Solvent-free synthesis of triazines using N-halosulfonamides

l In this study, N, N, N', N'-tetrabromobenzene-1,3-disulfonamide and poly(N-bromo-N-ethylbenzene-1,3-disulfonamide) were used as efficient catalysts for the one-pot synthesis of 3,5,6-trisubstituted-1,2,4-triazines from readily available acid hydrazides, ammonium acetate and dicarbonyl compounds at 100 degrees C in good to excellent yields under solvent-free conditions.