Synthesis of Chromeno[4′,3′:4,5]pyrido[1,2-a]pyrazines and -diazepines by the Reaction of Substituted 2-(3-Acetyl-2-oxo-2H-chromen-4-yl)fumarates with 1,n-Diamines

Abstract

A two-step sequence was developed for the synthesis of chromeno[4′,3′:4,5]pyrido[1,2-a]pyrazine-13-carboxylates and -diazepine-14-carboxylates by the reaction of substituted dimethyl 2-(3-acetyl-2-oxo-2H-chromen-4-yl)fumarates with 1,n-diamines at room temperature. Advantages of this protocol include ease of handling and the absence of a metal catalyst.