3-Benzyl-1-butyl­imidazo[1,2-a]benzo­thieno[3,2-d]pyrimidine-2,5(1H,3H)-dione

Min-Hui Cao; Jun Zhu; De-Jiang Ni

doi:10.1107/S1600536807061521

. 2007 Dec 6;64(Pt 1):o10. doi: 10.1107/S1600536807061521

3-Benzyl-1-butylimidazo[1,2-a]benzothieno[3,2-d]pyrimidine-2,5(1H,3H)-dione

Min-Hui Cao ^a, Jun Zhu ^b, De-Jiang Ni ^c,^*

PMCID: PMC2914972 PMID: 21200666

Abstract

In the crystal structure of the title compound, C₂₃H₂₁N₃O₂S, all ring atoms of the imidazo[1,2-a]benzothieno[3,2-d]pyrimidine system are essentially coplanar and the phenyl ring is twisted with respect to it [dihedral angle = 72.60 (9)°]. The crystal packing is mainly governed by C—H⋯π hydrogen bonds and intermolecular π–π interactions, with interplanar distances of 3.54 (1) and 3.56 (1) Å, and with distances between adjacent ring centroids of 3.72 (1) and 3.80 (1) Å. The three terminal C atoms of the butyl group are disordered over two positions; the site occupancy factors are ca 0.6 and 0.4.

Related literature

Related preparation and biological activity is described by Walter (1999a ▶,b ▶). For related literature, see: Ding et al. (2004 ▶); Janiak (2000 ▶). For the crystal structures of other fused pyrimidinone derivatives, see: Cao et al. (2006 ▶); Xu et al. (2005 ▶).

Experimental

Crystal data

C₂₃H₂₁N₃O₂S
M _r = 403.49
Monoclinic,
a = 13.1732 (16) Å
b = 8.4957 (11) Å
c = 18.584 (2) Å
β = 103.345 (2)°
V = 2023.7 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.18 mm⁻¹
T = 298 (2) K
0.26 × 0.16 × 0.10 mm

Data collection

Bruker SMART 4K CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ▶) T _min = 0.954, T _max = 0.982
15534 measured reflections
3958 independent reflections
2896 reflections with I > 2σ(I)
R _int = 0.129

Refinement

R[F ² > 2σ(F ²)] = 0.059
wR(F ²) = 0.170
S = 1.00
3958 reflections
292 parameters
22 restraints
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT-Plus (Bruker, 2001 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: PLATON (Spek, 2003 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2001 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807061521/at2501sup1.cif

e-64-00o10-sup1.cif^{(24.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807061521/at2501Isup2.hkl

e-64-00o10-Isup2.hkl^{(194KB, hkl)}

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

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

Cg5 is the centroid of the C18–C23 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4⋯Cg5ⁱ	0.96	2.81	3.682 (3)	156

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Symmetry code: (i) Inline graphic .

Acknowledgments

We gratefully acknowledge financial support of this work by the National Natural Science Foundation of China (project No. 20102001).

supplementary crystallographic information

Comment

In the field of bioactive molecules, thienopyrimidine have received a great deal of attention (Walter, 1999a,b). Recently, There have being focused on the synthesis of the fused heterocycle systems containing thienopyrimidine via aza-Wittig reaction at room temperature(Ding et al., 2004). Herein, we present X-ray crystallographic analysis of the compound (I) in this paper, (Fig. 1), which may be used as a new precursor for obtaining bioactive molecules.

In the molecule, the bond lengths and angles are unexceptional (Cao et al., 2006; Xu et al., 2005). The four fused rings are close to coplanarity, with maximum deviations 0.060 (2)Å and -0.033 (3)Å for O3 and C11, respectively, which forms a dihedral angle of 72.60 (9)° with the adjacent C18—C23 phenyl ring.

Intermolecular C—H···π hydrogen bonds (Table 2) seem to be effective in stabilizing the crystal structure. Further stability the crystal structure is provided by offset π-π stacking interactions (Janiak, 2000) involving the thiophene (A), the imidazoe (B) and the C1—C6 benzene (C) rings. The A:C interplanar distance is 3.54 (1) Å with distances between adjacent ring centroids of 3.72 (1)Å (symmetry code relating the adjacent rings: 1 - x, 2 - y, -z). A further interaction occurs between B adjacent C rings (symmetry code: 1 - x, 1 - y, -z), with an interplanar distance of 3.56 (1)Å and a centroid-to-centroid distance of 3.80 (1)Å (Fig. 2).

Experimental

To a solution of the ethyl 3-((butylimino)methyleneamino)benzothiophene-2-carboxylate (3 mmol) in dichloromethane (5 ml) was added ethyl 2-amino-3-phenylpropanoate (3 mmol). After stirring the reaction mixture for 2 h, the solvent was removed and anhydrous ethanol (10 ml) with several drops of EtONa in EtOH was added. The mixture was stirred for 5 h at room temperature. The solution was concentrated under reduced pressure and the residue was recrystallized from ethanol to give the title compound in a yield of 86%. Crystals suitable for single-crystal X-ray diffraction were obtained by recrystallization from a mixed solvent of ethanol and dichloromethane (1:3 v/v) at room temperature.