A compound represented by the general formula (1) below or a pharmacologically acceptable salt thereof :[In the formula (1),R1 and R2 may be the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, an optionally substituted C1-6 alkyl group et al.； R3 represents a hydrogen atom； R4 represents an optionally substituted 4- to 10-membered monocyclic heterocyclic group containing 1 to 4 heteroatoms selected from an oxygen atom, a nitrogen atom, and a sulfur atom； X represents a group represented by the following formula: -CH2-, - CH2-CH2-, -CH2-CH2-CH2-, or -CH2-O-CH2-； and Z represents a hydrogen atom or a hydroxyl group.]
