[Br:1][C:2]1[CH:3]=[CH:4][C:5]([CH3:13])=[C:6]([CH:12]=1)[C:7]([O:9][CH2:10][CH3:11])=[O:8].[Br:14]N1C(=O)CCC1=O.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>C(Cl)(Cl)(Cl)Cl>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([CH2:13][Br:14])=[C:6]([CH:12]=1)[C:7]([O:9][CH2:10][CH3:11])=[O:8]A mixture of ethyl 5-bromo-2-methylbenzoate (7.52 g, 30.9 mmol), N-bromosuccinimide (6.05 g, 34.0 mmol) and benzoyl peroxide (0.75 g, 3.10 mmol) in carbon tetrachloride (150 ml) was heated to 70° C. in an oil bath for 18 h. After this time, the mixture was cooled to room temperature and the solids removed by filtration. The filtrate was then concentrated under reduced pressure and purified by flash chromatography (silica, gradient 1-10%, ethyl acetate/hexanes) afforded ethyl 5-bromo-2-(bromomethyl)benzoate (7.57 g, 76%) as a clear oil: 1H NMR (300 MHz, CDCl3) 8.09 (d, J=2.2 Hz, 1H), 7.61 (dd, J=8.3, 2.2 Hz, 1H), 7.33 (d, J=8.2 Hz, 1H), 4.90 (s, 2H), 4.42 (q, J=7.2 Hz, 2H), 1.43 (t, J=7.1 Hz, 3H).
読み込み中…
