Ion-exchange resin catalysis in the synthesis of isopropyl lactate

Isopropyl lactate is a very important pharmaceutical intermediate. The curr ent practice is to use homogeneous acids as catalysts. These catalysts are hazardous and disposal of liquid acid effluents poses problems. The separat ion of the liquid catalyst and its reuse is another problem. The current pa per deals with the application of heterogeneous catalysts Indion-130, Ambel yst-36, Amberlyst-15, Amberlite-120, Dowex 50W, Filtrol-44, 20% DTPA/K-10 ( dodecatungstophosphoric acid supported on K-10 clay) and 20% DTPA/Filtrol-4 4 (dodecatungstophosphoric acid supported on Filtrol-44 clay). Amongst thes e Amberlyst-36, Amberlyst-15 and Indion-130 were observed to be most effect ive. A theoretical kinetic model was developed fur evaluation of this slurr y reaction. The effects of various parameters on the rate of reaction were evaluated. The reaction was found to he intrinsically kinetically controlle d and there were no intraparticle as well as interparticle mass transfer li mitations on the rate of reaction. (C) 2000 Elsevier Science B.V. All right s reserved.