反应详情

温度

0 °C

Under an N2 atmosphere, 2,3-dimethylanisaldehyde (3.0 g, 18.3 mmol) was dissolved in dichloromethane (100 mL) and cooled to 0° C. Carbon tetrabromide (9.10 g, 27.4 mmol) was added followed by a dropwise addition of triphenylphosphine (14.4 g, 54.9 mmol) in dichloromethane (100 mL). The reaction was allowed to stir at 1.5 h at 0° C. The reaction was concentrated in vacuo, and the resulting residue was suspended in a mixture of hexanes and chloroform (4:1). The solid was removed by filtration and discarded. The filtrate was concentrated in vacuo and flash column chromatographed on silica gel eluting with 0% to 40% ethyl acetate in hexanes to yield the desired product. 1H NMR (400 MHz) (CDCl3) δ 7.44 (s, 1H); 7.19 (d, J=8.0 Hz, 1H): 6.72 (d, J=8.0 Hz, 1H), 3.82 (s, 3H); 2.17 (s, 3H); 2.16 (s, 3H).

1. concentrationThe reaction was concentrated in vacuo
2. additionthe resulting residue was suspended in a mixture of hexanes and chloroform (4:1)
3. customThe solid was removed by filtration
4. concentrationThe filtrate was concentrated in vacuo and flash column
5. customchromatographed on silica gel eluting with 0% to 40% ethyl acetate in hexanes