1129-52-8

Trichloroparaldehyde [1129-52-8] 2,4,6- tris (chloromethyl)-1,3,5-trioxane, C6H9Cl3O3, M_r 235.50, mp 88–89℃, bp 140–144℃(1.3 kPa), colorless crystals, soluble in common organic solvents, can be recrystallized from ethanol and forms monochloroacetaldehyde on heating in the presence of acids, e.g., oxalic acid.

Trichloroparaldehyde is formed by the reaction of concentrated sulfuric acid with the hemihydrate of monochloroacetaldehyde and is also part of the residue (with tetrachlorometaldehyde) left by azeotropic distillation of the hemihydrate. Trichloroparaldehyde can also be obtained by decomposing 1,2-dichloroethyl nitrate in the presence of Lewis acids, such as tin tetrachloride.