A compound of the formula, or a pharmaceutically acceptable salt thereof: wherein n represents 0 or 1; X represents CH or N; R 1 represents: - phenyl, optionally substituted by 1, 2 or 3 substituents independently selected from R 10; - a group G 1 selected from furan-2-yl, pyridin-2-yl, pyrimidin-2-yl, pyrimidin-4-yl and pyrazin-2-yl, wherein G 1 is optionally substituted by 1, 2 or 3 substituents independently selected from R 10; or - a group G 2 selected from isothiazolo[4,5-b]pyridin-3-yl, isothiazolo[4,5-b]pyrazin-3-yl, benzo[d]isothiazol-3-yl, indazol-3-yl, benzo[d]isoxazol-3-yl, pyrido[3,2-d]pyrimidin-4-yl, [1,7]naphthyridin-8-yl and imidazol[1,2-a]pyrazin-8-yl, wherein G 2 is optionally substituted by 1, 2 or 3 substituents independently selected from R 11; R 2, R 3 and R 4 independently represent hydrogen, halogen or C 1-3 alkyl; R 5 represents C 1-3 alkyl, halogen-C 1-3 alkyl or C 1-3 alkoxy-C 1-3 alkyl; R 6 and R 7 independently represent hydrogen or C 1-3 alkyl; R 8 and R 9 independently represent C 1-3 alkyl, halogen-C 1-3 alkyl or C 1-3 alkoxy; or R 8 and R 9 taken together are cyclopropyl; R 10 represents halogen, cyano, hydroxy, halogen-C 1-3 alkoxy, C 1-3 alkoxy or C 1-3 alkoxy-C 1-3 alkoxy; and R 11 represents halogen, cyano, hydroxy, C 1-3 alkyl, halogen-C 1-3 alkyl, halogen-C 1-3 alkoxy, C 1-3 alkoxy, C 1-3 alkoxy-C 1-3 alkyl or C 1-3 alkoxy-C 1-3 alkoxy. n represents 0 or 1; X represents CH or N; R 1 represents: - phenyl, optionally substituted by 1, 2 or 3 substituents independently selected from R 10; - a group G 1 selected from furan-2-yl, pyridin-2-yl, pyrimidin-2-yl, pyrimidin-4-yl and pyrazin-2-yl, wherein G 1 is optionally substituted by 1, 2 or 3 substituents independently selected from R 10; or - a group G 2 selected from isothiazolo[4,5-b]pyridin-3-yl, isothiazolo[4,5-b]pyrazin-3-yl, benzo[d]isothiazol-3-yl, indazol-3-yl, benzo[d]isoxazol-3-yl, pyrido[3,2-d]pyrimidin-4-yl, [1,7]naphthyridin-8-yl and imidazol[1,2-a]pyrazin-8-yl, wherein G 2 is optionally substituted by 1, 2 or 3 substituents independently selected from R 11; - phenyl, optionally substituted by 1, 2 or 3 substituents independently selected from R 10; - a group G 1 selected from furan-2-yl, pyridin-2-yl, pyrimidin-2-yl, pyrimidin-4-yl and pyrazin-2-yl, wherein G 1 is optionally substituted by 1, 2 or 3 substituents independently selected from R 10; or - a group G 2 selected from isothiazolo[4,5-b]pyridin-3-yl, isothiazolo[4,5-b]pyrazin-3-yl, benzo[d]isothiazol-3-yl, indazol-3-yl, benzo[d]isoxazol-3-yl, pyrido[3,2-d]pyrimidin-4-yl, [1,7]naphthyridin-8-yl and imidazol[1,2-a]pyrazin-8-yl, wherein G 2 is optionally substituted by 1, 2 or 3 substituents independently selected from R 11; R 2, R 3 and R 4 independently represent hydrogen, halogen or C 1-3 alkyl; R 5 represents C 1-3 alkyl, halogen-C 1-3 alkyl or C 1-3 alkoxy-C 1-3 alkyl; R 6 and R 7 independently represent hydrogen or C 1-3 alkyl; R 8 and R 9 independently represent C 1-3 alkyl, halogen-C 1-3 alkyl or C 1-3 alkoxy; or R 8 and R 9 taken together are cyclopropyl; R 10 represents halogen, cyano, hydroxy, halogen-C 1-3 alkoxy, C 1-3 alkoxy or C 1-3 alkoxy-C 1-3 alkoxy; and R 11 represents halogen, cyano, hydroxy, C 1-3 alkyl, halogen-C 1-3 alkyl, halogen-C 1-3 alkoxy, C 1-3 alkoxy, C 1-3 alkoxy-C 1-3 alkyl or C 1-3 alkoxy-C 1-3 alkoxy.