Two-step syntheses of 3-methyl and 3-phenyl-1,2,4-benzotriazines

3-Methyl-1,2,4-benzotriazine and some of its derivatives were prepared in moderate yields (50–70%) via a reductive cyclization by a PtO2-catalyzed hydrogenation of the corresponding 2-nitrophenylhydrazones of the pyruvic acid. The latter compounds were obtained in yields higher than 90% by reacting 2-nitrophenylhydrazines with sodium pyruvate salt. Three 3-phenyl-1,2,4-benzotriazine compounds were also produced via a reductive cyclization by a Pt/C-catalyzed hydrogenation of their corresponding 2-nitrophenylhydrazono-ethers in high yields (>70%).