A method for the production of dichloroacetaldehyde with a significantly reduced content of monochloroacetaldehyde.

摘要

Dichloracetaldehyde is made by reacting acetaldehyde or a cyclic polymer thereof, preferably paraldehyde, with chlorine in the presence of 0.5 to 2.0% by weight of benzene sulphonic acid, toluene sulphonic acid or methane sulphonic acid, as catalyst and preferably containing up to 0.5% antimony trichloride as co-catalyst. It is preferred to carry out the chlorination in two stages, the catalyst being present in either or both stages. In the examples, a first stage chlorination product comprising dichloracetaldehyde, monochloracetaldehyde and a trace of chloral is chlorinated in the presence of the catalyst systems as above and for comparison in the absence thereof.