反应详情

A suspension of Zn powder (31.5 g, 0.48 mol) in tetrahydrofuran (300 ml) was boiled under reflux, and then it was added thereto a few drops of ethyl 2-bromo-3-methylbutanoate to initiate the reaction. After 45 mn under reflux and under magnetic stirring, it was added thereto 3,5-dimethylphenylethanenitrile (13.2 g, 91 mmol), and then, dropwise, the remainder of ethyl 2-bromo-3-methylbutanoate (in total 19.1 g, 91 mmol). The ebullition was maintained for 15 mn, the mixture was then cooled, and then it was added thereto tetrahydrofuran (500 ml) and a 50% aqueous potassium carbonate solution (100 ml). After 45 mn under vigorous stirring, the organic phase was separated by decantation and the aqueous phase was washed with tetrahydrofuran (2×100 ml). The collected organic phases were treated with 10% aqueous hydrochloric acid solution (300 ml) for 45 mn. After elimination of tetrahydrofuran by distillation under reduced pressure, the residue was taken again with dichloromethane (300 ml), and the organic phase was washed with a saturated sodium monohydrogenocarbonate solution (100 ml), dried over magnesium sulfate and concentrated. The distillation of the residue (134° C., 10−1 mmHg) gave ethyl 3-methyl-2-(3,5-dimethylphenylacetyl)butanoate (13.2 g, 52%).

1. temperatureunder reflux
2. additionit was added
3. customthe reaction
4. temperatureAfter 45 mn under reflux and under magnetic stirring, it
5. additionwas added
6. temperatureThe ebullition was maintained for 15 mn
7. temperaturethe mixture was then cooled
8. additionit was added
9. customAfter 45 mn under vigorous stirring, the organic phase was separated by decantation
10. washthe aqueous phase was washed with tetrahydrofuran (2×100 ml)
11. additionThe collected organic phases were treated with 10% aqueous hydrochloric acid solution (300 ml) for 45 mn
12. distillationAfter elimination of tetrahydrofuran by distillation under reduced pressure
13. washthe organic phase was washed with a saturated sodium monohydrogenocarbonate solution (100 ml)
14. dry with materialdried over magnesium sulfate
15. concentrationconcentrated
16. distillationThe distillation of the residue (134° C., 10−1 mmHg)