Improvements in or relating to trichloroacetic acid, esters of trichloroacetic acid and salts of trichloroacetic acid

摘要

A mixture containing 15-75 per cent. glacial acetic acid and 85-25 acetic anhydride is chlorinated at a temperature of at least 70 DEG C. to approximately the trichloracetic acid stage. Chlorination to the monochlor stage is effective at 70-120 DEG C. and is continued at about 120-170, e.g. 150 DEG C. to about 90 per cent. trichloracetic acid or until addition of water in sufficient amount to hydrolyse the trichloracetyl chloride present yields a product having a crystallizing point above 51 DEG C. after removal of the HCl formed. The apparatus and conditions used for the chlorination are otherwise as described in the parent specification. The chlorination product may be esterified with an alcohol, e.g. mono- or poly-hydric, saturated or unsaturated, primary or secondary, aliphatic, aromatic or heterocyclic alcohols, of which many are specified, including substituted alcohols, e.g. ethoxy ethanol, 2-bromethanol, chlorhydrin and cyanohydrin, or may be converted to salts by reacting with an alkaline derivative of a salt forming group. Examples describe the chlorination of various mixtures of acetic acid and anhydride and the hydrolysis of impurities with water, neutralization with sodium, potassium, magnesium or calcium carbonate, sodium, lithium or ammonium hydroxide, potassium bicarbonate, methylamine or isopropanolamine to give salts or esterification with isopropyl, ethyl or benzyl alcohol, ethylene glycol, monobutyl ether, isopropoxy-propoxy-propanol, diethylene glycol or cyclohexanol.