反应详情

N-bromosuccinimide (18.5 g, 0.103 mol) was added to a solution of methyl 5-tert-butyl-3-methylthiophene-2-carboxylate (109b) (20 g, 0.09 mol) and AIBN (0.774 g, 0.0047 mol) in CCl4 (200 mL). The mixture was refluxed for 2 h, cooled to room temperature and filtered. The filtrate was concentrated under vacuum and the obtained residue was purified by flash column chromatography (silica, 95:5 hexanes-/dichloromethane) to afford methyl 3-(bromomethyl)-5-tert-butylthiophene-2-carboxylate (109c) (11 g, 40%) as a pale yellow liquid.

1. temperatureThe mixture was refluxed for 2 h
2. filtrationfiltered
3. concentrationThe filtrate was concentrated under vacuum
4. customthe obtained residue was purified by flash column chromatography (silica, 95:5 hexanes-/dichloromethane)