(E)-3-Propoxymethylidene-2,3-dihydro-1H-pyrrolo[2,1-b]quinazolin-9-one monohydrate

The title compound, C15H16N2O2·H2O, was synthesized via the alkylation of 3-hydroxymethylidene-2,3-dihydro-1H-pyrrolo[2,1-b]quinazolin-9-one with n-propyl iodide in the presence of sodium hydroxide. The organic molecule and the water molecule both lie on a crystallographic mirror plane. In the crystal structure, intermolecular O—H⋯O and O—H⋯N hydrogen bonds link the components into extended chains along [100].

The title compound, C 15 H 16 N 2 O 2 ÁH 2 O, was synthesized via the alkylation of 3-hydroxymethylidene-2,3-dihydro-1H-pyrrolo-[2,1-b]quinazolin-9-one with n-propyl iodide in the presence of sodium hydroxide. The organic molecule and the water molecule both lie on a crystallographic mirror plane. In the crystal structure, intermolecular O-HÁ Á ÁO and O-HÁ Á ÁN hydrogen bonds link the components into extended chains along [100].
Using the typical synthesis for O-alkyl derivatives the reaction of 3-hydroxymethylidene-2,3-dihydro-1H-pyrrolo[2,1b]quinazolin-9-one with n-propyl iodide was carried out by boiling of the initial reagents (1:2 ratio) over 7 hours in ethanol in the presence of sodium hydroxide (Elmuradov et al., 2006) (Allen et al., 1987) and angles in molecule are in normal ranges.
The mixture was heated to reflux on a water bath for 7 hours. The solvent was distilled off and the residue was re-crystallized from hexane. The title compound was obtained in 70 % yield (0.18 g). Colorless crystals suitable for X-ray analysis were obtained from hexane by slow evaporation.

Refinement
Carbon-bound H atoms were positioned geometrically and treated as riding on their C atoms, with C-H distances of 0.93 Å (aromatic) and 0.97 Å (CH 2 ) and 0.96 Å (CH 3 ) and were refined with U iso (H) =1.2U eq (C)]. The H atoms of the water molecule involved in the intramolecular hydrogen bonds were located by difference Fourier synthesis and refined freely  Fig. 1. The reaction scheme. Fig. 2. The molecular structure of (I), with atom labels and 50% probability displacement ellipsoids for non-H atoms.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 Rfactors(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 )