Separation of α-cyano-3-phenoxybenzyl alcohol from α-cyano-3-phenoxybenzyl acetate using solvent extraction

Separation of α-cyano-3-phenoxybenzyl alcohol (CPBA) from α-cyano-3-phenoxybenzyl acetate (CPBAc) by solvent extraction was investigated. The effects of the species and volume ratio of solvents on the distribution coefficients and solubility of CPBA and CPBAc in several extraction systems were also studied. Furthermore, effects of pH of aqueous phase and temperature on the stability of CPBA were determined. Through screening, water:methanol:n-hexane:benzene = 3:7:7:3 (volume ratio) was selected as the optimal extraction system to separate CPBA from CPBAc. At 25 °C, after five extraction stages, the purity of CPBAc in the organic enriched upper phase was 95.2% (mol) and the yield reached 80.6%. And the purity of CPBA in the aqueous enriched lower phase was 98.8% (mol) and the yield reached 62.6%.