One-pot four-component synthesis of highly substituted [1,2,4]triazolo[1,5-a]pyrimidines

A green one-pot four-component strategy has been developed for the synthesis of [1,2,4]triazolo[1,5- a ]pyrimidine-6-carboxamide derivatives using an amine, 2,2,6-trimethyl-4 H -1,3-dioxin-4-one, an aldehyde, and 3-amino-1,2,4-triazole in the presence of a catalytic amount of p -toluenesulfonic acid in water within 4–6 h.