Dichloroacetaldehyde is a chlorinated aldehyde with the chemical formula . Along with monochloroacetaldehyde and trichloroacetaldehyde, it is one of the three possible chlorinated acetaldehydes.
Dichloroacetaldehyde is a highly volatile liquid that is easily soluble in water to form Hydrates. A geminal diol, also known as monohydrate, 2,2-dichloro-1,1-ethanediol, is formed in water.
The compound decomposes when heated. In the presence of Lewis acids such as antimony trichloride, iron(III) chloride, aluminum trichloride, tin(IV) chloride or boron trifluoride, the trimer hexachloroparaldehyde (2,4,6-tris(dichloromethyl)-1,3,5-trioxane) can be obtained. The trimer forms colourless crystals that melt at 131–132 °C. At the boiling point of 210–220 °C, dichloroacetaldehyde decomposes.
Reduction with lithium aluminium hydride gives dichloroethanol.[1]
Dichloroacetaldehyde is used to produce other chemical compounds such as mitotane.[2] Condensation with chlorobenzene yields p,p′-dichloro-1,1-diphenyl-2,2-dichloroethane, which was previously used as an insecticide:
Dichloroacetaldehyde can be obtained by chlorinating acetaldehyde or paraldehyde. Hypochlorination of 1,2-dichloroethylene using chlorine and water produces pure dichloroacetaldehyde.[3]