Synthesis and crystal structure of 2- (2, 4-dioxo-6-methylpyran-3-ylidene) -4- (4-hydroxyphenyl) -2, 3, 4, 5-tetrahydro-1H-1, 5-benzodiazepine

The title compound, C₂₁H₁₈N₂O₄, contains non-planar diazepine (in a boat–sofa conformation) and pyran (envelope) rings. In the crystal, O—H. . . O and N—H. . . O hydrogen bonds link the molecules, enclosing R ₂ ^2 (16) and R ₂ ^2 (24) ring motifs, to generate 110 chains. Very weak π–π stacking interactions between the phenyl rings of adjacent molecules with an inter-centroid distance of 4. 0264 (9) Å help to consolidate a three-dimensional architecture. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H. . . H (45. 1%), H. . . O/O. . . H (23. 2%) and H. . . C/C. . . H (19. 2%) interactions.