反应详情

温度

50 °C

A 25 ml three-neck flask with magnetic stirrer, reflux condenser and dropping funnel is initially charged with 20 ml of tetrahydrofuran (THF) which has been dried over molecular sieve, and 0.36 ml of water. The mixture is heated to 50° C. while passing argon through for a few minutes, and then cooled again to room temperature. Still under argon, the following are now added: 17.2 mg [0.03 mmol=0.3 mol %] of bis(dibenzylideneacetone)palladium, 27.4 mg of P(o-tolyl)3 [0.09 mmol], 2.91 g of potassium fluoride (dried over P2O5 at 140° C.), 1.5 g [10 mmol] of 2,6-dimethylphenylboronic acid and 2.56 g [15 mmol] of ethyl bromoacetate. This mixture is stirred under reflux in a gentle argon stream for 24 hours. Then it is filtered through a little Celite, and the filtercake is washed three times with 20 ml each time of ethyl acetate. The combined filtrates are extracted by shaking with 20 ml of 1 N hydrochloric acid. The aqueous phase is re-extracted twice with 20 ml of ethyl acetate each time. The combined organic phases are then washed with 20 ml of saturated aqueous NaCl solution, dried and concentrated. This gives 1.59 g of an oil which, according to GC-MS, as well as 10.7 area % of m-xylene, contains 56.6 area % of ethyl 2,6-dimethylphenylacetate. This corresponds to a yield of 46.8% of theory.

1. temperatureA 25 ml three-neck flask with magnetic stirrer, reflux condenser
2. dry with materialhas been dried over molecular sieve, and 0.36 ml of water
3. customthrough for a few minutes
4. temperaturecooled again to room temperature
5. additionStill under argon, the following are now added
6. temperatureunder reflux in a gentle argon
7. filtrationThen it is filtered through a little Celite
8. washthe filtercake is washed three times with 20 ml each time of ethyl acetate
9. extractionThe combined filtrates are extracted
10. stirringby shaking with 20 ml of 1 N hydrochloric acid
11. extractionThe aqueous phase is re-extracted twice with 20 ml of ethyl acetate each time
12. washThe combined organic phases are then washed with 20 ml of saturated aqueous NaCl solution
13. customdried
14. concentrationconcentrated