The present invention provides a benzazepine compound that can maintain for a long period of time the blood level of tolvaptan enabling to provide the desired pharmaceutical effects. The benzazepine compound of the present invention is represented by general formula (1) wherein R1 represents a —CO—(CH2)n—COR2 group (wherein n is an integer of 1 to 4, and R2 is (2-1) a hydroxy group; (2-2) a lower alkoxy group optionally substituted with a hydroxy group, a lower alkanoyl group, a lower alkanoyloxy group, a lower alkoxycarbonyloxy group, a cycloalkyloxycarbonyloxy group, or 5 -methyl-2-oxo-1,3-dioxol-4-yl; or (2-3) an amino group optionally substituted with a hydroxy-lower alkyl group), or the like.