反应详情

温度

50 °C

To a solution of 1-Fluoro-2-isocyanato-4-nitro-benzene (9.82 g, 54 mmol) in THF (40 ml) at 23° C. under an atmosphere of argon was added 2-Trimethylsilanyl-ethanol (7.72 ml, 54 mmol). The resulting mixture was stirred for 11 hours then heated to 50° C. for 2 hours. The reaction mixture was allowed to cool to 23° C. quenched with saturated NaHCO3 (aq) and extracted with EtOAc (3×100 ml). The pooled ethyl acetate was washed with 1N HCl (aq) (2×90 ml) water (90 ml) and brine (90 ml), dried with Na2SO4, filtered and concentrated to a yellow solid. Silica gel chromatography (2:8 ethyl acetate-hexane) provided (2-Fluoro-5-nitro-phenyl)-carbamic acid 2-trimethylsilanyl-ethyl ester (12.3 g, 77%). 1H NMR (300 MHz, CDCl3) δ 9.06 (dd, 1H, J=6.89 Hz, J=2.63 Hz), 7.89 (m, 1H), 7.20 (m, 1H), 6.91 (bs, 1H), 4.31 (t, 2H, J=8.67 Hz), 1.06 (t, 2H, J=8.67 Hz), 0.05 (s, 9H). LCMS (ESI−) [M+H]/z Calc'd 299. found 299.

1. temperatureto cool to 23° C.
2. customquenched with saturated NaHCO3 (aq)
3. extractionextracted with EtOAc (3×100 ml)
4. washThe pooled ethyl acetate was washed with 1N HCl (aq) (2×90 ml) water (90 ml) and brine (90 ml)
5. dry with materialdried with Na2SO4
6. filtrationfiltered
7. concentrationconcentrated to a yellow solid