A PROCESS FOR THE PREPARATION OF 1,1-BIS(4-CHLOROPHENYL)-2,2,2-TRICHLOROETHANOL

摘要

Disclosed is a process for the preparation of1,1-bis(4-chlorophenyl)-2,2,2-trichloroethanol (known as p,p'-dicofol), starting out from a mixture containing thiscompound, i.e. 1,1-bis(4-chlorophenyl)-2,2,2-trichloro-ethanol, in admixture with at least one compound selectedfrom the group consisting of 1-(4-chlorophenyl)-1-(2-chloro-phenyl)-2,2,2-trichloroethanol (known as o,p'-dicofol);1-(4-chlorophenyl)-1-(2-chlorophenyl)-2,2,2-trichloroethane(known as o,p'-DDT); and 1-(4-chlorophenyl)-1-(2-chloro-phenyl)-2,2-dichloroethylene (known as o,p'-DDE). Thisprocess which permits to separate biologically activep,p'-dicofol in large yield from raw dicofol, basically comprisesthe formation of an addition compound between 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethanol and a second moderatelyelectron donating compound, such as a hydroxylatedsubstance, an ether, a ketone, a carboxylic acid, asulphoxide and a nitrogenated derivative; the isolation ofthe addition compound being formed; and the subsequentdecomposition of the addition compound to recover thedesired compound.