Effect of solvent on enantioselective esterification of naproxen by lipase with trimethylsilyl methanol

Improvement of stereoselective resolution of racemic Naproxen, 2‐(6‐methoxy‐2‐naphthyl)propionic acid, was attempted with esterifcation reaction by Candida cylindracea lipase. By carefully selecting the organic medium, a 72‐time enhancement of yield of the desired S‐ester was achieved. The optimal reaction temperature was approximately 53°C, and an alcohol concentration between 20 mM and 40 mM in an 80% (v/v) isooctane and 20% (v/v) toluene mixture was found. © 1994 John Wiley & Sons, Inc.