Production of optically active ketoprofen by direct enzymatic esterification

For the production of optically active ketoprofen, enzymatic resolution of racemic ketoprofen in an organic solvent has been accomplished via enantios elective esterification. Pharmacologically inactive (R)-ketoprofen is conve rted into the corresponding (R)-ester by this method. Enantioselectivity in lipase-catalyzed resolution of racemic ketoprofen was mainly dependent on the sources of lipase, alcohol moiety, organic solvent, and water content. Ethanol was used as the alkyl donor and the optimum water content required for highly efficient enzymatic resolution was determined to be 0.1-0.15% (v /v), which was maintained using salt hydrates such as Na2SO4. 10H(2)O. (S)- Ketoprofen could be obtained with high anantioselectivity (E=15) in n-hexan e supplemented with ethylene dichloride (20% (v/v)) using commercially avai lable Candida antarctica lipase (Novozym(R)435).