反应详情

温度

-78 °C

tert-Butyllithium (1.7M solution in pentane, 15 mmol) is added to a solution of 2-bromo-3,4,5-trimethoxybenzoic acid 5 (5 mmol, synthesis described in Example 12) in 50 mL of THF, while maintaining the temperature of the mixture below −95° C. After the addition is completed, the mixture is allowed to warm to −78° C. After 30 minutes, benzyl chloroformate (5 mmol) is added in one portion, and the mixture is allowed to warm to 0° C. Water (50 mL) is added, and then the pH of the mixture is carefully adjusted to 3 using 0.1 M HCl. The mixture is extracted with ethyl acetate (5×100 mL). The organic phases are dried over anhydrous Na2SO4 and concentrated in vacuo. The mixture is purified by flash chromatography to give the product as a colorless oil.

1. temperaturewhile maintaining the temperature of the mixture below −95° C
2. additionAfter the addition
3. temperatureto warm to 0° C
4. extractionThe mixture is extracted with ethyl acetate (5×100 mL)
5. dry with materialThe organic phases are dried over anhydrous Na2SO4
6. concentrationconcentrated in vacuo
7. customThe mixture is purified by flash chromatography