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 R1represents a -CO-(CH2)n-COR2group (wherein n is an integer of 1 to 4, and R2is (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.本發明提供一種苯并氮呯化合物，其可長時間維持血中托伐普坦的濃度，以提供所欲之藥學效果。本發明之苯并氮呯化合物係以通式(1)表示其中R1代表一－CO－(CH2)n－COR2基團(其中n係1至4之整數，且R2係(2－1)一羥基基團；(2－2)一低級烷氧基基團，可擇地經一羥基基團、一低級烷醯基基團、一低級烷醯基氧基基團、一低級烷氧基羰基氧基基團、一環烷基氧基羰基氧基基團、或5－甲基－2－側氧基－1,3－二氧雜環戊烯－4－基所取代；或(2－3)一胺基基團，可擇地經一羥基－低級烷基基團取代)，或其之類似物。
