Asymmetric synthesis of chiral amine in organic solvent and in-situ product recovery for process intensification: A case study

Membrane assisted extraction in a contactor, which allows for the separation of the reaction components between two immiscible liquid phases, was applied for transamination. The reaction was conducted in an organic solvent which resulted in two benefits: higher solubility of the poorly water soluble substrate benzyl acetone, and the possibility of product removal in an aqueous phase. The aqueous phase was circulated across the shell of a hollow fiber membrane module and the organic phase (n-heptane) through the lumen. Approaches to extract the product amine, 1-methyl-3-phenylpropylamine proved beneficial to reduce its inhibitory effects, while providing an equilibrium shift aiding in higher product formation. After 72 h of operation in membrane contactor, 99% substrate conversion was observed.