反应详情

2.55 g of 1,2-dibromo-4,5-dimethoxybenzene (8.62 mmol; 2 eq) and 500 mg of 1,1-diethoxyethene (4.31 mmol; 1 eq) in 25 mL of toluene are stirred at 0° C. under argon. 3.5 mL of n-butyllithium (2.5M in hexane, 8.62 mmol; 2 eq) are added dropwise at 0° C. When the addition is complete, the reaction mixture is stirred for 22 hours at ambient temperature. The reaction mixture is then hydrolysed and extracted 3 times with ethyl acetate. The organic phases are dried and evaporated, and the crude product is purified by column chromatography over silica gel (eluant: heptane/ethyl acetate 90/10). There are obtained 333 mg of a yellow oil which crystallises at ambient temperature.

1. additionWhen the addition
2. extractionhydrolysed and extracted 3 times with ethyl acetate
3. customThe organic phases are dried
4. customevaporated
5. customthe crude product is purified by column chromatography over silica gel (eluant: heptane/ethyl acetate 90/10)