organic compounds
Open access
The title compound, C7H11N3O2S, exists in the 5-thioxo tautomeric form. The 1,2,4-triazoline ring is essentially planar, with a maximum deviation of 0.010 (2) Å for the substituted N atom. The ethyl acetate substituent is almost planar, with a maximum deviation of 0.061 (4) Å for the methylene C atom of the ethoxy group. The angle between the mean plane of this substituent and the mean plane of the 1,2,4-triazoline ring is 89.74 (8)°. In the crystal, molecules are linked by a combination of N—HS, C—HN and C—HO hydrogen bonds into chains parallel to [100].
organic compounds
Open access
The title compound, C21H16N4, obtained under standard Suzuki cross-coupling conditions, is a model compound in the synthesis and biological activity evaluation of new aza-analogues of sildenafil containing a pyrazolo[4,3-e][1,2,4]triazine system. An N—HN intramolecular hydrogen bond involving the aminobenzene system and the 1,2,4-triazine moiety helps to establish a near coplanar orientation of the rings with a dihedral angle of 12.04 (4)°, which is believed to be necessary for the biological activity of sildenafil analogues. The 1,2,4-triazine ring is slightly distorted from planarity [r.m.s deviation = 0.0299 (11) Å] and forms dihedral angles of 58.60 (4) and 36.35 (3)° with the pendant phenyl rings. The crystal packing features bifurcated N—H(N,N) hydrogen bonds linking screw-axis-related molecules into chains parallel to the [010] direction and π–π interactions, with a centroid–centroid separation of 3.8722 (7) Å and a slippage of 1.412 (3) Å. The crystal studied was a nonmerohedral twin with a ratio of 0.707 (2):0293 (2).