Fused pyrimidine derivatives

摘要

A fused pyrimidine derivative is presented. The derivatie has an insulin secretion stimulating activity represented by Formula (I): {wherein R¹ represents a hydrogen atom, lower alkyl, or the like; n represents an integer of 0 to 3; and X¹ and X² may be the same or different and each represents a hydrogen atom, lower alkyl, or the like; and formula (II): represents formula (III): [wherein X-Y-Z represents R²C-CR³-NR⁴ (wherein R², R³ and R⁴ may be the same or different and each represents a hydrogen atom, lower alkyl, or the like)]}, or a pharmaceutically acceptable salt thereof.