反应详情

温度

90 °C

A mixture of 3,4-dichlorocinnamic acid (50 g, 0.23 mole), benzene (150 mL) and concentrated sulfuric acid (100 mL) was stirred (using air driven overhead stirrer) in a 500 mL 3-neck round bottom flask while maintaining a reaction temperature of 85-95° C. The progress of the reaction was followed by HPLC. When the level of 3,4-dichlorocinnamic acid was <1% by HPLC (approximately 24 h), the reaction mixture was cooled to room temperature, then slowly poured into ice (300 g). The mixture was stirred for 30 min. then transferred into a 2 L separatory funnel. The organic layer was separated from the aqueous layer, and the aqueous layer was extracted with ethyl acetate (2×300 mL). The organic layers were combined, washed with water (5×500 mL) and brine (2×400 mL), then concentrated under reduced pressure. Ethyl acetate (500 mL) was added to the concentrate and the solution was evaporated to dryness. The product was dried under high vacuum at room temperature for 24 h. The desired carboxylic acid was obtained as a thick oil (65.8 g, 96% yield).

1. customby HPLC (approximately 24 h)
2. temperaturethe reaction mixture was cooled to room temperature
3. stirringThe mixture was stirred for 30 min.
4. customthen transferred into a 2 L separatory funnel
5. customThe organic layer was separated from the aqueous layer
6. extractionthe aqueous layer was extracted with ethyl acetate (2×300 mL)
7. washwashed with water (5×500 mL) and brine (2×400 mL)
8. concentrationconcentrated under reduced pressure
9. additionEthyl acetate (500 mL) was added to the
10. concentrationconcentrate
11. customthe solution was evaporated to dryness
12. customThe product was dried under high vacuum at room temperature for 24 h