Patent ID: 6433224
Filing Date: 2002-08-13
Classification: C07C

Abstract:
A process for the preparation of acid chlorides by reaction of carboxylic acids, carboxylic anhydrides, cyclic carboxylic esters or sulfonic acids with phosgene in the presence of a catalytic amount of a compound from the group consisting of N,N,Nâ€²,Nâ€²-tetrasubstituted amidinium halides (I), N,N,Nâ€²-trisubstituted amidinium hydrohalides (II) and N,N,Nâ€²-trisubstituted amidines (III) of the formula in which the radicals R1, R2 and R4 are linear or branched alkyl chains having from 1 to 20 carbon atoms or cycloaliphatic radicals having a ring size of from 5 to 8 carbon atoms, where the rings can be interrupted by heteroatoms, or R1 and R2 are unsubstituted or substituted aromatic radicals or together form a chain of 4 or 5 methylene groups;R3 is a hydrogen atom or a branched or unbranched alkyl radical having from 1 to 6 carbon atoms or a cycloalkyl radical having from 3 to 6 carbon atoms and R1 in compound I is a branched or unbranched alkyl chain having from to 6 carbon atoms, and X is a halide.