Provided are a compound indicated by formula (I), a pharmaceutically acceptable salt thereof, or a drug or pharmaceutical composition containing these as an effective component thereof, said compound having excellent xanthine oxidase inhibitory activity and effective as a treatment agent or prophylactic agent for diseases related to xanthine oxidase, such as gout, hyperuricemia, tumor lysis syndrome, urinary tract stones, hypertension, dyslipidemia, diabetes, cardiovascular diseases such as arterial sclerosis and heart failure, renal diseases such as diabetic nephropathy etc., respiratory diseases such as chronic obstructive pulmonary disease etc., and autoimmune diseases such as inflammatory bowel disease, etc.本發明係提供具有優良的黃嘌呤氧化酶抑制活性，且有用於作為痛風、高尿酸血症、腫瘤溶解症候群、尿路結石、高血壓症、脂質異常症、糖尿病、動脈硬化症或心臟衰竭等之心血管疾病、糖尿病腎病變等之腎疾病、慢性阻塞性肺疾病等之呼吸器疾病、發炎性腸疾病或自體免疫性疾病等的黃嘌呤氧化酶相關之疾病的治療藥或預防藥之式(I)表示之化合物或其製藥學上容許之鹽、或含有該等作為有效成分之醫藥或醫藥組成物。
