A compound represented by the general formula or a pharmacologically acceptable salt thereof: wherein each substituent is defined as follows: R 1 represents a halogen atom, an allyl group, a C3-C6 cycloalkyl group, or a C1-C6 alkyl group optionally substituted by one or two or more groups selected from substituent group a, wherein the substituent group a consists of a C3-C6 cycloalkyl group, a hydroxyl group, a halogen atom, an oxo group, and a phenyl group; R 2 represents a hydrogen atom; R 3 represents a hydrogen atom; R 4 represents a hydrogen atom or a methyl group; and A represents a piperidine group substituted by one or two or more groups selected from substituent group c, wherein the substituent group c consists of a C1-C6 alkylsulfonyl group, an aminocarbonyl group, a di-C1-C6 alkylaminocarbonyl group, a C1-C6 alkoxy-C1-C6 alkylcarbonyl group, a di-C1-C6 alkylaminosulfonyl group, a C1-C6 alkylcarbonyl group optionally substituted by one or two or more groups selected from substituent group d, a C1-C6 alkoxycarbonyl group optionally substituted by one or two or more groups selected from substituent group d, a heterocyclic group optionally substituted by one or two or more groups selected from substituent group d, a benzoyl group optionally substituted by one or two or more groups selected from substituent group d, and a benzyl group optionally substituted by one or two or more groups selected from substituent group d, wherein the substituent group d consists of a halogen atom, a carboxy group, an oxo group, an aminocarbonyl group, a C1-C6 alkoxy group, a C1-C6 alkoxycarbonyl group, a C1-C6 alkylaminocarbonyl group, a di-C1-C6 alkylaminocarbonyl group, a heterocycle-carbonyl group, a phenyl group, and a phenylaminocarbonyl group optionally substituted by one or two or more groups selected from substituent group e, wherein the substituent group e consists of a heterocycle-carbonyl group and a heterocycle-C1-C6 alkyl group. R 1 represents a halogen atom, an allyl group, a C3-C6 cycloalkyl group, or a C1-C6 alkyl group optionally substituted by one or two or more groups selected from substituent group a, wherein the substituent group a consists of a C3-C6 cycloalkyl group, a hydroxyl group, a halogen atom, an oxo group, and a phenyl group; R 2 represents a hydrogen atom; R 3 represents a hydrogen atom; R 4 represents a hydrogen atom or a methyl group; and A represents a piperidine group substituted by one or two or more groups selected from substituent group c, wherein the substituent group c consists of a C1-C6 alkylsulfonyl group, an aminocarbonyl group, a di-C1-C6 alkylaminocarbonyl group, a C1-C6 alkoxy-C1-C6 alkylcarbonyl group, a di-C1-C6 alkylaminosulfonyl group, a C1-C6 alkylcarbonyl group optionally substituted by one or two or more groups selected from substituent group d, a C1-C6 alkoxycarbonyl group optionally substituted by one or two or more groups selected from substituent group d, a heterocyclic group optionally substituted by one or two or more groups selected from substituent group d, a benzoyl group optionally substituted by one or two or more groups selected from substituent group d, and a benzyl group optionally substituted by one or two or more groups selected from substituent group d, wherein the substituent group d consists of a halogen atom, a carboxy group, an oxo group, an aminocarbonyl group, a C1-C6 alkoxy group, a C1-C6 alkoxycarbonyl group, a C1-C6 alkylaminocarbonyl group, a di-C1-C6 alkylaminocarbonyl group, a heterocycle-carbonyl group, a phenyl group, and a phenylaminocarbonyl group optionally substituted by one or two or more groups selected from substituent group e, wherein the substituent group e consists of a heterocycle-carbonyl group and a heterocycle-C1-C6 alkyl group. the substituent group c consists of a C1-C6 alkylsulfonyl group, an aminocarbonyl group, a di-C1-C6 alkylaminocarbonyl group, a C1-C6 alkoxy-C1-C6 alkylcarbonyl group, a di-C1-C6 alkylaminosulfonyl group, a C1-C6 alkylcarbonyl group optionally substituted by one or two or more groups selected from substituent group d, a C1-C6 alkoxycarbonyl group optionally substituted by one or two or more groups selected from substituent group d, a heterocyclic group optionally substituted by one or two or more groups selected from substituent group d, a benzoyl group optionally substituted by one or two or more groups selected from substituent group d, and a benzyl group optionally substituted by one or two or more groups selected from substituent group d, wherein the substituent group d consists of a halogen atom, a carboxy group, an oxo group, an aminocarbonyl group, a C1-C6 alkoxy group, a C1-C6 alkoxycarbonyl group, a C1-C6 alkylaminocarbonyl group, a di-C1-C6 alkylaminocarbonyl group, a heterocycle-carbonyl group, a phenyl group, and a phenylaminocarbonyl group optionally substituted by one or two or more groups selected from substituent group e, wherein the substituent group e consists of a heterocycle-carbonyl group and a heterocycle-C1-C6 alkyl group.