1-(3-Bromo-2-thienyl)ethanone

In the title compound, C6H5BrOS, the non-H and aromatic H atoms lie on a crystallographic mirror plane. In the crystal, molecules are linked into chains propagating along the c axis by intermolecular C—H⋯O hydrogen bonds.

In the title compound, C 6 H 5 BrOS, the non-H and aromatic H atoms lie on a crystallographic mirror plane. In the crystal, molecules are linked into chains propagating along the c axis by intermolecular C-HÁ Á ÁO hydrogen bonds.   Table 1 Hydrogen-bond geometry (Å , ).
SNS is grateful to University Grants Commission (UGC), Government of India, for financial support under the major research project [grant No. 38-220/2009 (SR)]. SNS also expresses his sincere gratitude to J. S. S. Mahavidyapeetha for the encouragement towards this research work. MM thanks the University of Mysore for awarding a project (No. DV3/ 136/2007-2008. Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CI5166).  (Lutz et al. 2005;Pelly et al. 2005). It is used as an intermediate for the synthesis of furo[3,2-a]carbazole alkaloid, furostifoline (Ito et al. 1990) and its derivatives, which show broad pharmacological properties (Yasuhara et al. 2002). Chalcones of 2-acetyl-3-bromothiophene exhibit promising anti-inflammatory, analgesic and antibacterial activities (Ashalatha et al. 2009). Acetyl thiophenes are useful as intermediates for preparing number of pharmaceutical compounds (Bando et al. 2010). Acetyl bromothiophenes are also used for the synthesis of number of biologically active pyridazine derivatives (Nakayama et al. 1989). With this background, the title compound (I), was synthesized and we report its crystal structure here.

Structure Reports Online
The non-hydrogen and aromatic hydrogen atoms of the title molecule lie on a crystallographic mirror plane (Fig. 1). The molecules are linked into a chain along the c axis by intermolecular C-H···O hydrogen bonds (Table 1).

Experimental
A three-necked, round-bottomed flask was charged with CH 2 Cl 2 (10 ml) and anhydrous AlCl 3 (2.45 g, 18.4 mmol). The flask was cooled to 273 K. A dropping funnel was charged with freshly distilled acetyl chloride (1.48 g, 19.6 mmol) in CH 2 Cl 2 (15 ml), and was added drop wise for a period of 30 min. The reaction mixture was stirred for 1 h at 273 K. The reaction mass was further cooled to 250 K. 3-Bromothiophene (1.00 g, 6.13 mmol) in CH 2 Cl 2 (15 mL) was added drop wise for 1 h. The reaction was stirred at 250 K for 30 min and then warmed slowly to room temperature and stirred for 1 h. Then the reaction mixture was quenched on ice water (50 ml). Layers were separated and aqueous layer was repeatedly extracted with CH 2 Cl 2 and the combined organic extracts were washed with saturated NaHCO 3 (25 ml), then brine (25 ml) and finally dried over anhydrous Na 2 SO 4 . Solvent was removed by distillation at atmospheric pressure. The remaining oily mass was distilled under high vacuum (403 K at 10 mbar) to give a pale yellow oil which was crystallized in n-hexane to give 2-acetyl-3-bromothiophene (1.10 g, 88 %) as a yellow solid. Block-shaped yellow single crystals were obtained by slow evaporation of an n-hexane solution.
Refinement H atoms were placed at idealized positions and allowed to ride on their parent atoms with C-H distances in the range 0.93-0.96 Å and U iso (H) = 1.2-1.5U eq (carrier atom).