反应详情

温度

70 °C

Sodium hydride (55% dispersion in mineral oil, 603 mg, 13.8 mmol) was added to a solution of ethyl glycolate (1.43 g, 13.8 mmol) in 1,4-dioxane, and the reaction mixture was heated at 70° C. for 1 h, then 5-bromo-2-chloro-3-nitropyridine (Eur. Pat. Appl. EP 122109 (1984); 1.64 g, 6.91 mmol) was added, and stirring was continued at 70° C. for 1 h and at room temperature for 16 h. The reaction mixture was then neutralized with sat. aq. sodium hydrogencarbonate solution and extracted three times with dichloromethane. The organic layers were pooled, dried (Na2SO4), and evaporated. Chromatography (SiO2, hexane-ethyl acetate gradient) furnished (5-bromo-3-nitropyridin-2-yloxy)-acetic acid ethyl ester (1.03 g, 49%). Light yellow liquid, MS (ISP)=305.1 (M+H)+.

1. extractionextracted three times with dichloromethane
2. dry with materialdried (Na2SO4)
3. customevaporated