反应详情

A mixture of 5-fluoro-2-methyl-1,3-benzothiazole (500 mg, 2.99 mmol), NBS (600 mg, 3.37 mmol) and AIBN (125 mg, 0.76 mmol) in carbon tetrachloride (25 ml) was heated at reflux for 20 hours under nitrogen with stirring. The solution was then concentrated to give a residue which was purified by silica gel column chromatography using 1% ethyl acetate in petroleum ether to afford 2-(bromomethyl)-5-fluoro-1,3-benzothiazole as a yellow solid (150 mg, 20%). 1H NMR (400 MHz, CDCl3): δ 7.81 (dd, J=8.8, 5.2 Hz, 1H), 7.70 (dd, J=9.2, 2.4 Hz, 1H), 7.23-7.16 (m, 1H), 4.80 (s, 2H).

1. temperaturewas heated
2. temperatureat reflux for 20 hours under nitrogen
3. concentrationThe solution was then concentrated
4. customto give a residue which
5. customwas purified by silica gel column chromatography