Substituted benzoxazoles and methods of use thereof

1. A compound of Formula I:

or a pharmaceutically acceptable salt thereof, wherein:

R 1 is C 1-8 alkyl, C 1-8 haloalkyl, C 1-8 alkoxy, C 3-12 carbocycle, C-linked C 2-11 heterocycle or —NR 1A R 1B , wherein R 1A and R 1B are each independently selected from the group consisting of hydrogen, C 1-8 alkyl, C 1-8 alkoxy, (6-10 membered aryl)-(X R1 ) 0-1 —, and 5-10 membered heteroaryl)-(X R1 ) 0-1 —, and wherein R 1A and R 1B are optionally combined to form a 3 to 8 membered heterocyclic ring optionally comprising 1 additional heteroatoms selected from N, O and S as ring vertex and optionally fused thereto is a benzene or pyridine ring; X R1 is selected from the group consisting of C 1-4 alkylene, C 1-4 heteroalkylene, C 2-4 alkenylene, and C 2-4 alkynylene; and wherein the aliphatic and aromatic portions of R 1 are optionally substituted with from 1 to 5 R R1 substituents selected from the group consisting of C 1-8 alkyl, C 1-8 haloalkyl, oxo (═O), F, Cl, Br, I, —OH, —CN, —NO 2 , —(X 1R ) 0-1 —NR R1a R R1b , —(X 1R ) 0-1 OR R1a , —(X 1R ) 0-1 SR R1a , —(X 1R ) 0-1 N(R R1a )C(═O)OR R1c , —(X 1R ) 0-1 OC(═O)N(R R1a )(R R1b ), —(X 1R ) 0-1 N(R R1a )C(═O)N(R R1a )(R R1b ), —(X 1R ) 0-1 C(═O)N(R R1a )(R R1b ), —(X 1R ) 0-1 N(R R1a )C(═O)R R1b , —(X 1R ) 0-1 C(═O)OR R1a , —(X 1R ) 0-1 OC(═O)R R1a , —(X 1R ) 0-1 —P(═O)(OR R1a )(R R1b ), —(X 1R ) 0-1 S(O) 1-2 R R1c , —(X 1R ) 0-1 S(O) 1-2 N(R R1a )(R R1b ), —(X 1R ) 0-1 N(R R1a )S(O) 1-2 N(R R1a )(R R1b ) and —(X 1R ) 0-1 N(R R1a )S(O) 1-2 (R R1c ), wherein X 1R is selected from the group consisting of C 1-4 alkylene, C 1-4 heteroalkylene, C 2-4 alkenylene and C 2-4 alkynylene; wherein R R1a and R R1b are independently selected from the group consisting of hydrogen, C 1-8 alkyl, C 1-8 haloalkyl, C 3-8 carbocycle, phenyl, benzyl, C 5-6 heteroaryl and C 2-7 heterocycle; R R1c is selected from the group consisting of C 1-8 alkyl, C 1-8 haloalkyl, C 3-8 carbocycle, phenyl, benzyl, C 5-6 heteroaryl and C 2-7 heterocycle;

R N is hydrogen, C 1-4 alkyl or C 1-4 haloalkyl;

R 2 and R 3 are each independently selected from the group consisting of H, F, Cl, Br, I, —CN, C 1-8 alkyl, C 1-8 haloalkyl and C 1-8 alkoxy;

R 4 is selected from the group consisting of H, F, Cl, Br, I, —CN, C 1-8 alkyl, C 1-8 haloalkyl, C 1-8 alkoxy, C 3-8 carbocycle, C 2-7 heterocycle, phenyl and 5-6 membered heteroaryl comprising 1 to 3 heteroatoms selected from N, O and S, wherein said 5-6 membered heteroaryl is further optionally substituted with from 1 to 3 R 5 substituents selected from F, Cl, Br, I, —CN, C 1-4 alkyl, C 1-4 haloalkyl and C 1-4 alkoxy;

L is a linker selected from the group consisting of C 1-4 alkylene, C 2-4 alkenylene, C 2-4 alkynylene, and C 1-4 heteroalkylene, wherein L is optionally substituted with from 1 to 3 R L substituents selected from the group consisting of ═O, C 1-4 alkyl, C 1-4 haloalkyl and C 1-4 acyl;

the subscript m represents the integer 0 or 1;

X 1 and X 2 are each independently selected from the group consisting of absent, —O—, —S(O)—, —S(O) 2 — and —N(R X )— wherein R x is H, C 1-8 alkyl, C 1-8 acyl or —S(O) 2 (C 1-8 alkyl), and wherein if the subscript m is 0 then one of X 1 or X 2 is absent;

the subscript n is an integer from 0 to 5;

