反应详情

To a solution of methyl 4-chloro-2-methoxybenzoate (example 18d) (4.16 g, 20.8 mmol) in THF (120 mL) and NMP (12 mL) was added under inert atmosphere Iron (III) acetylacetonate (398 mg, 1.17 mmol) giving a red color. Then EtMgBr (29 ml of 1M solution in ether) was added dropwise under vigorous stirring. The mixture turned dark brown and then violet and then was stirred for 15 more min. The reaction was diluted with ether and quenched upon the addition of aq. HCl (1M, 50 mL). The crude product was extracted with ether and the combined organic layers were successively washed with water and brine, dried over MgSO4, filtered and evaporated. The residue was purified on silica gel (Eluent: 30% EtOAc in hexanes) to give methyl 4-ethyl-2-methoxybenzoate (2.01 g, 50%) as an oil. 1H NMR (300 MHz, dMSO): δ 1.20-1.22(t, 3H), 2.65-2.7 (dd, 2H), 3.9 (s, 3H), 6.8 (s, 1H), 6.97 (m, 1H), 7.7 (m, 1H).

1. customgiving a red color
2. customquenched upon the addition of aq. HCl (1M, 50 mL)
3. extractionThe crude product was extracted with ether
4. washthe combined organic layers were successively washed with water and brine
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. customevaporated
8. customThe residue was purified on silica gel (Eluent: 30% EtOAc in hexanes)