4-[(5R*,10bR*)-2-Methyl-1,10b-dihydropyrazolo[1,5-c][1,3]benzoxazin-5-yl]benzoic acid

Abstract

In the title compound, C18H16N2O3, a potential inhibitor of the cyclooxygenase-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 opposite sides of the mean plane defined by the other four atoms; the conformation is that of a half-chair. As a result, the molecule as a whole is not planar. The carboxyl group is involved in an intermolecular O—H...N hydrogen bond, which links the molecules into centrosymmetric dimers.