In the homologous series of p-chlorophenyl ω-chloroalkyl sulphides (I), the first and second members reacted abnormally with amines to yield 1, ω-bis(p-chlorophenylmercapto)alkanes (II). The fourth member of the series reacted normally to produce 4-aminobutyl p-chlorophenyl sulphide (III). The formation of II is explained on the basis of an alkyl–sulphur bond cleavage. The members of the p-chlorobenzyl series (VI) in general reacted with amines to form the expected aminoalkyl sulphides (VII). However, the p-chlorobenzyl chloroalkyl sulphides (VI) were thermally labile and decomposed to p-chlorobenzyl chloride and a sulphur component. A cyclic sulphur component originated from VI whose chloroalkyl carbon chain was 4, 5, or 6. The thermal degradation of VI is explained through a sulphonium salt cleavage
7-Chloro-2,3-dihydrobenzo(f)-l,4-dithiepin (IV) has been synthesized from 2-(2-chloro-ethylmercapto)-5-chlorobenzyl chloride (I). Attempts to synthesize the higher homologues of IV by this method failed because the required intermediates cleaved at the alkyl–sulphur bond. A reaction product of p-chlorothiophenol, formaldehyde, and hydrogen chloride has been identified as 2,8-dichloro-6H,12H-dibenzo(b,f)-l,5-dithiocin (VI), a tricyclic system with the eight-membered ring containing two sulphur atoms.