Patent ID: 8338441

Claim:
A compound of Formula I wherein R 1 is (C 1-6 )alkyl, (C 2-6 )alkenyl or (C 3-6 )cycloalkyl, wherein the (C 1-6 )alkyl is optionally substituted with —O(C 1-6 )alkyl or —S(C 1-6 )alkyl; R 2 is (C 1-8 )alkyl or (C 3-8 )cycloalkyl, wherein the (C 3-8 )cycloalkyl is optionally substituted with (C 1-6 )alkyl; R 3 is aryl, wherein the aryl is optionally fused to one or more cycles, at least one of which is a heterocycle, to form a heteropolycycle, and wherein the aryl or heteropolycycle is optionally substituted with 1 to 4 substituents each independently selected from (C 1-6 )alkyl, halo and —O(C 1-6 )alkyl; R 4 is (C 1-6 )alkyl, —CN, halo, (C 1-6 )haloalkyl, (C 3-5 )cycloalkyl, or —O(C 1-6 )alkyl; and a is a double bond, R 6 is absent and R 5 is R 51 or —(C 1-3 )alkyl-R 51 ; or a is a single bond and R 5 and R 6 are joined, together with the atoms to which they are bonded, to form a 5-membered ring optionally having 1 to 3 further heteroatoms each independently selected from O, N and S, wherein the 5-membered ring is optionally substituted with 1 to 3 R 51 substituents; wherein R 51 is in each case independently selected from R 52 , —OR 53 , —N(R 54 )R 53 , —C(═O)R 52 , —C(═O)OR 53 , —C(═O)N(R 54 )R 53 , —OC(═O)N(R 54 )R 53 , —N(R 54 )C(═O)R 52 , —N(R 54 )C(═O)N(R 54 )R 53 and —N(R 54 )C(═O)OR 53 ; wherein R 52 is in each case independently selected from R 53 , (C 2-8 )alkenyl and (C 2-8 )alkynyl, R 53 is in each case independently selected from (C 1-8 )alkyl, (C 3-8 )cycloalkyl, (C 3-8 )cycloalkyl-(C 1-6 )alkyl-, aryl, aryl-(C 1-6 )alkyl-, Het, and Het-(C 1-6 )alkyl-, and R 54 is in each case independently selected from H and (C 1-3 )alkyl; wherein each of R 52 and R 53 is optionally substituted with 1 to 3 substituents each independently selected from R 55 , halo, —CN, —OR 56 , —SR 56 , —SOR 56 , —SO 2 R 56 , —N(R 54 )R 56 , —N(R 54 )C(═O)R 55 , —N(R 54 )C(═O)N(R 54 )R 56 , —N(R 54 )C(═O)OR 56 , —OC(═O)N(R 54 )R 56 , —C(═O)R 55 , —C(═O)OR 56 , and —CON(R 54 )R 56 , wherein R 55 is in each case independently selected from R 56 , (C 2-8 )alkenyl and (C 2-8 )alkynyl, and R 56 is in each case independently selected from H, (C 1-8 )alkyl, (C 3-8 )cycloalkyl, (C 3-8 )cycloalkyl-(C 1-6 )alkyl-, aryl, aryl-(C 1-6 )alkyl-, Het, and Het-(C 1-6 )alkyl-, wherein each of R 55 and R 56 is, where possible, in each case independently optionally substituted with 1 to 3 substituents each independently selected from (C 1-6 )alkyl, (C 1-6 )haloalkyl, halo, —OH, —O(C 1-6 )alkyl, —NH 2 , —NH(C 1-6 )alkyl, —N((C 1-6 )alkyl) 2 and —NH(C═O)(C 1-6 )alkyl; wherein Het is a 4- to 7-membered saturated, unsaturated or aromatic heterocycle having 1 to 4 heteroatoms each independently selected from O, N and S, or a 7- to 14-membered saturated, unsaturated or aromatic heteropolycycle having wherever possible 1 to 5 heteroatoms, each independently selected from O, N and S; or a salt thereof.