反应详情

A solution of 4-(2-methoxyethoxy)aniline (0.397 g, 2.37 mmol) and pyridine (1 mL, 12.4 mmol) in DCM (3 mL) in was treated with 4-nitrophenyl chloroformate (Aldrich) (0.505 g, 2.51 mmol) added in portions (exothermic!). The pale yellow solution was stirred at RT for 5 h. The reaction mixture was partitioned between 0.5N HCl (20 mL) and DCM (30 mL). The organic phase was washed with 0.5N HCl (30 mL), saturated aqueous sodium bicarbonate (30 mL), water (30 mL) and saturated aqueous sodium chloride (30 mL). The organic phase was dried over sodium sulfate, filtered and concentrated in vacuo. The crude product was purified by silica gel chromatography (50 g, eluent: EtOAc in hexanes 10%-50%) to give 4-nitrophenyl 4-(2-methoxyethoxy)phenylcarbamate (0.57 g, 72% yield) as an off—white solid. 1H NMR (400 MHz, CDCl3) δ 8.25-8.32 (m, 2H); 7.32-7.43 (m, 4H); 6.87-6.97 (m, 3H); 4.09-4.15 (m, 2H); 3.72-3.79 (m, 2H); 3.46 (s, 3H). m/z (ESI, +ve ion) 333.0 (M+H)+.

1. additionadded in portions (exothermic!)
2. customThe reaction mixture was partitioned between 0.5N HCl (20 mL) and DCM (30 mL)
3. washThe organic phase was washed with 0.5N HCl (30 mL), saturated aqueous sodium bicarbonate (30 mL), water (30 mL) and saturated aqueous sodium chloride (30 mL)
4. dry with materialThe organic phase was dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe crude product was purified by silica gel chromatography (50 g, eluent: EtOAc in hexanes 10%-50%)