Open chain nitrogen compounds. Part XIII. 1-Aryl-3-arylthiomethyl-3-methyltriazenes and 3-(arylazo)-1,3-thiazolidines

Reaction of 3-acetoxymethyl-1-aryl-3-methyltriazenes with sodium thiophenolate or thiocresolate in anhydrous dimethylformamide affords a new series of 3-arylthiomethyltriazenes (2), Ar-S-CH2-NMe-N=N-Ar′. These triazenes are remarkably labile in aqueous buffer and may be good pro-drugs for the active metabolite of the antitumour dimethyltriazenes. The reaction of arenediazonium fluoroborates with 1,3-thiazolidine in aqueous acetone affords a new series of N-arylazo-1,3-thiazolidines (4); the arylazothiazolidines represent a new class of triazene in which the N3 nitrogen is incorporated into a heterocyclic unit, in this case a 1,3-thiazolidine. Nuclear magnetic resonance spectra of the arylazothiazolidines show evidence for rotational isomerism of the exocyclic N2—N3 bond in the triazene moiety.