PHASE-EQUILIBRIA WITH SUPERCRITICAL CARBON-DIOXIDE FOR THE ENZYMATIC PRODUCTION OF AN ENANTIOPURE PYRETHROID COMPONENT .2. TERNARY AND 5-COMPONENT SYSTEMS

(S)-alpha-Cyano-m-phenoxybenzyl alcohol is an important synthon for py rethroid insecticides. It is obtained by the lipase-catalyzed kinetic resolution of racemic alpha-cyano-m-phenoxybenzyl acetate, with 1-octa nol acting as an acyl acceptor and thus being converted to 1-octyl ace tate. Supercritical carbon dioxide is used as a unique solvent for the reaction and the subsequent product recovery by extraction. Phase equ ilibria of the ternary systems CO2 + alpha-cyano-m-phenoxybenzyl alcoh ol + alpha-cyano-m-phenoxybenzyl acetate and CO2 + 1-octanol + 1-octyl acetate were measured at 313.15 K and at respective pressures of 20 M Pa and 8 MPa. The latter ternary exhibits alyotropic behavior. Phase e quilibria of the ternary CO2 + 1-octanol + alpha-cyano-m-phenoxybenzyl acetate and the five-component system CO2 + 1-octanol + 1-octyl aceta te + alpha-cyano-m-phenoxybenzyl alcohol + alpha-cyano-m-phenoxybenzyl acetate were determined at 313.15 K and at various pressures of up to 17 MPa. The Soave-Redlich-Kwong equation of state with the mixing rul es due to Huron and Vidal was checked for its ability to reproduce the measured equilibrium data. Whereas model predictions match experiment al data of the ternary systems within the estimated accuracy of the me asurements, larger deviations exist for the five-component systems.