3-Mercapto-1,2,4 benzotriazine (1) was methylated by methyl iodide in the
presence of base to afford 1,2-dihydro-3-methyhercapto-1, 2,4 benzotriazine (2).
The latter was reacted with hydrazine hydrate to give the corresponding 3-hydrazine
derivative (3). Compound (3) on condensation with phenacyl bromide gave 3-
phenacyl hydrazino l,2,4-benzotriazine (4). PPA cyclization of the ketone (4)
yielded lH, 2H, 10H-4-phenyl-triazino [3,4-c]- 1,2,4-benzotriazine (5). Triazino
benzotriazine (5) is a novel heterocyclic system and is reported for the first time.