The GPR40 receptor function regulator of the present invention, which comprises a compound having an aromatic ring and a group capable of releasing cation is useful as an insulin secretagogue or an agent for the prophylaxis or treatment of diabetes and the like.
2-dioxazol-5-ones to form dihydroquinoline-2-ones in excellent yields with excellent regioselectivity via a formal intramolecular arene C(sp2)–Hamidation. The reactions of the 2- and 4-substituted aryl dioxazolones proceeds initially through spirolactamization via electrophilic amidation at the arene site, which is para or ortho to the substituent. A Hammett correlation study showed that the spirolactamization