反応 #955937

反応方程式

EtMgBr

methyl 4-chloro-2-methoxybenzoate

→

methyl 4-ethyl-2-methoxybenzoate

収率 50.0%

溶媒

THF

NMP

ether

反応条件

後処理

1. 1
   その他giving a red color
2. 2
   その他quenched upon the addition of aq. HCl (1M, 50 mL)
3. 3
   抽出The crude product was extracted with ether
4. 4
   洗浄the combined organic layers were successively washed with water and brine
5. 5
   乾燥dried over MgSO4
6. 6
   ろ過filtered
7. 7
   その他evaporated
8. 8
   その他The residue was purified on silica gel (Eluent: 30% EtOAc in hexanes)

実験手順

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).

出典