反应详情

2-Bromobutyryl bromide (31.1 ml) was added to a stirred solution of 2,6-dimethoxy-4-methylphenol (45 g) in dry dichloromethane (500 ml), whereupon triethylamine (37.3 ml) was added dropwise over 30 minutes, maintaining the internal temperature below 10° C. using an ice-salt bath. During the addition a white precipitate formed. After addition was complete the reaction mixture was stirred for 1.5 hours, then filtered. The solid was washed with diethyl ether (200 ml) and the filtrate washed twice with saturated sodium bicarbonate solution (100 ml). The organic phase was dried over magnesium sulphate, filtered and the solvent removed under reduced pressure to give the crude product as an oil (79.4 g). To remove any residual starting phenol, the oil was dissolved in diethyl ether and washed with sodium hydroxide solution (0.1 M; 3×100 ml), then water (4×100 ml). The organic phase was dried over magnesium sulphate, filtered and the solvent removed under reduced pressure to give the title compound as a yellow oil (72.9 g).

1. additionwas added dropwise over 30 minutes
2. temperaturemaintaining the internal temperature below 10° C.
3. additionDuring the addition a white precipitate
4. customformed
5. additionAfter addition
6. filtrationfiltered
7. washThe solid was washed with diethyl ether (200 ml)
8. washthe filtrate washed twice with saturated sodium bicarbonate solution (100 ml)
9. dry with materialThe organic phase was dried over magnesium sulphate
10. filtrationfiltered
11. customthe solvent removed under reduced pressure
12. customto give the crude product as an oil (79.4 g)
13. customTo remove
14. dissolutionthe oil was dissolved in diethyl ether
15. washwashed with sodium hydroxide solution (0.1 M; 3×100 ml)
16. dry with materialThe organic phase was dried over magnesium sulphate
17. filtrationfiltered
18. customthe solvent removed under reduced pressure