9-(Thiophen-2-yl)-8,9-dihydro-3H-pyrazolo[4,3-f]quinolin-7(6H)-one ethanol monosolvate

In the title compound, C14H11N3OS·C2H5OH, the dihedral angle between the pyridine N—Cfused—Cfused—C(thiophene) plane and the plane of the thiophene ring is 81.9 (3)°, indicating that they are close to perpendicular. The dihedral angle between this pyridine plane and the benzene ring is 1.3 (3)°. The thiophene ring is disordered over two coplanar orientations with an occupancy ratio of 0.692 (7):0.308 (7), while the ethanol solvent molecule is also disordered over two sets of site in a 0.66 (4):0.34 (4) ratio. In the crystal, chains are formed along the b axis by N—H⋯O and O—H⋯N interactions with adjacent chains being connected through C—H⋯N and C—H⋯S interactions.

In the title compound, C 14 H 11 N 3 OSÁC 2 H 5 OH, the dihedral angle between the pyridine N-C fused -C fused -C(thiophene) plane and the plane of the thiophene ring is 81.9 (3) , indicating that they are close to perpendicular. The dihedral angle between this pyridine plane and the benzene ring is 1.3 (3) . The thiophene ring is disordered over two coplanar orientations with an occupancy ratio of 0.692 (7):0.308 (7), while the ethanol solvent molecule is also disordered over two sets of site in a 0.66 (4):0.34 (4) ratio. In the crystal, chains are formed along the b axis by N-HÁ Á ÁO and O-HÁ Á ÁN interactions with adjacent chains being connected through C-HÁ Á ÁN and C-HÁ Á ÁS interactions.
Due to their diverse ranges of biological properties, the synthesis of these important molecules has attracted widespread attention. Some researchers have reported the synthesis of quinolinones (Suarez et al., 1999). To the best of our knowledge, however, the pyrazolo[4,3-f]quinolin-7-one derivatives have not been investigated. Because of the biological activities they exhibit, these compounds have distinguished themselves as heterocycles of profound chemical and biological significance.
In the crystal structure of the title compound, the pyridine ring exhibits an envelope-like structure. The dihedral angle between the pyridine C6/C7/C8/N3 plane and the C11/C12/C13/C14/S1 thiophene ring is 81.9 (3)°, indicating that they are close to perpendicular. The dihedral angle between the pyridine C6/C7/C8/N3 plane and the C2-C7 benzene ring is 1.3 (3)°. The thiophene ring is disordered over two coplanar orientations with an occupancy ratio of 0.692 (7):0.308 (7) while the ethanol solvent molecule is also disordered over two sets of positions with a ratio of 0.66 (4)

Refinement
All H atoms were positioned geometrically and treated as riding, with N-H = 0.86 Å and U iso (H) = 1.2U eq (N), with C-H = 0.93 Å and U iso (H) = 1.2U eq (C) for aromatic H atoms, with C-H = 0.97 Å and U iso (H) = 1.2U eq (C) for methylene H atoms, with C-H = 0.96 Å and U iso (H) = 1.5U eq (C) for methyl H atoms, and with O-H = 0.82 Å and U iso (H) = 1.5U eq (O).

Figure 1
The molecular structure of title compound, showing 30% probability displacement ellipsoids.  A packing diagram of title compound viewed along the a axis.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ. (