Patent ID: 8288538

Claim:
A compound represented by the following formula or a salt thereof: wherein R 1 represents azetidin-1-yl optionally substituted with a substituent selected from Substituent Group E, pyrrolidin-1-yl optionally substituted with a substituent selected from Substituent Group E, piperidin-1-yl optionally substituted with a substituent selected from Substituent Group E, piperazin-1-yl optionally substituted with a substituent selected from Substituent Group E, diazepan-1-yl optionally substituted with a substituent selected from Substituent Group E or morpholin-4-yl optionally substituted with a substituent selected from Substituent Group E wherein Substituent Group E substituents are methyl, ethyl, dimethylamino, azetidinyl, pyrrolidinyl, piperidinyl or piperazinyl, wherein each group included in Substituent Group E may be substituted with hydroxyl, methyl, dimethylamino, azetidinyl, pyrrolidinyl or piperidinyl or R 1 represents a group represented by the formula â€”NR 11e R 11f , wherein R 11e represents hydrogen or C 1-6 alkyl, and R 11f represents C 1-6 alkyl, pyrrolidin-3-yl, piperidin-3-yl, piperidin-4-yl or tetrahydropyran-4-yl, and R 11f may be substituted with a substituent selected from Substituent Group D, wherein Substituent Group D substituents are halogen, hydroxyl, mercapto, cyano, formyl, oxo, C 1-6 alkyl, C 3-10 cycloalkyl, alkoxy, amino, mono-C 1-6 alkylamino, di-C 1-6 alkylamino, azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, diazepanyl or a group represented by -T 4 -T 5 , wherein T 4 represents carbonyl or sulfonyl and T 5 represents C 1-6 alkyl, C 3-10 cycloalkyl, azetidinyl, pyrrolidinyl, piperidinyl, hydroxyl, C 1-6 alkoxy, amino, mono-C 1-6 alkylamino or di-C 1-6 alkylamino, where each group included in Substituent Group D may be substituted with hydroxyl, C 1-6 alkyl, di-C 1-6 alkylamino, azetidinyl or pyrrolidinyl; R 2 and R 3 represent hydrogen; R 4 , R 5 , R 6 and R 7 may be the same or different and each represents hydrogen, halogen, hydroxyl, cyano, trifluoromethyl, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 1-6 alkoxy, amino, mono-C 1-6 alkylamino, di-C 1-6 alkylamino or a group represented by the formula â€”COâ€”R 12 , wherein R 12 represents hydrogen, hydroxyl, C 1-6 alkyl, C 1-6 alkoxy, amino, mono-C 1-6 alkylamino or di-C 1-6 alkylamino; R 8 represents hydrogen or C 1-6 alkyl; R 9 represents phenylamino optionally substituted with halogen; n represents an integer of 1 or 2; and X represents a group represented by the formula â€”C(R 10 )â• or nitrogen, wherein R 10 represents hydrogen, halogen, cyano, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl or a group represented by the formula â€”COâ€”R 12 , wherein R 12 represents the same meaning as recited above.