Carbon Disulfide → 2-Bromo-5-benzoylthiophene

Participants

Reaction Steps

To a mixture of benzoyl chloride (2.81 g, 20.0 mmol) and 2-bromothiophene (3.42 g, 21.0 mmol) in carbon disulfide (120 mL) aluminum chloride (5.34 g, 40.0 mmol), was added in portions over 10 min with vigorous magnetic stirring. The reaction was next allowed to stir for 2.5 h before being quenched with 100 mL 1 M HCl (aq). The organics were separated, the aqueous layer extracted with carbon disulfide (3×50 mL), and the combined organics washed with water (3×100 mL) and dried over MgSO4. After filtration, the organics were concentrated in vacuo and the residue chromatographed on a silica gel column (hexane:ether=9:1) to yield 5.14 g (96%) of yellow crystals. mp 41-43° C.; 1H NMR (CDCl3): δ 7.84 (d, 2H, 3J=8.0 Hz), 7.62 (t, 1H, 3J=7.2 Hz), 7.52 (t, 2H, 3J=7.5 Hz), 7.40 (d, 2H, 3J=3.5 Hz), 7.15 (d, 2H, 3J=4.0 Hz).

Provenance & Evidence