PROCESS FOR THE PREPARATION OF CHLORIDES OF CHLORINATED CARBOXYLIC ACIDS

摘要

The invention relates to a process for the preparation of chlorides of chlorinated carboxylic acids of formula <IMAGE> in which R2 denotes the radical (CH2)n, n being an integer from 2 to 4, or the radical -CH2-C(C6H5)2- and R1 denotes a hydrogen atom or an alkyl radical containing from 1 to 4 carbon atoms, which consists in reacting the lactones of formula <IMAGE> in which R1 and R2 have the above meanings, with phosgene at a temperature of 90 DEG to 180 DEG C., while employing as catalysts trisubstituted phosphine oxides or sulphides. The process according to the invention makes it possible to obtain chlorides of chlorinated carboxylic acids of high purity which exhibit an excellent stability to light and to heat and which are very useful as synthesis intermediates.