A method of treating mastocytosis comprising administering to a patient in need thereof a therapeutically effective amount of a compound of claim 1 or a pharmaceutical composition of claim 16 .

18. A method of treating gastrointestinal stromal tumor, the method comprising administering to a patient in need thereof a therapeutically effective amount of a compound of claim 1 or a pharmaceutical composition of claim 16 .

19. A method of treating acute myeloid leukemia, the method comprising administering to a patient in need thereof a therapeutically effective amount of a compound of claim 1 or a pharmaceutical composition of claim 16 .

20. The method of claim 17 , wherein the mastocytosis is selected from cutaneous mastocytosis (CM) and systemic mastocytosis (SM).

21. The method of claim 20 , wherein the systemic mastocytosis is selected from indolent systemic mastocytosis (ISM), smoldering systemic mastocytosis (SSM), aggressive systemic mastocytosis (ASM), SM with associated hematologic non-mast cell lineage disease (SM-AHNMD), and mast cell leukemia (MCL).