Kinetic study on reactive extraction of phenylalanine enantiomers with BINAP–copper complexes

Enantioselective liquid–liquid extraction has attracted considerable attention for its potential use in large-scale production. Kinetic data are needed for the reliable scale-up of the process. This paper reports the kinetic study of reactive extraction of phenylalanine (Phe) enantiomers with BINAP–copper complex (BINAP–Cu) as a chiral selector. The theory of extraction accompanied by a chemical reaction was applied. The effects of agitation speed, interfacial area, pH value of aqueous phase, initial concentration of Phe enantiomers and initial concentration of BINAP–Cu on the specific rate of extraction were investigated. The forward rate constants of the reactions in the reactive extraction process are 7.93 × 10− 5 m5/2·mol− 1/2·s− 1 for D-Phe and 1.29 × 10− 4 m5/2·mol− 1/2·s− 1 for L-Phe.

Graphical abstractD-Phe concentration in organic phase versus time at different agitation speeds. The increase is more quick when the agitation speed is higher. The equilibrium time decreases with the increase of agitation speed. The initial extraction rates at different agitation speeds is obtained from the slopes of the curves at t = 0.Figure optionsDownload full-size imageDownload as PowerPoint slide