Continuous flow synthesis of β-amino α, β-unsaturated esters in aqueous medium

Abstract

Continuous flow synthesis of many β-amino α, β-unsaturated esters has been demonstrated, through the reaction of a β-ketoester compound with ammonia and primary amines. Several combinations have been studied in detail in batch mode and a few have been taken for continuous flow synthesis based on their suitability. Upon studying the feasibility of continuous flow synthesis of different β-amino crotonates, the synthesis of methyl amino crotonate in the presence of a recyclable and reusable homogeneous acid catalyst has been studied in detail. Tubular reactors were seen to overcome the heat and mass transfer limitations, thereby providing a simple device for even a pilot scale production. A similar approach can be used for the synthesis of other β-amino crotonates. The continuous flow synthesis approach for producing methyl amino crotonate, in the absence of any external solvent, makes it a green process technology.