Synthesis of imidazo[1,2-a][1,3,5]triazines by NBS-mediated coupling of 2-amino-1,3,5-triazines with 1,3-dicarbonyl compounds

Aroylimidazo[1,2-a][1,3,5]triazines are rapidly synthesized via a facile and mild reaction of 2-amino-triazines and 1,3-dicarbonyl compounds using NBS. The reaction occurred with good yields and excellent regioselectivity, and β-keto esters, β-keto amides, and 1,3-diones were tolerated under the optimized procedure. In addition, the successful application of this methodology for a gram-scale reaction indicates its potential for bulk synthesis.