Process for the continuous preparation of 3-chlorobutanone

摘要

The invention relates to an improved process for the continuous preparation of 3-chlorobutanone by chlorination of butanone with copper(II) chloride in aqueous solution at temperatures up to the boiling point of the reaction mixture and regeneration of the used copper chloride by hydrogen chloride and oxygen or oxygen-containing gases. The chlorination is carried out using an aqueous copper(II) salt solution which, in addition to copper(II) chloride, contains copper(II) acetate in amounts such that altogether 0.01 to 0.3 mol of acetate ions are present per mol of copper. Butanone is employed in excess for the chlorination reaction and oxygen is employed in excess for the regeneration reaction, in each case relative to the hydrogen chloride necessary for the regeneration. The aqueous copper(II) salt solution is carried in a circulation to which butanone, hydrogen chloride and oxygen are continuously added and organic reaction products and a part of the used copper salt solution are removed. At a conversion of 60% of the butanone in the circulation, 3-chlorobutanone is obtained in yields of up to 90% of theory, relative to butanone used, and with a selectivity of > 96%. <IMAGE>