Regioselective ring opening reaction of epichlorohydrin with acetic acid to 3-chloro-2-hydroxypropyl acetate over cesium modified heteropolyacid on clay support

Abstract

3-Chloro-2-hydroxypropyl acetate has wide applications in production of various epoxy resins, reactive polymers used for coating metal, leather, paper and wood. Regioselective ring opening reaction of epichlorohydrin with acetic acid to synthesize 3-chloro-2-hydroxypropyl acetate was studied using various solid acid catalysts such as 20% dodecatungstophosphoric acid (DTP)/K-10 clay, 20% (w/w) Cs_2.5H_0.5PW₁₂O₄₀/K-10, sulphated zirconia (SO₄/ZrO₂) and tungstated zirconia (WO₃/ZrO₂). Among the various screened catalysts, Cs_2.5H_0.5PW₁₂O₄₀ (Cs-DTP) supported on K-10 clay was found to be highly active and selective for regioselective ring opening of epichlorohydrin. The selectivity was >98%. The incorporation of Cs-DTP salt on K10 clay was found to increase acidity of catalyst as well showed change in structural properties which ultimately increased the selectivity of catalyst toward 3-chloro-2-hydroxypropyl acetate. Various parameters affecting the conversion and initial rates of reaction were optimized and a kinetic model was developed. The proposed kinetic model matches the experimental data very well.