One objective of the present invention is to provide a compound having V2 receptor agonist effect. The pharmaceutical composition of this invention uses a compound expressed by the following general formula (I) or its pharmacologically acceptable salt as an active ingredient, wherein, R1 represents the following formula: wherein, A represents a lower alkylene group or the like which may be substituted with a lower alkyl group R6 represents a hydrogen atom or the like R7 represents a hydroxyl group, an aromatic heterocyclic group which may be substituted with a lower alkyl group, amine methyl acyl or the like R2 represents a hydrogen atom or a lower alkyl group R3 represents a lower alkyl group which may be substituted with 1 to 3 fluorine atoms or a halogen atom R4 represents 5-membered aromatic monocyclic heterocyclic group, or 5-membered non-aromatic monocyclic heterocyclic group or the like, wherein the heterocyclic group contains at least one nitrogen atom, and may be substituted with a lower alkyl group R 5 represents a lower alkyl group or a halogen atom or the like.本發明之課題在於提供一種具有V2受體促效作用之化合物。本發明之醫藥組合物係以下述通式(I)所表示之化合物或其藥理學上容許之鹽作為有效成分:[式中,R1表示下述式:(式中,A表示可經低級烷基取代之低級伸烷基等;R6表示氫原子等;R7表示羥基、可經低級烷基取代之芳香族雜環基、或胺甲醯基等)等;R2表示氫原子或低級烷基;R3表示可經1~3個氟原子取代之低級烷基、或鹵素原子;R4表示5員芳香族單環式雜環基、或5員非芳香族單環式雜環基等(其中,該等雜環基含有至少一個氮原子,且可經低級烷基取代);R5表示低級烷基或鹵素原子等]。