화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.52, No.18, 6129-6137, 2013
Atom Economical Green Synthesis of Chloromethyl-1,3-dioxolanes from Epichlorohydrin Using Supported Heteropolyacids
Bioglycerol can be valorized to different products, among which epichlorohydrin is an important intermediate used in a variety of industries. Chloromethyl-1,3-dioxolane is one of the important pharmaceutical intermediates, which is obtained by cycloaddition reactions of epichlorohydrin with ketones. Chloromethyldioxolane derivatives are used as tranquilizers, as plasticizers, as a new class of adrenoceptor antagonists, and also as potential monomers for polymerization and ploycondensation. In the present work, study of the cycloaddition reaction of epichlorohydrin with acetone using 20% (w/w) cesium-substituted dodecatungstophosporic acid (Cs2.5H0.5PW12O40, Cs-DTP) supported on K10 clay has been done. Different catalysts such as K10 clay, 20% (w/w) dodecatungstophosporic acid (DTP)/K10, 20% (w/w) Cs2.5H0.5PW12O40/K10, and 20% (w/w) Cs2.5H0.5PW12O40/HMS were synthesized, and their efficacies were studied. The 20% (w/w) Cs2.5H0.5PW12O40 (Cs-DTP)/K10 clay was found to be highly active. The catalyst was well characterized by different techniques, viz., FTIR, XRD, SEM, and NH3-TPD. A temperature of 70 degrees C and mole ratio of epichlorohydrin to acetone of 1:8 should be used. The reaction is 100% atom economical and green. The catalyst is reusable. A kinetic model for the cycloaddition reaction has been developed. The reaction mechanism is of the Langmuir-Hinshelwood-Hougen-Watson (LHHW) type with very weak adsorption of both reactants in the absence of any diffusion resistance. The energy of activation is 15.77 kcal/mol.