Symmetrical di:chlor-acetone continuous prodn. - by chlorinating aq. acetone in presence of iodine promoter, useful as crosslinking agent and intermediate for insecticides

摘要

Prodn. of 1,3-dichloroacetone (I) comprises reacting Cl2 with an aq. mixt. of acetone and/or monochloroacetone plus an iodide-contg. promoter (pref. ICl or a cpd. converted to ICl with Cl2). Pref. promoters are HI, alkali, alkaline earth, transition metal or NH4 iodides, methyl iodide iodoacetone, iodoacetic acid, diiodomethane or-ethane, I2 or ICl3. The reaction mixt. is passed to a liq. phase separator, giving an upper aq. phase for recycle plus a lower (I)-contg. phase. This is distilled to remove starting materials and (I) is recovered from the residue by crystallisation. (I) is a crosslinking agent for polymers and wood pulp, and an intermediate for germicides, fungicides and insecticides. There is improved yield and selectivity for (I), with (I): 1,1-dichloroacetone ratio generally >4:1, sometimes 15-20:1.