The object of the present invention is to provide a compound having an antagonistic action against µ-opioid receptors, which causes less side effects and thus is highly safe. A compound represented by the general formula (I), or a pharmacologically acceptable salt thereof: wherein R 1 and R 2 are the same or different, and each represents a hydrogen atom or a halogen atom, provided that R 1 and R 2 are not simultaneously halogen atoms, R 3 represents a C 1 -C 3 alkyl group or a vinyl group, and R 4 represents the formula (II): wherein R 5 represents a hydroxy group or a C 1 -C 3 alkoxy group, and R 6 and R 7 are the same or different, and each represents a hydrogen atom or a halogen atom or the formula (III): wherein Ring A represents a halogen atom(s)-substituted C 5 -C 7 cycloalkyl group which is optionally substituted by a C 1 -C 3 alkoxy group, or a halogen atom(s)-substituted 5- to 7-membered saturated heterocyclic group.
