A compound represented by general formula (1)a pharmaceutically acceptable salt thereof or a solvate thereof； wherein Ar represents an aryl group, or a 5- or 6-membered heteroaryl group containing a nitrogen atom, an oxygen atom or a sulfur atom； Y represents, for example, a hydrogen atom or a C1-C6 alkyl group； A represents a C1-C3 alkylene chain which may be substituted with two C1-C2 alkyl groups； X represents a hydrogen atom or a halogen atom； V represents an oxygen atom or a methylene chain； and R represents a group selected from the formulae below:
