An object of the present invention is to provide anovel low molecular weight compound exhibiting anosteogenesis-promoting action. This object is achievedby a compound having the general formula (I) or apharmacologically acceptable salt thereof:(see formula I)wherein each substituent is defined as follows: R1represents an alkyl group or the like; R2 represents analkyl group or the like; R3 represents a hydrogen atom orthe like; and Z represents -CH= or -N=.