Synthesis of 1,2,4-Triazines; XIII. Regioselective Synthesis of Trialkyl-1,2,4-triazines

Trialkyl-1,2,4-triazines (3) were prepared by heating α-oxoacylhydrazones (4) or N,N-dimethylaminomethylene hydrazones (19) with ammonium acetate at 100°C. The solvent plays an important role in the regioselectivity of these reactions