alpha , alpha -dichloroketones, process for their preparation and their use

摘要

The invention relates to a process for the preparation of alpha , alpha -dichloroketones of the formula I <IMAGE> in which R1 is an alkyl radical having up to 10 C atoms, an aralkyl radical having 7-12 C atoms, an aromatic radical having 6-14 C atoms or a heteroaromatic radical and R2 denotes the radicals Cl, CO-CCl3, CO-CF3, CF3, CN, COOR1, COR1, Si(R1)3 or R1, characterised in that carboxylic acids or activated derivatives thereof, of the formula II R1-CO-R4 in which R1 has the abovementioned meaning and R4 denotes the radicals OH, Cl, Br, F or OCOR1, are reacted with trichloromethyl compounds of the formula III Cl3C-R2 in which R2 has the abovementioned meaning, in the presence of phosphorus compounds of the formula IV P(R3)3 in which R3 denotes the radicals R1, OR1 or <IMAGE> and to the compounds of the formula I.p