反应详情

温度

-78 °C

A solution of 4-bromo-2-ethyl-1-methoxybenzene (J. Chem. Soc., Perkin Trans. 1, 1987, 1423; 2.13 g, 9.9 mmol) in THF (30 ml) was cooled to −78° C. A 1.6M solution of n-BuLi in hexane (7.42 ml, 11.9 mmol) was added slowly and the mixture was stirred for 1.5 h. at −78° C. The mixture was warmed slowly to −10° C. and subsequently again cooled to −78° C. DMF (2.29 ml, 29.7 mmol) was added slowly and the mixture was stirred for 1 h. at −78° C. and for 1 h. at 0° C. The reaction mixture was poured into ice-cold 3M HCl and extracted with diethyl ether. The organic phase was dried and filtered, and the filtrate was concentrated. The residue was purified by chromatography (SiO2, hexane/EtOAc 8:1=>2:1). There were obtained 690 mg (42%) of 3-ethyl-4-methoxy-benzaldehyde as a yellowish liquid.

1. temperatureThe mixture was warmed slowly to −10° C.
2. temperaturesubsequently again cooled to −78° C
3. stirringthe mixture was stirred for 1 h. at −78° C. and for 1 h. at 0° C
4. extractionextracted with diethyl ether
5. customThe organic phase was dried
6. filtrationfiltered
7. concentrationthe filtrate was concentrated
8. customThe residue was purified by chromatography (SiO2, hexane/EtOAc 8:1=>2:1)