6-Amino-3,4-dimethyl-4-phenyl-2H,4H-pyrano[2,3-c]pyrazole-5-carbonitrile

In the title compound, C15H14N4O, the pyrazole ring is aligned at 88.23 (4)° with respect to the aromatic ring and at 3.75 (4)° with respect to the pyran ring. In the crystal, N—H⋯N hydrogen bonds link adjacent molecules into a linear chain motif. C—H⋯N interactions are also observed.

In the title compound, C 15 H 14 N 4 O, the pyrazole ring is aligned at 88.23 (4) with respect to the aromatic ring and at 3.75 (4) with respect to the pyran ring. In the crystal, N-HÁ Á ÁN hydrogen bonds link adjacent molecules into a linear chain motif. C-HÁ Á ÁN interactions are also observed.

Comment
The pyrano pyrazole derivatives are widely used as organic intermediates (Liang et al., 2009) and are well known for their biological contribution as ChK1 inhibitors. In view of the growing importance of the pyrano pyrazole derivatives, we have synthesized the title compound by Rapid four-component reactions in water (Vasuki & Kumaravel, 2008) and the single-crystal structure analysis was undertaken.
In the title compound, the attached benzyl ring makes the dihedral angle of 88.23 (4) ° and orient in (+)-syn-clinal conforamtion with pyrazole ring, whereas the fused pyrazole ring makes 3.75 (4) ° dihedral angle and orient by an (+)-synperiplanar conformation with respect to the pyran ring ( Fig. 1). The methyl group is attached to C6 atom of pyran with an angle of 109.29 (11) °. Two N-H···N and C-H···N intermolecular hydrogen bond interactions ( Fig. 2) are observed for maintaining the crystal packing ( Fig. 3), in which the N3-H···N4 intermolecular interaction are observed to form R 2 2 (12) ring motifs (Fig. 4). The weak N-H···π intermolecular interaction is also observed for the stabilization of the crystal packing, with a bond distance of 3.382 (3) Å (Fig. 5).

Experimental
The title compound was prepared by the successive addition of acetophenone 2 (0.240 g, 2 mmol), malononitrile (0.132 g, 2 mmol) and piperidine (5 mol%) to a stirred aqueous mixture of hydrazine hydrate 96% 1 (0.107 g, 2 mmol) and ethyl acetoacetate 2 (0.520 g, 2 mmol) at room temperature under an open atmosphere with vigorous stirring for 5-10 min. The precipitated solid was then filtered, followed by washing with water and then with a mixture of ethyl acetate/hexane (20:80).

Refinement
All hydrogen atoms were placed in calculated positions, with N-H=0.86 and C-H=0.93-0.97 and included in the final cycles of refinement using a riding model with U(H) = 1.2 U eq (C).
supplementary materials sup-2 Figures Fig. 1. The molecular structure of (I), showing the atom-numbering scheme and displacement ellipsoids drawn at the 50% probability level.    Cg is a centroid of C 8 -C 13 ring.