In the title compound, C(18)H(16)N(2)O(3), a potential inhibitor of the cyclo-oxygenase-2 isoenzyme, the pyrazoline ring exists in a flattened envelope conformation with one C atom deviating by 0.463 Å from the mean plane of the remaining four atoms. The puckering of the central oxazine ring is more severe, with one N atom and one C atom displaced by 0.235 (6) and 0.370 (2) Å, respectively, on ...

Two independent mol-ecules comprise the crystallographic asymmetric unit in the title anti-retroviral agent Efavirenz, C(14)H(9)ClF(3)NO(2), and these have noteworthy differences in conformation. The major difference relates to the orientation of the 2-cyclo-propyl-ethynyl residue relative to the six-membered heterocycle: this approaches an orthogonal disposition in mol-ecule a compared to a mo...

The organic molecule in the title hydrate, C(9)H(9)N(3)O(3)·H(2)O, was obtained by the condenstation of salicylic aldehyde with urea in acetonitrile. The oxazine ring adopts a slightly distorted sofa conformation, with the N atom deviating from the plane passing through the other atoms of the ring by 0.267 (2) Å. The crystal structure displays inter-molecular N-H⋯O and O-H⋯O hydrogen bonding.

In the crystal structure of the title compound, C(22)H(19)N(3)O(3), inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into a zigzag chain parallel to the face diagonal of the ac plane. The meth-oxy phenyl rings make a dihdral angle of 32.38 (7)° and form dihedral angles of 0.66 (8) and 24.17 (7)° with the fused benzooxazine ring system.

In the title compound, C(11)H(10)N(2)O(2), a potential inhibitor of the cyclo-oxygenase-2 isoenzyme, the pyrazoline ring exists in a flat-envelope conformation while the puckering of the central oxazine ring is more severe. As a result, the mol-ecule as a whole is non-planar. The formal sp(3) pyrazoline N atom is sp(2) hybridized, with the lone-pair electrons delocalized through conjugation wit...

The title compound, C21H18N2O4, crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. In both mol-ecules the oxazine ring has an envelope conformation with the hydroxyl-substituted C atom as the flap. The nitro-benzyl ring and the phenyl ring are almost normal to the mean plane of the benzooxazine ring system with dihdral angles of 85.72 (15) and 82.69 (15)°, respective...