A compound of formula I wherein R 1, R 2, R 3 and R 4 are independently selected from C 1-6 alkyl, haloC 1-6 alkyl, hydrogen, halogen, cyano, amino, C 1-6 alkylamino, diC 1-6 alkylamino, pyrrolidinyl and OR 6; R 5 is hydrogen or C 1-6 alkyl; R 6 is hydrogen; C 1-6 alkyl; haloC 1-6 alkyl; C 3-7 cycloalkylC 1-6 alkyl; phenylC 1-6 alkyl; hydroxyC 1-6 alkyl; C 1-6 alkoxyC 1-6 alkyl; carboxyC 1-6 alkyl; C 1-6 alkylsulfanylC 1-6 alkyl; C 1-6 alkylsulfonylC 1-6 alkyl; cyanoC 1-6 alkyl; aminoC 1-6 alkyl; C 1-6 alkylaminoC 1-6 alkyl; diC 1-6 alkylaminoC 1-6 alkyl; C 1-6 alkylcarbonylaminoC 1-6 alkyl; C 1-6 alkylsulfonylaminoC 1-6 alkyl; C 1-6 alkoxycarbonylaminoC 1-6 alkyl; pyrazolylC 1-6 alkyl; triazolylC 1-6 alkyl or heterocycloalkylC 1-6 alkyl, wherein heterocycloalkyl is N -containing monocyclic heterocycloalkyl; Ar is phenyl; phenyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; thienyl; thienyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; benzothiophenyl; benzothiophenyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; pyridinyl; pyridinyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; pyrimidinyl; pyrimidinyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; pyrrolyl; pyrrolyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; pyrazolyl; pyrazolyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; thiazolyl; or thiazolyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; or pharmaceutically acceptable salts, or enantiomers thereof. R 1, R 2, R 3 and R 4 are independently selected from C 1-6 alkyl, haloC 1-6 alkyl, hydrogen, halogen, cyano, amino, C 1-6 alkylamino, diC 1-6 alkylamino, pyrrolidinyl and OR 6; R 5 is hydrogen or C 1-6 alkyl; R 6 is hydrogen; C 1-6 alkyl; haloC 1-6 alkyl; C 3-7 cycloalkylC 1-6 alkyl; phenylC 1-6 alkyl; hydroxyC 1-6 alkyl; C 1-6 alkoxyC 1-6 alkyl; carboxyC 1-6 alkyl; C 1-6 alkylsulfanylC 1-6 alkyl; C 1-6 alkylsulfonylC 1-6 alkyl; cyanoC 1-6 alkyl; aminoC 1-6 alkyl; C 1-6 alkylaminoC 1-6 alkyl; diC 1-6 alkylaminoC 1-6 alkyl; C 1-6 alkylcarbonylaminoC 1-6 alkyl; C 1-6 alkylsulfonylaminoC 1-6 alkyl; C 1-6 alkoxycarbonylaminoC 1-6 alkyl; pyrazolylC 1-6 alkyl; triazolylC 1-6 alkyl or heterocycloalkylC 1-6 alkyl, wherein heterocycloalkyl is N -containing monocyclic heterocycloalkyl; Ar is phenyl; phenyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; thienyl; thienyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; benzothiophenyl; benzothiophenyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; pyridinyl; pyridinyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; pyrimidinyl; pyrimidinyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; pyrrolyl; pyrrolyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; pyrazolyl; pyrazolyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy; thiazolyl; or thiazolyl substituted by one, two or three groups independently selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxy, halogen and phenylC 1-6 alkoxy;