反应详情

温度

0 °C

To 265 mg (6.78 mmol) potassium in 20 mL absolute diethylether, 2.5 mL ethanol were slowly added. The mixture is cooled to 0° C. and a solution of 720 mg (3.39 mmol) 2-(2-Methoxy-ethoxy)-4-methyl-5-nitro-pyridine in 2.5 mL of absolute diethylether and 0.5 mL ethanol were added. 3.966 g (27.14 mmol) oxalic acid diethylester in 15 mL toluene were added tropwise over 45 min. The reaction mixture was stirred at room temperature for 4 h. The precipitate was filtered, washed with diethyl ether/n-heptane 1/1 and dried in vacuo. 1.4 g of 3-[2-(2-Methoxy-ethoxy)-5-nitro-pyridin-4-yl]-2-oxo-propionic acid ethylester potassium salt were isolated as a red solid and used in the next step without further purification.

1. filtrationThe precipitate was filtered
2. washwashed with diethyl ether/n-heptane 1/1
3. customdried in vacuo