反应详情

To an ice-cold solution of tert-butyl (5-hydroxypentan-2-yl)carbamate (3.6 g, 17.71 mmol) in dichloromethane (150 mL) was added triphenylphosphine (6.97 g, 26.6 mmol) followed by carbon tetrabromide (8.81 g, 26.6 mmol). The reaction mixture was stirred at room temperature for 18 h while monitoring by TLC. The solvent was removed under reduced pressure and the residue was purified by column chromatography (60-120 mesh silica) using 2-5% ethyl acetate in pet-ether to give tert-butyl (5-bromopentan-2-yl)carbamate (2.5 g, 53%) as a light brown liquid. 1H NMR: (400 MHz, CDCl3) δ ppm 4.29 (1H, br s), 3.68 (1H, br s), 3.42 (2H, t, J=6.8 Hz), 1.94-1.86 (2H, m), 1.59-1.46 (2H, m), 1.44 (9H, s), 1.13 (3H, d, J=6.4 Hz).

1. customThe solvent was removed under reduced pressure
2. customthe residue was purified by column chromatography (60-120 mesh silica)