Abstract
1, 2-Diaminopyridinium mesitylenesulfonate (I) reacts, in the presence of potassium carbonate, with a variety of α, β-unsaturated carbonyl compounds such as benzoylacetyllenes, benzalacetophenones, ethoxymethylenepentane-2, 4-dione, and diethyl ethoxymethylenemalonate to give s-triazolo[1, 5-a]pyridine derivatives, presumably via 1-amino-2-imino-1, 2-dihydropyridine (VIII). Reaction of I with diphenylcyclopropenone in ethanol in the presence of potassium carbonate afforded ethyl 3-amino-2, 3-diphenylacrylate, whereas reaction of VIII in an aprotic solvent (benzene) gave 3-amino-2, 3-diphenyl-N-(2-pyridyl)acrylamide.
