ChemInform Abstract: Heterocyclic Systems Containing Bridgehead Nitrogen Atom: Part 57. Syntheses of 2,5-Disubstituted Thiazolo(3,2-b)-s-triazoles and 3,5-Disubstituted Thiazolo(2,3-c)-s-triazoles.

ChemInform Abstract

Starting from the thiosemicarbazides (I) the ketones (IV) are prepared via the triazoles (II). In part, they are isolated as hydrobromides. Cyclization of (IV) gives the 2,5-disubstituted title compounds (V) which alternatively can be obtained directly from (II) when MeOH is used instead of EtOH. The fact that (V) is formed in the cyclization process of (IV) is confirmed by unambiguous synthesis of the isomers (VII) and results from spectral data.