Methyl 5′-(2-hydroxyphenyl)-4′,5′,6′,7′-tetrahydrospiro[2H-1-benzopyran-2,7′-1,2,4-triazolo[1,5-a]pyrimidine]-3-carboxylate

There are two crystallographically independent molecules in the asymmetric unit of the title compound, C21H18N4O4. The substituted benzopyran portion of one of the independent molecules exhibits disorder [occupancy 0.5248 (18): 0.4752 (18)], which was modelled by using two sets of atomic positions and restraints on the chemically equivalent bond lengths and angles. The central, partially saturated pyrimidine rings of both independent molecules were found to assume unsymmetrical half-chair conformations. The hydroxyphenyl substituent occupies an equatorial position in both molecules, and is rotated by 55.6 (1)degrees from the mean plane of the pyrimidine ring in one independent molecule, and by 53.4 (1)degrees in the other. In the crystal, there are two types of intermolecular hydrogen bond present: reciprocal N-H center dot center dot center dot N interactions join the two crystallographically independent molecules into a dimer and O-H center dot center dot center dot N interactions link the dimers into sheets in the ab plane.