No abstract

In the title pyrazole compound, C21H15N3O4, an intra­molecular C—H⋯O hydrogen bond generates an S(7) ring motif. The essentially planar furan and pyrazole rings [maximum atomic deviations of 0.011 (2) and 0.006 (2) Å, respectively] make a dihedral angle of 9.21 (11)°. The nitro group is approximately coplanar with the attached furan ring, as indicated by the dihedral angle of 4.5 (2)°. In the crystal structure, inter­molecular C—H⋯O inter­actions form bifurcated hydrogen bonds, generating R 1 2(7) ring motifs. These hydrogen bonds link the mol­ecules into infinite chains along the a axis. The crystal structure is further stabilized by weak inter­molecular π–π inter­actions [centroid–centroid distance = 3.4118 (10) Å].

In the title compound, C20H17N7O2S (systematic name: 3-(4-methyl­phen­yl)-4-{3-[(phenyl­amino)­meth­yl]-7H-1,2,4-triazolo[3,4-b][1,3,4]thia­diazin-6-yl}-1,2,3-oxadiazol-3-ium-5-olate), the 3,6-dihydro-2H-1,3,4-thia­diazine ring adopts a half-boat conformation. The oxadiazol-3-ium ring makes dihedral angles of 57.99 (6) and 54.48 (6)° with the phenyl and benzene rings, respectively, while the 1,2,4-triazole ring forms corresponding angles of 37.35 (6) and 73.89 (6)°. The dihedral angle between the oxadiazol-3-ium and 1,2,4-triazole rings is 21.12 (6)°. In the crystal, the mol­ecules are linked via inter­molecular N—H⋯O and C—H⋯N hydrogen bonds into a layer parallel to the (100) plane. The crystal structure is further consolidated by C—H⋯π inter­actions. An intra­molecular C—H⋯O hydrogen bond is also observed, which generates an S(6) ring motif.

In the title compound, C17H11Br3N2O3, the whole mol­ecule is disordered over two positions with a refined occupancy ratio of 0.770 (5):0.230 (5). In the major component, the 1,2,3-oxadiazo­lidine ring is essentially planar [maximum deviation = 0.017 (6) Å] and makes dihedral angles of 22.5 (3) and 70.2 (3)° with the 4-bromo­phenyl and phenyl rings, respectively. In the minor component, the corresponding values are 18.9 (11) and 84.9 (12)°. In the crystal, inter­molecular C—H⋯Br hydrogen bonds link the mol­ecules into ribbons along [010]. There is a short O⋯N contact [2.83 (3) Å] in the minor component. In the major component, the mol­ecular structure is stabilized by an intra­molecular C—H⋯O hydrogen bond, which forms an S(6) ring motif.

In the title compound, C8H6N4O2S, the 1,2,4-triazole ring and the nitro group form dihedral angles of 6.26 (13) and 9.5 (3)°, respectively, with the phenyl ring. In the crystal, the mol­ecules are linked via pairs of N—H⋯S hydrogen bonds, generating [010] chains which contain R 2 2 (8) ring motifs. The crystal structure is further stabilized by π–π stacking [centroid–centroid distance = 3.5491 (14) Å] inter­actions.