Investigation For Pilot-scale Hydroesterification Reaction Of Chiral Epichlorohydrin

In this paper,by investigating the influence of different ligands on the hydroesterification of epichlorohydrin in cobalt-based catalyst system,the reaction conditions and catalytic system with conversion > 99% and selectivity > 90% were obtained.The separation method of(S)-4-chloro-3-hydroxybutyrate from catalyst system was explored,and the homogeneous catalyst in reaction solution was separated and recycled.On the basis of pilot-scale conditions,200 L pilot-scale experiment of hydroesterification of epichlorohydrin was carried out.1.Co2(CO)8 was used as the main catalyst for the synthesis of ethyl(S)-4-chloro-3-hydroxybutyrate by hydrogenation of(S)-propylene oxide to ethyl(S)-4-chloro-3-hydroxybutyrate.The results showed that the conversion of hydroesterification of epichlorohydrin was more than 99%,the selectivity of the product was more than 90%,and the EE value of the product was more than 99%.The different ways of separating catalyst were tested.After three cycles of using solvent,catalyst and ligand separated from reaction liquid,the selectivity and conversion of reaction decreased by less than 10%.The cycles of catalyst and solvent were achieved,and the cost of reaction was effectively reduced,which laid a foundation for the industrialization of this process.2.Based on our previous pilot study on octocarbonyl dicarbonate,we carried out a pilot scale-up experiment in a 20 L reactor.After repeated experiments,the yield of octocarbonyl dicarbonate can be stabilized at 75%,and the purity of octocarbonyl dicarbonate is more than99%.Pilot-scale experiments were carried out on the hydroesterification of chiral epichlorohydrin.By comparing pilot-scale experiments with pilot-scale experiments,a series of adjustments were made to the reaction conditions of pilot-scale experiments.The conversion of epichlorohydrin was more than 99%,while the selectivity of products was more than 75%,EE value was more than 99%.The recyclable catalyst base liquor was obtained by flash evaporationand film evaporation,and the catalyst base liquor was recycled.After that,the conversion and selectivity of the reaction decreased slightly,but it accorded with the cyclic law of small-scale experiments,which proved the feasibility of industrial application of(S)-epichlorohydrin hydroesterification.