反应详情

温度

140 °C

90.0 g of 3,4-dimethoxy-ω-nitrostyrene (compound G2), 90 ml of 2-trimethylsilyloxy-1,3-butadiene and 180 ml of abs. Toluene are put in an autoclave, where the mixture is stirred at 140° C. for 2 days and then cooled. After addition of 1000 ml of ethyl acetate, 300 ml of a 2 N solution of hydrochloric acid are dropped under stirring. The phases are separated and the aqueous layer is extracted three times with dichloromethane. The combined organic extracts are washed with saturated sodium hydrogencarbonate solution, dried over magnesium sulfate and the solvents are removed under reduced pressure to give 150 g of the crude title compound. Further purification is carried out by chromatography on silica gel using petroleum ether/ethyl acetate in the ratio 1/1 as eluent to give 81.5 g (67% of theory) of the pure title compound.

1. temperaturecooled
2. additionare dropped
3. stirringunder stirring
4. customThe phases are separated
5. extractionthe aqueous layer is extracted three times with dichloromethane
6. washThe combined organic extracts are washed with saturated sodium hydrogencarbonate solution
7. dry with materialdried over magnesium sulfate
8. customthe solvents are removed under reduced pressure
9. customto give 150 g of the crude title compound
10. customFurther purification