THERMAL CROSS-COUPLED DIMERIZATION OF SODIUM ACRYLATE CROTONATE AND METHACRYLATE CROTONATE BINARY-SYSTEMS IN THE SOLID-STATE

The solid state thermal reactions of binary crystals obtained from an equimolar mixture solution of either sodium acrylate/crotonate Na(AA/CA) or sodium methacrylate/crotonate Na(MA/CA) give cross-coupled dimers. The main product obtained in a 51.4% yield from Na(AA/CA) on heating at 250-degrees-C for 2 h is, after conversion to a methyl ester, dimethyl pent-l-ene-3,4-dicarboxylate, and that from Na(MA/CA) obtained in a 41.7% yield on heating at 230-degrees-C for 2 h was dimethyl hex-1-ene-2,4-dicarboxylate. In either case, X-ray diffraction analysis of the mixed sodium salts shows a new phase different from that of the individual salt. As dimerization proceeds, a solid solution is formed, resulting in a high selectivity of dimer formation.