反应详情

温度

-40 °C

A THF (30 mL) solution containing 1 (0.971 g, 3.5 mmol) and CNBr (1.032 g, 9.8 mmol) was placed in a dry ice and acetone bath at −40° C. Et3N (0.738 g, 7.30 mmol) was added and the solution was allowed to stir at −40° C. for 2 h under N2. The solution was diluted with ether (˜150 mL) and washed with water (2×200 mL), brine (50 mL), and then dried over MgSO4. Removal of the solvent under reduced pressure afforded 2 as an off-white powder (1.06 g, 94%). Further purification can be achieved by recrystallization from acetonitrile (0.96 g, 85%). 1H NMR (CDCl3) δ 6.91 (d, J=2 Hz, 2 H), 6.72 (d, J=2 Hz, 2H), 4.00 (s, 3H) 2.41 (s, 3H); 13C NMR (CDCl3) δ 150.1, 138.9, 137.8, 127.2, 123.1, 114.5, 110.2, 56.7, 21.7. Anal. Calcd for C18H16O4N2: C, 66.86; H, 4.97. Found: C, 65.77; H 5.09.

1. washwashed with water (2×200 mL), brine (50 mL)
2. dry with materialdried over MgSO4
3. customRemoval of the solvent under reduced pressure