Synthesis and molecular structure of 6-amino-3-benzylmercapto-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H)-one.

The title compound 6-amino-3-benzylmercapto-1,2,4-triazolo[3,4-f][1,2,4]-triazin-8(7H)-one (4), molecular formula C(11)H(10)N(6)OS, was obtained by the reaction of 3-amino-2-benzyl-6-hydrazino-1,2,4-triazin-5(2H)-one (3) with carbon disulfide in a water/pyridine mixture. Compound 4 can also be synthesized by reacting 6-amino-3(2H)mercapto-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H)-one (7) with benzyl bromide in methanolic ammonia water. The compound crystallizes in the monoclinic space group P2(1)/c with a = 7.2926(15), b = 14.456(2), c = 11.436(2) A, beta = 105.30(2) degrees , V= 1162.9(4) A(3) and Z = 4, resulting in a density Dcalc of 1.567 g/cm(3). Molecules of 4 are linked by extensive intermolecular N-H...N and N-H...O hydrogen bonding [graph set R(2)(2 )(9)]. The structure is further stabilized by pi-pi stacking interactions.