Synthesis and structure elucidation of new thiazolotriazepines

Article abstract of DOI:10.1016/S0040-4020(99)00253-7

The reaction of 1,2,4-triazepine-3-thiones (13) with 2-haloketones afforded thiazolo[3,2-b][1,2,4]triazepines (14) selectively. The same bicycles were obtained by reaction of the chalcones 11 with 3-amino-2-imino- 4-R-thiazolines. On the other hand, condensation of the chalcones 11 with 2- hydrazino-4-R-thiazoles led to the hydrazones 17 which upon treatment with acid underwent ring closure to yield the non-condensed bicyclic isomers of 14 i.e. the dihydropyrazolyl thiazoles 18. The elucidation of structures and stereochemistry was achieved by comprehensive one- and two-dimensional NMR spectroscopy.