Carbon tetrabromide → 2-(Bromomethyl)-3-chloro-1-benzothiophene

Participants

Reaction Steps

A solution of triphenylphosphine (1.74 g, 6.62 mmol) in dry CH2Cl2 (6 mL) was added dropwise to a stirred solution of carbon tetrabromide (2.20 g, 6.62 mmol) and (3-chloro-1-benzothien-2-yl)methanol (0.94 g, 4.73 mmol) in dry CH2Cl2 (35 mL) at 0° C. under N2. The reaction was allowed to warm to room temperature and was stirred for 4 h then concentrated in vacuo to give the crude product. This was purified by flash chromatography (Si, 40×160 nm, 0-25% EtOAc in hexanes gradient) to afford 2-(bromomethyl)-3-chloro-1-benzothiophene. Rf=0.93 (20% EtOAc/hexanes). 1H NMR (600 MHz, CDCl3): δ 7.81 (dd, J=1.3, 7-1 Hz, 1H); 7.78 (dd, J=1.2, 7.2 Hz, 1H); 7.47-7.41 (m, 2H); 4.81 (s, 2H).

Provenance & Evidence