反应详情

2.10 g of 2-ethyl-4-hydroxy-3-methylbenzoic acid (E1) are dissolved in 50 ml of acetone. 3.30 ml of benzyl bromide and 5.10 g of K2CO3 are subsequently added. The reaction suspension is heated under reflux for 18 h overnight, subsequently filtered off with suction, and the filtrate obtained is evaporated to dryness in vacuo. The residue is dissolved in 40 ml of ethanol, and 40 ml of 2.0 N NaOH solution are added. The mixture is then heated under reflux for 3 h. The clear solution is diluted with 150 ml of water and adjusted to pH 1 using 20% hydrochloric acid. After stirring for 30 min, the precipitate formed is filtered off with suction, rinsed with water and dried at 90° C. in vacuo overnight, giving 2.45 g of the title compound as a beige, amorphous solid having a melting point of 169° C.; MS: 270.0 (M+); TLC: Rf=0.36 (cyclohexane/ethyl acetate 2:1 parts by volume).

1. temperatureThe reaction suspension is heated
2. temperatureunder reflux for 18 h overnight
3. filtrationsubsequently filtered off with suction
4. customthe filtrate obtained
5. customis evaporated to dryness in vacuo
6. dissolutionThe residue is dissolved in 40 ml of ethanol
7. addition40 ml of 2.0 N NaOH solution are added
8. temperatureThe mixture is then heated
9. temperatureunder reflux for 3 h
10. additionThe clear solution is diluted with 150 ml of water
11. customthe precipitate formed
12. filtrationis filtered off with suction
13. washrinsed with water
14. customdried at 90° C. in vacuo overnight