As it may be seen from Scheme 1, several products are formed by cycloaddition of compound II to substituted aromatic isothiocyanates I. The ring of the primary unstable adducts III and IVis opened with the formation of elemental sulfur, N-benzylideneaniline, N- phenylthiobenzamide, the corresponding substituted benzamidines, and 4-substituted 2, 3- diphenyl-1, 2, 4-oxadiazolidines. With the type III adducts, the NO bond appears to be ...
