Open-chain nitrogen compounds. Part IX. 1,2,3-Triazolo[1,5-a]quinazoline and its 5-alkyl and 5-aryl derivatives from alumina-catalysed cyclization of 1-(2′-acylphenyl)-3-cyanomethyltriazene

Alumina-catalysed cyclization of a series of 1-(2′-acylphenyl)-3-cyanomethyltriazenes ( 5 ) affords good yields of the previously unreported 5-alkyl- and 5-aryl-1,2,3-triazolo[1,5-a]quinazolines ( 8 ). The parent heterocycle, 1,2,3-triazolo[1,5-a]quinazoline, has been observed for the first time as the product of cyclization of 1-(2′-formylphenyl)-3-cyanomethyltriazene.