The present invention relates to provision of a novel compound that has an activity of promoting insulin secretion from pancreatic β cells and thus is useful as a prophylaxis and/or therapeutic agent for diseases caused by hyperglycemia such as diabetes mellitus, and the compound represented by the following formula (1):wherein one of A and B represents a nitrogen atom and the other represents a nitrogen atom or CR10, X represents an oxygen atom, a sulfur atom or - (CH2)n-N(R12) -, Y represents an oxygen atom, a sulfur atom or -N(R13)-, and R1 to R9 each represent a hydrogen atom or another substituent, or a salt thereof, or a solvate of the compound or the salt.
