Crystal structure of 1-ethyl-pyrazolo[3,4-d]pyrimidine-4(5H)-thione.

In the title compound, C7H8N4S, the methyl C atom is displaced by 1.232 (7) Šfrom the mean plane of the pyrazolo-[3,4-d]pyrimidine ring system (r.m.s. deviation = 0.007 Å). The N-N-C-Cm (m = meth-yl) torsion angle is -60.3 (6)°. In the crystal, mol-ecules are linked by N-H⋯S hydrogen bonds, generating [010] chains, which are reinforced by C-H⋯N inter-actions. The chains are cross-linked by weak C-H⋯S hydrogen bonds, generating (001) sheets.

Crystal structure of 4-allyl-sulfanyl-1H-pyrazolo-[3,4-d]pyrimidine.

In the title compound, C8H8N4S, the pyrazolo-[3,4-d]pyrimidine ring system is essentially planar, with a maximum deviation from the mean plane of 0.025 (3) Å. The allyl group is disordered over two sites in a 0.512 (6):0.488 (6) ratio. In the crystal, mol-ecules are linked by pairs of N-H⋯N hydrogen bonds, forming inversion dimers with an R 2 (2)(8) graph-set motif.

(2Z)-2-Benzyl-idene-4-n-butyl-3,4-di-hydro-2H-1,4-benzo-thia-zin-3-one.

In the title compound, C19H19NOS, the six-membered hetero-cyclic ring of the benzo-thia-zine fragment exhibits a screw boat conformation. The plane of the fused benzene ring makes a dihedral angle of 72.38 (12)° with that of the terminal phenyl ring, and is nearly perpendicular to the mean plane formed by the atoms through the n-butyl chain, as indicated by the dihedral angle of 88.1 (2)°. In the crystal, mol-ecules are linked by C-H⋯O inter-actions to form supra-molecular chains along [110].

Crystal structure of 1-methyl-4-methyl-sulfanyl-1H-pyrazolo-[3,4-d]pyrimidine.

In the title compound, C7H8N4S, the non-H atoms of the pyrazolo-[3,4-d]pyrimidine ring system and the methyl-sulfanyl group lie on a crystallographic mirror plane. In the crystal, mol-ecules are linked via a number of π-π inter-actions [centroid-centroid distances vary from 3.452 (7) to 3.6062 (8) Å], forming a three-dimensional structure.

4-[(1-Benzyl-1,2,3-triazol-5-yl)meth-yl]-2H-1,4-benzo-thia-zin-3(4H)-one.

The asymmetric unit of the title compound, C18H16N4OS, contains two independent mol-ecules of similar conformation, the most relevant difference being the dihedral angle formed by the benzene rings [57.8 (2) and 52.7 (2)°]. The six-membered heterocycle of the benzo-thia-zine fragment exhibits a screw-boat conformation in both mol-ecules. The plane through the triazole ring is nearly perpendicular to those through the fused and terminal benzene rings [dihedral angles of 74.2 (2) and 83.2 (2)° in one mol-ecule, and 77.8 (2) and 82.9 (2)° in the other]. In the crystal, mol-ecules are linked by C-H⋯N and C-H⋯O hydrogen bonds into chains parallel to the a-axis direction. The crystal used was a non-merohedral twin, the refined ratio of twin components being 0.85 (10):15 (10).

4-Benzyl-sulfanyl-1H-pyrazolo-[3,4-d]pyrimidine.

The pyrazolo-[3,4-d]pyrimidine ring system of the title compound, C12H10N4S, is essentially planar [maximum deviation = 0.025 (1) Šfor the C atom bearing the S atom] and almost perpendicular to the phenyl ring [dihedral angle = 71.42 (6)°]. In the crystal, mol-ecules are linked via pairs of N-H⋯N hydrogen bonds, forming inversion dimers.

Crystal structure of 1,5-diethyl-3',5'-di-phenyl-1,5-di-hydro-3'H-spiro-[pyra-zolo[3,4-d]pyrimidine-4,2'-[1,3,4]thia-diazole].

In the title compound, C22H22N6S, the pyrazolo-[3,4-d]pyrimidine rings system is almost planar, with the r.m.s. deviation for the fitted atoms being 0.011 Å. The two phenyl groups linked to the thia-diazole ring are nearly perpendicular to the fused-ring system as indicated by the dihedral angles of 86.93 (10) and 83.35 (11)°. However, the phenyl rings are almost coplanar with the thia-diazole ring (r.m.s. deviation = 0.015 Å), forming dihedral angles of 10.44 (11) and 10.06 (12)°. In the crystal, mol-ecules are connected into a supra-molecular layer in the ac plane via C-H⋯π inter-actions.

The crystal structure of 1,5-dibenzyl-1H-pyrazolo-[3,4-d]pyrimidine-4(5H)-thione.

In the title compound, C19H16N4S, the pyrazolo-[3,4-d]pyrimidine ring is close to being planar, with the greatest deviation from the mean plane being 0.023 (2) Šfor the C atom bearing the thione S atom. The two phenyl rings are nearly perpendicular to the fused ring system [dihedral angles = 71.4 (2) and 78.1 (2)°], but are oriented in opposite directions; the dihedral angle between the phenyl rings is 32.22 (16)°. In the crystal, linear supra-molecular chains along [101] are sustained by C-H⋯S inter-actions.