Organoiodine (III) Mediated One-Pot Synthesis of Several New Coumarinyl-Triazolo-TriazinesAuthor(s): Pundeer R and Kiran V
The study foregrounds the efficacy of organoiodine (III) reagent, [hydroxy(tosyloxy)iodo]benzene (PhI(OH)OTs) in the synthesis of new derivatives of coumarinyl containing N-bridgehead heterocyclic compounds namely, 3-aryl-6-(3-coumarinyl)-[1,2,4]triazolo[4,3-b][1,2,4] triazines (4) from the reaction of 3-(α-tosyloxyacetyl)coumarins (2) and 5-aryl-3,4-diamino-s-triazoles (3). The umpolung compounds 2 are, in turn, obtained by the α-tosyloxylation of 3-acetylcoumarins 1 with PhI(OH)OTs. The reaction was also carried out in one-pot starting from enolizable ketones 1 by generating the tosyloxyketones 2 in situ. In one-pot procedure, the ketones 1 are first treated with PhI(OH)OTs and then with diaminotriazoles 3 to furnish the expected title compounds 4 in better yields than the stepwise procedure.