Provided are compounds having an excellent hypoglycemic action and a β cell- or pancreas-protecting action or a pharmaceutically acceptable salt thereof, and a pharmaceutical composition having an excellent therapeutic effect and/or prophylactic effect on type 1 diabetes, type 2 diabetes, and the like, which cause an increase in the blood sugar level due to abnormal sugar metabolism. A compound represented by general formula (I), or a pharmaceutically acceptable salt thereof, is disclosed.