A simple and convenient synthesis of 3-salicyloylquinoline-4-carboxylic esters from chromone and isatin

Abstract

A simple and convenient synthesis of 3-salicyloylquinoline-4-carboxylic esters has been developed through an AlCl₃-catalyzed reaction of easily available Baylis–Hillman adducts from chromones and isatin-derivatives. This reaction involves esterification, cyclization and ring opening in a one-step process, and provides an efficient approach for easy access to a series of valuable salicyloylquinoline derivatives with high yields. Moreover, this protocol offers several advantages, such as availability of starting materials, economic availability, operational simplicity and mild reaction conditions.