Mechanism of Chlorination Process: From Propanoic Acid to α -Chloropropanoic Acid and Byproducts Using Propanoic Anhydride as Catalyst

This article reports on findings regarding the mechanism of chlorination process. in this experiment,propanoic acid was chlorinated to α-chloropropanoic acid in a lab-scale glass tube reactor operating at 130°c. propanoic anhydride and concentrated sulfuric acid were,respectively,used as the catalyst and the promoter. this experiment adopted the dft method to calculate the activation energy of routes for the synthesis α-chloropropanoic acid,β-chloropropanoic acid,α,α-dichloropropanoic acid,and α,β-dichloropropanoic acid. the results showed that the main route of α-chloropropanoic acid was formed through an ionic mechanism when propanoic anhydride was used as the catalytic agent. activation energy of 1-propen-1-ol,1-chloro,which was formed from 1-prop-anol,1-chloro-,was the highest in the process of ionic mechanism. in addition,α,α-dichloropropanoic acid was formed via a consecutive ionic chlorination path from α-chloropropanoic acid. β-chloropropanoic acid was produced from propanoic acid through a chlorination radical mechanism. α,β-dichloropropanoic acid was formed via a consecutive radical chlorination path. © 2017 da xue et al.