Provided is a compound or a salt thereof having agonist activity for GPR52 and useful as a prophylactic or therapeutic medicine for psychiatric disorders such as schizophrenic disorder.(In the formula, the respective symbol has the same meaning as that defined in the specification.)本發明提供對GPR52具有促效活性且在做為精神分裂症等精神疾病等之預防/治療用醫藥上為有效之化合物或其鹽:(式中,各記號表示與說明書中相同之意義)。