A compound of formula, wherein R 1 is naphthyridinyl; pyrazolo[1,5-a]pyrimidinyl which is unsubstituted or substituted by cyano; pyridinyl which is substituted by 2-oxo-3H-1,3,4-oxadiazolyl; amino; aminoC 1-6 alkyl; aminocarbonyl; aminocarbonylC 1-6 alkyl; C 1-6 alkoxyaminocarbonyl; C 1-6 alkoxyC 1-6 alkylaminocarbonyl; C 1-6 alkoxyC 1-6 alkylC 3-7 cycloalkylaminocarbonyl; C 1-6 alkyl; C 1-6 alkyl-1,3,4-oxadiazolylC 1-6 alkyl; C 1-6 alkylaminocarbonyl; cyano; halogen; hydroxyC 1-6 alkyl; imidazolylC 1-6 alkyl; morpholinyl; or morpholinylC 1-6 alkyl; or pyrimidinyl which is unsubstituted or substituted by amino; aminoC 1-6 alkoxy; aminoC 1-6 alkyl; aminocarbonyl; azetidinyloxy; C 1-6 alkoxy; C 1-6 alkoxyaminocarbonylC 3-7 cycloalkyl; C 1-6 alkoxyC 1-6 alkylamino; C 1-6 alkyl; C 1-6 alkylamino; C 1-6 alkylaminocarbonylC 3-7 cycloalkyl; carboxy(C 3-7 cycloalkyl)C 1-6 alkylamino; carboxyC 1-6 alkoxy; carboxyC 1-6 alkylamino; carboxyC 3-7 cycloalkyl; hydroxyC 1-6 alkyl; morpholinyl; piperazinyl; piperidinylamino; piperidinyloxy; pyrrolidinylamino; pyrrolidinyloxy; or tetrahydrofuranylamino; R 2 is 4,5,6,7-tetrahydropyrazolo[3,4-c]pyridinyl substituted by cyano; pyrazolyl which is substituted once or twice by substituents independently selected from haloC 1-6 alkyl; aminoC 1-6 alkyl; aminocarbonyl; C 1-6 alkyl; cyano; and hydroxyC 1-6 alkyl; pyrrolo[3,4-c]pyrazolyl which is unsubstituted or substituted by cyano or haloC 1-6 alkyl; or thiazolyl; R 3 is H or halogen; R 4 is halogen; R 5 is H or halogen; R 6 is C 1-6 alkyl; or pharmaceutically acceptable salt thereof. R 1 is naphthyridinyl; pyrazolo[1,5-a]pyrimidinyl which is unsubstituted or substituted by cyano; pyridinyl which is substituted by 2-oxo-3H-1,3,4-oxadiazolyl; amino; aminoC 1-6 alkyl; aminocarbonyl; aminocarbonylC 1-6 alkyl; C 1-6 alkoxyaminocarbonyl; C 1-6 alkoxyC 1-6 alkylaminocarbonyl; C 1-6 alkoxyC 1-6 alkylC 3-7 cycloalkylaminocarbonyl; C 1-6 alkyl; C 1-6 alkyl-1,3,4-oxadiazolylC 1-6 alkyl; C 1-6 alkylaminocarbonyl; cyano; halogen; hydroxyC 1-6 alkyl; imidazolylC 1-6 alkyl; morpholinyl; or morpholinylC 1-6 alkyl; or pyrimidinyl which is unsubstituted or substituted by amino; aminoC 1-6 alkoxy; aminoC 1-6 alkyl; aminocarbonyl; azetidinyloxy; C 1-6 alkoxy; C 1-6 alkoxyaminocarbonylC 3-7 cycloalkyl; C 1-6 alkoxyC 1-6 alkylamino; C 1-6 alkyl; C 1-6 alkylamino; C 1-6 alkylaminocarbonylC 3-7 cycloalkyl; carboxy(C 3-7 cycloalkyl)C 1-6 alkylamino; carboxyC 1-6 alkoxy; carboxyC 1-6 alkylamino; carboxyC 3-7 cycloalkyl; hydroxyC 1-6 alkyl; morpholinyl; piperazinyl; piperidinylamino; piperidinyloxy; pyrrolidinylamino; pyrrolidinyloxy; or tetrahydrofuranylamino; pyrazolo[1,5-a]pyrimidinyl which is unsubstituted or substituted by cyano; pyridinyl which is substituted by 2-oxo-3H-1,3,4-oxadiazolyl; amino; aminoC 1-6 alkyl; aminocarbonyl; aminocarbonylC 1-6 alkyl; C 1-6 alkoxyaminocarbonyl; C 1-6 alkoxyC 1-6 alkylaminocarbonyl; C 1-6 alkoxyC 1-6 alkylC 3-7 cycloalkylaminocarbonyl; C 1-6 alkyl; C 1-6 alkyl-1,3,4-oxadiazolylC 1-6 alkyl; C 1-6 alkylaminocarbonyl; cyano; halogen; hydroxyC 1-6 alkyl; imidazolylC 1-6 alkyl; morpholinyl; or morpholinylC 1-6 alkyl; or pyrimidinyl which is unsubstituted or substituted by amino; aminoC 1-6 alkoxy; aminoC 1-6 alkyl; aminocarbonyl; azetidinyloxy; C 1-6 alkoxy; C 1-6 alkoxyaminocarbonylC 3-7 cycloalkyl; C 1-6 alkoxyC 1-6 alkylamino; C 1-6 alkyl; C 1-6 alkylamino; C 1-6 alkylaminocarbonylC 3-7 cycloalkyl; carboxy(C 3-7 cycloalkyl)C 1-6 alkylamino; carboxyC 1-6 alkoxy; carboxyC 1-6 alkylamino; carboxyC 3-7 cycloalkyl; hydroxyC 1-6 alkyl; morpholinyl; piperazinyl; piperidinylamino; piperidinyloxy; pyrrolidinylamino; pyrrolidinyloxy; or tetrahydrofuranylamino; R 2 is 4,5,6,7-tetrahydropyrazolo[3,4-c]pyridinyl substituted by cyano; pyrazolyl which is substituted once or twice by substituents independently selected from haloC 1-6 alkyl; aminoC 1-6 alkyl; aminocarbonyl; C 1-6 alkyl; cyano; and hydroxyC 1-6 alkyl; pyrrolo[3,4-c]pyrazolyl which is unsubstituted or substituted by cyano or haloC 1-6 alkyl; or thiazolyl; pyrazolyl which is substituted once or twice by substituents independently selected from haloC 1-6 alkyl; aminoC 1-6 alkyl; aminocarbonyl; C 1-6 alkyl; cyano; and hydroxyC 1-6 alkyl; pyrrolo[3,4-c]pyrazolyl which is unsubstituted or substituted by cyano or haloC 1-6 alkyl; or thiazolyl; R 3 is H or halogen; R 4 is halogen; R 5 is H or halogen; R 6 is C 1-6 alkyl;