PROBLEM TO BE SOLVED: To provide a new medicine by which promotion of osteogenesis can be expected. SOLUTION: This invention relates to a compound represented by the general formula (I), its acid addition salt or hydrate or an osteogenesis-promoting composition which are each effective in promoting osteogenesis. Since the compound represented by the general formula (I) increases mRNA of BMP-2, the compound is effective in promoting osteogenesis.