Reactions of thioketones. Part II. Thio-ozonide formation in some nucleophilic reactions of thioketones with amines and with benzenethiol

Thiobenzophenone (5) and thioadamantanone (15) have been shown to react with certain amines under ambient conditions to give low yields of the thio-ozonides 3,3,5,5-tetraphenyl-1,2,4-trithiolan (1) and dispiro[adamantane-2, 3'-(1,2,4-trithiolan)-5',2?-adamantane] (16) respectively. Reaction of (5) with benzenethiol also gave the thio-ozonide (1), whereas (15) gave 2,2'-bi-2-phenylthioadamantyl disulphide (21). Aminosulphuric acid reacted with (5) in the presence of base to give benzophenone oxime and (1). Parallel reactions with aliphatic thiones gave mainly the oximes. Mechanisms are proposed to account for the formation of the thio-ozonides. Initial nucleophilic attack on the thione affords a tetrahedral intermediate which is oxidatively dimerized to an unstable disulphide. Possible intermediates leading to the thio-ozonides are suggested.