PROBLEM TO BE SOLVED: To provide a preventive and/or therapeutic agent for diabetic complications such as retinopathy, nephropathy, neuropathy and the like that exhibits a sufficient aldose reductase-inhibiting action.SOLUTION: There is provided a compound represented by formula (1) or a salt thereof, or a solvate thereof.COPYRIGHT: (C)2012,JPO&INPIT【課題】十分なアルドース還元酵素阻害作用を示す、網膜症、腎症、神経障害等の糖尿病合併症の予防及び/又は治療剤を提供する。【解決手段】式(1):で表される化合物若しくはその塩、又はそれらの溶媒和物。【選択図】なし