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 alpha-chloropropanoic acid in a lab-scale glass tube reactor operating at 130 degrees 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.. alpha-chloropropanoic acid,beta-chloropropanoic acid, alpha,alpha-dichloropropanoicacid, and alpha,beta-dichloropropanoic acid. The results showed that the main route of alpha-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 1prop-anol,1-chloro, was the highest in the process of ionic mechanism. In addition,alpha,alpha-dichloropropanoic acid was formed via a consecutive ionic chlorination path from alpha-chloropropanoic acid beta-Chloropropanoic acid was produced from propanoic acid through a chlorination radical mechanism. alpha,beta-Dichloropropanoic acid was formed via a consecutive radical chlorination path.