A new synthesis for 1,3‐dichloro‐2‐propanone

A new synthesis for 1,3-dichloro-2-propanone (symm-dichloroacetone) is described using diketene and chlorine as starting materials. The chlorination product of diketene, 2,4-dichloro-3-oxobutyryl chloride, was converted into the corresponding butyric acid derivative. Subsequent decarboxylation by heating gave 1,3-dichloro-2-propanone in 77% overall yield, without isolation of intermediate products.