反应详情

To a cooled (0° C.) mixture of 4-[(1S)-1-aminoethyl]benzoic acid (Chem. Eur. J. 1999, 5, 1095, 16.2 g, 98 mmol) and 2 N sodium hydroxide aqueous solution (100 mL) was added benzyl chloroformate (20.5 g, 120 mmol) dropwise over 30 min period followed by the addition of additional 2 N sodium hydroxide aqueous solution (70 mL). The reaction mixture was stirred overnight at room temperature and then acidified to pH 1 with concentrated hydrochloric acid. The resulting precipitate was filtered, washed with water (100 mL), and then vacuum dried to yield 26 g (88%) of the title compounds as white solids: 1H-NMR (CDCl3) δ 7.95 (2H, d, J=8.1 Hz), 7.40–7.15 (7H, m), 5.12–4.94 (3H, m), 4.82 (1H, br.s), 1.40 (3H, d, J=7.0 Hz); MS (ESI) m/z 300 (M+H)+, 298 (M−H)−.

1. temperatureTo a cooled
2. filtrationThe resulting precipitate was filtered
3. washwashed with water (100 mL)
4. customvacuum dried