6,7,8,9,10,11-Hexahydro-13H-azocino[2,1-b]quinazolin-13-one

Rasul Ya Okmanov; Zafir U Samarov; Kambarali K Turgunov; Bakhodir Tashkhodjaev; Khusniddin M Shakhidoyatov

doi:10.1107/S160053680902460X

. 2009 Jul 4;65(Pt 8):o1776. doi: 10.1107/S160053680902460X

6,7,8,9,10,11-Hexahydro-13H-azocino[2,1-b]quinazolin-13-one

Rasul Ya Okmanov ^a,^*, Zafir U Samarov ^a, Kambarali K Turgunov ^a, Bakhodir Tashkhodjaev ^a, Khusniddin M Shakhidoyatov ^a

PMCID: PMC2977403 PMID: 21583484

Abstract

The title compound, C₁₄H₁₆N₂O, is a synthetic analogue of quinazolone alkaloids with pyrrilo, pyrido and azopino rings. The quinazolinic part of the molecule is generally planar within 0.037 (3) Å; the eight-membered ring exhibits an intermediate conformation between the chair and boat forms as it is typical for cyclooctene rings. An ethylene group of the azopino ring is disordered over two positions with a refined occupancy ratio of 0.910 (7):0.090 (7). In the crystal, the H atoms of the aromatic rings form weak C—H⋯O and C—H⋯N hydrogen bonds. One C—H⋯O hydrogen bond leads to the formation of a one-dimensional chain. Another C—H⋯O and a C—H⋯N bond link these chains, generating a three-dimensional network.

Related literature

For the synthesis of the title compound, see: Shakhidoyatov et al. (1976 ▶). For its physiological activity, see: Shakhidoyatov (1988 ▶). For crystal structures of pyrido-quinazolone and azopino-quinazolone, see: Tashkhodzhaev et al. (1995 ▶). For spectroscopic data and the chemical structures of pyrido-quinazoline and -quinazolone alkaloids, see: Turgunov et al. (1995 ▶). For cyclooctene ring conformations, see: Barnes et al. (1992 ▶). For weak hydrogen bonds in alkaloids, see: Rajnikant et al. (2005 ▶).

Experimental

Crystal data

C₁₄H₁₆N₂O
M _r = 228.29
Orthorhombic,
a = 9.5490 (19) Å
b = 10.584 (2) Å
c = 11.693 (2) Å
V = 1181.8 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 300 K
0.60 × 0.42 × 0.35 mm

Data collection

Stoe Stadi-4 four-circle diffractometer
Absorption correction: none
1229 measured reflections
1208 independent reflections
1061 reflections with I > 2σ(I)
3 standard reflections frequency: 60 min intensity decay: 3.9%

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.079
S = 1.17
1208 reflections
174 parameters
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.11 e Å⁻³

Data collection: STADI4 (Stoe & Cie, 1997 ▶); cell refinement: STADI4; data reduction: X-RED (Stoe & Cie, 1997 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP (Bruker, 1998 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680902460X/zl2205sup1.cif

e-65-o1776-sup1.cif^{(18.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680902460X/zl2205Isup2.hkl

e-65-o1776-Isup2.hkl^{(59.8KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8A⋯O1ⁱ	0.93	2.64	3.490 (3)	153
C9—H9A⋯N7ⁱⁱ	0.93	2.74	3.660 (3)	170
C10—H10A⋯O1ⁱⁱⁱ	0.93	2.71	3.599 (3)	162

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

We thank the Academy of Sciences of the Republic of Uzbekistan for supporting this study (grant MP-34).

supplementary crystallographic information

Comment

Tricyclic quinazolin-4-ones with polymethylenic fragments and their analogues are widely spread in plants and possess various physiological activities (Shakhidoyatov, 1988). With this in mind the title compound was synthesized (Shakhidoyatov et al., 1976) and its crystal structure has been investigated by single crystal X-ray diffraction.

Figure 1 shows an ortep style plot of the molecular structure of the title compound. An ethylene group of the molecule is disordered over two positions (C3, C3', C4, C4'). Refinement of the structure yielded an occupancy ratio of the disordered atoms (i.e. two conformers) of 0.910 (7):0.090 (7).

The quinazoline part of the molecule is a generally flat within a standard deviation of ±0.037 Å. The electronic system of the N7—C14—N15—C12 fragment of the pyrymidinic ring is delocalized as reflected by the bond lengths. The length of the formal double bond N7═C14 and the single bond C14—N15 in the structure of the title compound are 1.297 (3) and 1.383 (3) Å, respectively, which is in agreement with the range observed in crystals of pyrrilo, pyrido, and azopino quinazolones (Turgunov et al., 1995; Tashkhodzhaev et al., 1995). The length of the C═O bond (1.227 (3) Å) is also compareable to those observed in above mentioned analogues. The eight-membered ring has taken on an intermediate form between a chair and boat conformation typical for cycloectene rings (Barnes et al., 1992).

In the crystal structure of the title compound weak intermolecular C-H···X hydrogen bonds are observed as it is often the case in alkaloids (Rajnikant et al., 2005). The hydrogen bond C8–H8A···O1ⁱ leads to the formation of a one dimensional chain. Another C–H···O and a C–H···N bond (C10–H10A···O1ⁱⁱⁱ and a C9–H9A···N7ⁱⁱ) link these chains to generate a three-dimensional network (Fig. 2 and 3; for numerical values and symmetry operators see Table 1).

Experimental

The title compound was synthesized on the basis of a well–known method (Shakhidoyatov, et al., 1976). Powder of title compound was dissolved in hot aqueous ethanol and from the solution yellow prismatic crystals were obtained during slow evaporation in a thermostat at a temperature of 313 K.