反应详情

2- Tert-butoxycarbonylmethyl-5-methyl benzoic acid tert-butyl ester (4.751, 15.5 mmol) was dissolved in 75 ml of CCl4. To the solution was added N-bromosuccinimide (2.90 g, 16.3 mmol, 1.05 equivalents) and benzoyl peroxide (180 mg). The reaction mixture was refluxed under an argon atmosphere overnight; the reaction mixture was then cooled to room temperature, and the solid precipitate was filtered off, and washed with hexanes, the combined organic was taken to dryness and the residue was purified by chromatography to obtain 2-tert-butoxycarbonylmethyl-5-bromomethyl benzoic acid tert-butyl ester 2.286 g (38.3% yield) as an oil. 1H NMR (CDCl3): 7.920 (1H, d, J=2.2 Hz), 74.60 (1H, dd, J=1.95, 7.81 Hz), 7.193 (1H, d, J=7.81 Hz), 4.500 (2H, s), 3.953 (2H, s), 1.590 (9H, s), 1.444 (9H, s) FABMS (+Ve), m/z 387 [MH+, 81Br], 385 [MH+, 79Br], 331 [MH+—C4H8, 81Br], 329 [MH+—C4H8, 79Br], 275 [MH+—2C4H8, 81Br], 273 [NH+—2C4H8, 79Br]. Anal. calcd. for C18H25BrO4: C, 56.1; H, 6.5; Br, 20.7. Found: C, 56.27; H, 6.60; Br, 20.75.

1. temperatureThe reaction mixture was refluxed under an argon atmosphere overnight
2. filtrationthe solid precipitate was filtered off
3. washwashed with hexanes
4. customthe residue was purified by chromatography