Synthesis of polychlorinated [14C]alkanes (PCA) of high specific activity

The synthesis of certain ¹⁴C-labelled polychlorinated alkanes is described. The compounds used as starting material were 1-¹⁴C]lauric acid, 1-¹⁴C]hexadecane and U-¹⁴C]palmitic acid. The carboxylic acids were reduced with lithium aluminium hydride. The alcohol obtained was treated with triphenylphosphine dichloride which gave the corresponding 1-chloroalkane. The chlorination of the alkanes was performed in tetrachloromethane by use of sulphuryl chloride with benzoyl peroxide or UV-light as initiators. Three mixtures of polychlorinated dodecanes (45.9%, 55.9% and 68.5% chlorine) and two polychlorinated hexadecanes (34.1% and 69% chlorine) were synthesized. The products of higher chlorine content prepared were only available via the photoinduced chlorination.