Bicyclic sulfonamide compounds as sodium channel inhibitors

A compound of Formula I, or a pharmaceutically acceptable salt thereof,

• wherein:
• each of A1 and A2 is, independently, CRa or N, provided no more than one of A1and A2 is N;
• wherein each Ra is independently H, halo, —NRcRc, —OH, hydroxyC1-6alkyl, —C1-6alkyl, —OC1-6alkyl, —C1-6haloalkyl, —OC1-6haloalkyl or —CN, and
• Ra is H, —C1-6alkyl or acetyl;
• R1 is a 6 membered aryl or heteroaryl, wherein the aryl or heteroaryl is substituted with from 1 to 4 substituents independently selected from A, halo, OH, —NRbRb, —C1-6alkyl, —OC1-6alkyl, —OC1-6alkylCF3, —OC1-6alkylCN, —(CRcRc)mCN, —C1-6alkylOC1-6alkyl, —CF3, —CHF2, —CH2F, —OCF3, —OCHF2, —OCH2F, —(CRcRc)mA, —N(Rc)(CRcRc)mA, —O(CRcRc)mA, —O(CRcRc)mOA or —C(═O)A, provided at least one substituent on R1 is —(CRcRc)mA, —N(Rc)(CRcRc)mA, —O(CRcRc)mA, —O(CRcRc)mOA or —C(═O)A;
• A is a 4 to 9 membered aryl, heteroaryl or heterocycloalkyl group, where the heteroaryl or heterocycloalkyl group can have from 1 to 3 heteroatoms independently selected from O, N or S, or a 3 to 6 membered cycloalkyl group, and the aryl, heteroaryl, heterocycloalkyl or cycloalkyl group can be unsubstituted or substituted with from 1 to 4 substituents independently selected from halo, —NRbRb, —C1-6alkyl, —OC1-6alkyl, —(CRcRc)mOH, hydroxyC1-6alkyl, —CF3, —CHF2, —CH2F, —OCF3, —OCHF2, —OCH2F, —CN, —C(═O)NRbRb, —O(CRcRc)mB or —(CRcRc)mB;
• B is a 3 to 5 membered cycloalkyl group that can be unsubstituted or substituted with from 1 to 4 substituents independently selected from Cl, F, Br, —NHCH3, —N(CH3)2, —C1-4alkyl, —OC1-4alkyl, —CF3, —CHF2, —CH2F, —OCF3, —OCHF2, —OCH2F or —CN;
• R2 is a 5 to 6 membered aryl or heteroaryl, where the heteroaryl can have from 1 to 3 heteroatoms independently selected from O, N or S, and the aryl and heteroaryl group can be unsubstituted or substituted with from 1 to 4 substituents independently selected from halo, —NRbRb, —C1-6alkyl, —OC1-6alkyl, —(CRcRc)nNRbRb, —CF3, —CHF2, —CH2F, —OCF3, —OCHF2, —OCH2F, —CN or —C(═O)NRbRb;
• each Rb is independently H or —C1-6alkyl;
• each Rc is independently H or —C1-6alkyl;
• and
• each Rd is independently H, halo, —CN, —NRcRc, —OH, —C1-6alkyl, —C1-6haloalkyl, —OC1-6haloalkyl or —OC1-6alkyl;
• each Re is independently H, halo, —CN, —NRcRc, —OH, —C1-6alkyl or —OC1-6alkyl;
• each n is independently 0, 1, 2, 3 or 4;
• and
• each m is independently 0, 1, 2, 3 or 4.