An Expedient Approach to the Synthesis of Chloroacetic, Dichloroacetic and Acetic Acid Catalyzed by Sulfuric Acid in the Presence of Crown Ethers

Chloroacetic (1a), dichloroacetic (2a) and acetic acid (3a) were prepared by direct transformation of trichloroethylene, tetrachloroethylene and 1,1-dichloroethylene, respectively, using sulfuric acid in the presence of catalytic amounts of crown ethers. The newly developed method increases the reaction rate by suppressing the formation of by-products, and 1a, 2a and 3a were obtained in good yields at decreasedreaction temperatures and concentrations of sulfuric acid compared to conventional methods.