3-Hydroxy-1,2,3,9-tetrahydropyrrolo[2,1-b]quinazolin-4-ium chloride dihydrate: (+)-vasicinol hydrochloride dihydrate from Peganum harmala L

The title compound, C11H13N2O+·Cl−·2H2O, the dihydrate of (+)-vasicinol hydrochloride, is a pyrrolidinoquinazoline alkaloid. It was isolated from the ethyl acetate fraction of the leaves of Peganum harmala L. The pyrrolidine ring has an envelope conformation with the C atom at position 2 acting as the flap and the C atom at position 3, carrying the hydroxyl substituent, has an S configuration. The absolute configuration was determined as a result of the anomalous scattering of the Cl atom. In the crystal structure, molecules stack along the a axis, connected to one another via intermolecular O—H⋯Cl and N—H⋯Cl hydrogen bonds, forming approximately triangular-shaped R 2 1(7) rings, and O—H⋯Cl and O—H⋯O hydrogen bonds, forming pentagonal-shaped R 5 4(10) rings. The overall effect is a ribbon-like arrangement running parallel to the a axis.

The title compound, C 11 H 13 N 2 O + ÁCl À Á2H 2 O, the dihydrate of (+)-vasicinol hydrochloride, is a pyrrolidinoquinazoline alkaloid. It was isolated from the ethyl acetate fraction of the leaves of Peganum harmala L. The pyrrolidine ring has an envelope conformation with the C atom at position 2 acting as the flap and the C atom at position 3, carrying the hydroxyl substituent, has an S configuration. The absolute configuration was determined as a result of the anomalous scattering of the Cl atom. In the crystal structure, molecules stack along the a axis, connected to one another via intermolecular O-HÁ Á ÁCl and N-HÁ Á ÁCl hydrogen bonds, forming approximately triangular-shaped R 2 1 (7) rings, and O-HÁ Á ÁCl and O-HÁ Á ÁO hydrogen bonds, forming pentagonal-shaped R 5 4 (10) rings. The overall effect is a ribbon-like arrangement running parallel to the a axis.
Data collection: EXPOSE in IPDS-I (Stoe & Cie, 2000); cell refinement: CELL in IPDS-I; data reduction: INTEGRATE in IPDS-I; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97. Peganum harmala L is a member of the family Zygophyllaceae (Hilal and Youngken, 1983). This plant is commonly distributed in the Attock District, Islamabad, including the Margalla Hills. Several alkaloids have been isolated from the seeds and roots of this plant and have been identified as chemicals with a β-carboline structure, such as harmine, harmaline, harmalol, and harman (Bailey, 1986;Rizk, 1986), or with a quinazoline structure, such as vasicine and vasicinon (Openshaw, 1953;Bailey, 1986;Joshi et al., 1996). Here we report on the crystal structure of the title compound, the dihydrate of (+)Vasicinol hydrochloride. It is a pyrrolidino-quinazoline alkaloid and was isolated from the ethylacetate fraction of the leaves of Peganum harmala L, collected from the Margalla Hills, Islamabad.
The absolute configuration of the title compound was determined as a result of the anomalous scattering of the Cl-atom.
In the crystal the molecules stacks up the a axis and are connected to one another via a series of O-H···Cl, N-H···Cl hydrogen bonds, with approximately triangular-shaped R 1 2 (7) rings (Bernstein et al., 1995) and O-H···Cl and O-H···O hydrogen bonds, forming pentagonal-shaped R 5 4 (10) rings [see Fig. 2 and Table 1]. In this way a ribon-like arrangement is formed running parallel to the a axis. The same triangular arrangement, involving O-H···halideand N-H···halidehydrogen bonds, is also observed in the crystal packing of (+)-Vasicine hydrobromide ( Fig. 3; Joshi et al., 1996).

Experimental
Peganum harmala L is a member of the family Zygophyllaceae (Hilal & Youngken, 1983). This plant is commonly distrib-    3. View along the a axis of the crystal packing of (+)-Vasicinol hydrobromide (Joshi et al., 1996), showing the formation of the trianglular-shaped [R 1 2 (7)] rings of hydrogen bonds [Brpurple ball; H-atoms not involved in hydrogen bonding have been removed for clarity].

Special details
Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles 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.