Preparation of alpha chlorinated carbonyl compound comprises decarboxylating an alpha-chlorinated beta-ketoester compound in an aqueous medium in the presence of a base at a mild basic pH

摘要

Preparation of alpha chlorinated carbonyl compound comprises decarboxylating an alpha-chlorinated beta-ketoester compound in an aqueous medium and in the presence of a base at a pH of 8-9. Preparation of alpha chlorinated carbonyl of formula (R1-C(O)-C(Cl)-R2) comprises decarboxylating an alpha-chlorinated beta-ketoester compound of formula (R1-C(O)-C(R2)(Cl)-C(O)-OR3) in an aqueous medium in the presence of a base at a pH of 8-9. R1 : alkyl, aralkyl or aryl, where the CH2 group is optionally substituted by hetero atoms such as -NH, -NCH3, -S or -O- and the CH group is optionally substituted by -N=, when the alkyl, aralkyl or aryl is optionally further substituted with functional groups such as halo, amino, alkylamino, dialkylamino, alkoxy, carbonyl, alkoxycarbonyl, thioalkyl or trialkysilyl; R2 : H, alkyl, aralkyl or aryl, chlorine or bromine; and R3 : alkyl or silyl.