Scale-up and Optimization of a Continuous Flow Synthesis of an α-Thio-β-chloroacrylamide

Use of continuous flow processing to undertake a multistep chlorination cascade has been achieved with effective inline workup and end-of-line crystallization in batch, leading to isolation of α-thio-β-chloroacrylamide Z-3 in pure form from a complex reaction mixture, exploiting the advantage of efficient heat transfer in flow. During development of a continuous flow strategy for production of appreciable quantities of α-thio-β-chloroacrylamides, difficulties surrounding a labor and resource intensive workup followed by final product isolation were addressed. A greener solvent choice was applied to the chemical synthesis, which enabled inline purification and separation, resulting in the crystallization of pure product directly from the reaction mixture. This process was readily scalable and demonstrated control over impurity formation and removal, which is key in an industrial setting.