METHOD OF ISOLATION OF DICHLOROACETIC ACID Russian patent published in 1997 - IPC

FIELD: chemical technology. SUBSTANCE: method involves the use of an aqueous solution containing dichloroacetic acid, mono- and trichloroacetic acids. Solution is treated with strong base anionite at 95-125 C at water content in solution 10-20 wt. -% followed by treatment with a mixture of chlorohydrocarbon solvent (chloroform or carbon tetrachloride) with sulfuric acid. Mixture is settled, upper layer is separated and chlorohydrocarbon solvent is distilled off from its under atmospheric pressure. Dichloroacetic acid is isolated from a residue by vacuum rectification. Purity of product is above 99% If necessary, treatment with a mixture of solvent with sulfuric acid can be repeated and purity of dichloroacetic acid is 99.75%. The end product is used for production of chemical fibers and drugs. EFFECT: improved method of isolation, high purity of product. 4 cl, 4 tbl