反应详情

A mixture of methyl-4-bromo-3-methylbenzoate (5.7 g, 24.88 mmol), lithium aluminum hydride (29 mL, 29 mmol, 1 M solution in tetrahydrofuran) and tetrahydrofuran (100 mL) is stirred in ice/water for 1 hr. The reaction is quenched with aqueous hydrochloric acid (50 mL, 1 M). The product is extracted into ethyl acetate (3×100 mL). The combined extracts are dried over anhydrous magnesium sulfate, filtered and concentrated. The crude product is taken up in propionitrile (100 mL). Methylacrylate (10 mL, 121.5 mmol), palladium acetate (1.12 g, 5 mmol), tri-o-tolylphosphine (3.0 g, 10 mmol), and N,N-diisopropyl ethylamine (8.7 mL, 50 mmol) are sequentially added and the resulting reaction mixture is heated to 110 deg C. 3 hr. The mixture is concentrated, and the residue diluted with aqueous hydrochloric acid (100 mL, 1M). The product is extracted with dichloromethane (2×100 mL) and ethyl acetate (100 mL). The combined extracts are dried over anhydrous magnesium sulfate, filtered, concentrated, and purified via silica chromatography eluting with 7:3 hexanes:ethyl acetate to 1:1 hexanes:ethyl acetate to afford the pure product as a yellow oil, 4.7 g, 91%. MS M++1 207. The structure is confirmed by 1H NMR spectroscopy.

1. customThe reaction is quenched with aqueous hydrochloric acid (50 mL, 1 M)
2. extractionThe product is extracted into ethyl acetate (3×100 mL)
3. dry with materialThe combined extracts are dried over anhydrous magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customthe resulting reaction mixture
7. temperatureis heated to 110 deg C
8. custom3 hr
9. concentrationThe mixture is concentrated
10. additionthe residue diluted with aqueous hydrochloric acid (100 mL, 1M)
11. extractionThe product is extracted with dichloromethane (2×100 mL) and ethyl acetate (100 mL)
12. dry with materialThe combined extracts are dried over anhydrous magnesium sulfate
13. filtrationfiltered
14. concentrationconcentrated
15. custompurified via silica chromatography
16. washeluting with 7:3 hexanes