Synthesis and crystal structure of 2-amino-4-(3-isobutyl-1-phenyl-1H-pyrazol-4-yl)-7,7-dimethyl-5-oxo-5,6,7,8-tetra-hydro-4H-chromene-3-carbo-nitrile.

The title com-pound, C25H28N4O2, crystallizes in space group P1 with Z = 4. The two independent mol-ecules are related by the approximate translation (x + 1, y + 1, z), but differ in the orientation of the phenyl substituent. Crystals are non-merohedrally twinned by a 180° rotation about c*. In the modified chromene ring systems, the two formal double bonds are the shortest C-C bonds. The oxo ring displays a flattened boat conformation, whereas the other ring is approximately a flattened envelope, with the CMe2 C atom out of the plane. The mol-ecules are connected by classical N-H⋯Npyrazole hy-dro-gen bonds to form a ribbon of alternating independent mol-ecules parallel to [110]. The ribbons are joined by weak Cpyrazole-H⋯Nnitrile hy-dro-gen bonds to form a layer structure parallel to the ab plane in the region z ≃ 3/4.