A is selected from the group consisting of hydrogen, C 3 -C 20 carbocycle, C 3 -C 20 heterocycle, aryl, and heteroaryl, wherein if A is hydrogen then the subscript n is 0; and

R A is selected from the group consisting of C 1-8 alkyl, C 1-8 haloalkyl, F, Cl, Br, I, —OH, —CN, —NO 2 , carbocycle, heterocycle, heteroaryl, —(X RA ) 0-1 NR A1 R A2 , —(X RA ) 0-1 OR A1 , —(X RA ) 0-1 SR A1 , —(X RA ) 0-1 N(R A1 )C(═O)OR A3 , —(X RA ) 0-1 OC(═O)N(R A1 )(R A2 ), —(X RA ) 0-1 N(R A1 )C(═O)N(R A1 )(R A2 ), —(X RA ) 0-1 C(═O)N(R A1 )(R A2 ), —(X RA ) 0-1 N(X RA )C(═O)R A2 , —(X RA ) 0-1 C(═O)OR A1 , —(X RA ) 0-1 OC(═O)R A1 , —P(═O)(OR A1 )(OR A2 ), —(X RA ) 0-1 S(O) 1-2 R A3 , —(X RA ) 0-1 S(O) 1-2 N(R A1 )(R A2 ), —(X RA ) 0-1 N(R A1 )S(O) 1-2 N(R A1 )(R A2 ) and —(X RA ) 0-1 N(R A1 )S(O) 1-2 (R A3 ), wherein X RA is selected from the group consisting of C 1-4 alkylene, C 1-4 heteroalkylene, C 2-4 alkenylene and C 2-4 alkynylene; wherein R A1 and R A2 are independently selected from the group consisting of hydrogen, C 1-8 alkyl, C 1-8 haloalkyl, C 3-8 carbocycle, tetrahydronaphthalene, phenyl, benzyl, C 5-6 heteroaryl and C 2-7 heterocycle; R A3 is selected from the group consisting of C 1-8 alkyl, C 1-8 haloalkyl, C 3-8 carbocycle, tetrahydronaphthalene, phenyl, benzyl, C 5-6 heteroaryl and C 2-7 heterocycle; and wherein the aliphatic and aromatic portions of a R A substitutent is optionally substituted with from 1 to 5 R RA substitutents selected from, F, Cl, Br, I, —NH 2 , —OH, —CN, —NO 2 , ═O, C 1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxy, C 1-4 (halo)alkyl-C(═O)—, C 1-4 (halo)alkyl-S(O) 0-2 —, C 1-4 (halo)alkyl-C(═O)N(H)—, C 1-4 (halo)alkyl-N(H)—C(═O)—, ((halo)alkyl) 2 N—C(═O)—, C 1-4 (halo)alkyl-OC(═O)N(H)—, C 1-4 (halo)alkyl-OC(═O)N(H)—, (halo)alkyl-N(H)—C(═O)O—, ((halo)alkyl) 2 N—C(═O)O—, C 1-4 alkylamino, C 1-4 dialkylamino, C 3-6 carbocycle, C 3-6 cycloalkoxy, C 2-5 heterocycloalkoxy and tetrahydronaphthalene.

2. The compound of claim 1 , wherein the compound has the formula

3. The compound of claim 1 wherein R 4 is F, Cl, Br, I, —CN, C 1-8 alkyl, C 1-8 haloalkyl, C 1-8 alkoxy, or C 3-8 carbocycle.

4. The compound of claim 1 wherein R 4 is Cl or C 3-8 cyclopropyl.

5. The compound of claim 1 wherein R 1 is C 1-8 alkyl or C 3-12 carbocycle, wherein the aliphatic portions of R 1 are optionally substituted with from 1 to 5 R R1 substituents.

6. The compound of claim 5 wherein R 1 is methyl, cyclopropyl, or 2-methoxyethyl.

7. The compound of claim 1 wherein R 1 is selected from the group consisting of: —NH(CH 3 ), —N(CH 3 ) 2 ,

8. The compound of claim 1 wherein X 1 is —O— or —N(H)—; X 2 is absent; the subscript m is 1; and -(L)- is an optionally substituted group selected from the group consisting of C 1-4 alkylene, C 2-4 alkenylene or C 2-4 alkynylene.

9. The compound of claim 1 wherein A is an optionally substituted ring selected from the group consisting of cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, adamantane, bicyclo[2.1.1]hexane, bicyclo[2.2.2]octane, bicyclo[2.2.1]heptane, bicyclo[3.1.1]heptane, bicyclo[3.2.1]octane, bicyclo[4.1.1]octane, bicyclo[3.3.1]nonane and 1,2,3,4-tetrahydro-1,4-methanonaphthalene, 1,2,3,4-tetrahydroisoquinoline, cubane, spiro[2,5]octane, tetrahydronaphthalene and chromane.

10. The compound of claim 9 , wherein ring A is an optionally substituted ring selected from the group consisting of cyclopropane, cyclobutane, cyclopentane, cyclohexane, adamantane, cubane, bicyclo[2.2.2]octane, bicyclo[3.1.1]heptane, bicyclo[2.2.1]heptane, spiro[2,5]octane, tetrahydronaphthalene and chromane.

11. The compound of claim 1 wherein ring A is selected from the group consisting of

12. The compound of claim 1 wherein ring A is an optionally substituted ring selected from the group consisting of azetidine, pyrrolidine, piperidine, homopiperidine, (1R,5S)-8-azabicyclo[3.2.1]octane, 3-oxa-9-azabicyclo[3.3.1]nonane, (1 s,4s)-7-azabicyclo[2.2.1]heptane, (1R,4S)-5-azabicyclo-[2.1.1]hexane, 7-(trifluoromethyl)-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine and quinuclidine.

13. The compound of claim 1 wherein A is selected from the group consisting of

14. The compound of claim 1 wherein R A is selected from the group consisting of C 1-4 alkyl, C 1-4 haloalkyl, C 3-5 carbocycle, C 2-4 heterocycle, F, Cl, Br, I, —OH, —NH 2 , —CN, —NO 2 , C 1-4 alkoxy, —C(═O)—N(R A1 )(R A2 ) and —N(R A1 )(R A2 ).

15. The compound of claim 14 , wherein R A is methyl, trifluromethyl, difluoromethyl, monofluoromethyl, ethyl, pentafluoroethyl, cyclopropyl, —F, Cl, —OH, —NH 2 or —CN.

16. The compound of claim 1 wherein A is selected from the group consisting of benzene, pyridine, pyrimidine, pyrazine, pyridazine, benzothiazole, indole, quinoline, isoquinoline, quinazoline, benzoxazole, benzimidazole, pyrrolopyridine, dihydrobenzofuran, dihydroindene, and indoline.

17. The compound of claim 16 wherein R A is selected from the group consisting of C 1-4 alkyl, C 1-4 haloalkyl, C 3-5 carbocycle, 3-5 membered heterocycle, C 1-4 haloalkoxy, F, Cl, Br, I, —OH, —NH 2 , —CN, —NO 2 , C 1-4 alkoxy, —(X RA ) 0-1 OR A1 , —C(═O)—N(R A1 )(R A2 ) and —N(R A1 )(R A2 ), wherein the aliphatic portions of a R A are optionally substituted with from 1 to 5 R RA substitutents selected from, F, Cl, Br, and I.

18. The compound of claim 16 wherein R A is methyl, trifluromethyl, difluoromethyl, monofluoromethyl, ethyl, pentafluoroethyl, cyclopropyl, n-propoxy, isopropoxy, sec-butyloxy, n-butyloxy, tert-butyloxy, —F, Cl, —OH, —NH 2 or —CN.

19. The compound of claim 1 wherein

is selected from:

20. The compound of claim 1 wherein

is selected from:

21. The compound of claim 1 , selected from the group consisting of:

22. A pharmaceutical composition comprising a compound of Formula I as described in claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient.

23. A method of treating a sodium channel-mediated disease or condition in a mammal selected from the group consisting of pain, depression, cardiovascular diseases, respiratory diseases, and psychiatric diseases, and combinations thereof, wherein the method comprises administering to the mammal in need thereof a therapeutically effective amount of a compound of Formula I as described in claim 1 , or a pharmaceutically acceptable salt thereof.

24. The method of claim 23 , wherein said disease or condition is selected from the group consisting of neuropathic pain, inflammatory pain, visceral pain, cancer pain, chemotherapy pain, trauma pain, surgical pain, post-surgical pain, childbirth pain, labor pain, neurogenic bladder, ulcerative colitis, chronic pain, persistent pain, peripherally mediated pain, centrally mediated pain, chronic headache, migraine headache, sinus headache, tension headache, phantom limb pain, dental pain, peripheral nerve injury or a combination thereof.