反应详情

温度

0 °C

Potassium ethoxide (505 g; 6 mole) was added to a solution of ethanol (710 ml) and diethyl ether (4.8 l) and the mixture was cooled to 0° C. 4-(Benzyloxy)-1-methyl-2-nitrobenzene (639.8 g; 3 mole) dissolved in diethyl oxalate (900 g; 6.16 mole) and toluene (1500 ml) was added slowly during 30 minutes. The reaction mixture was stirred for 3 hours at 0° C. and then allowed to stand cold over night. After 5 days at room temperature the reaction mixture was filtered and the filter cake was washed with diethyl ether (2 l). The cake was then treated with water (10 l), sodium hydroxide (5 M, 0.8 l) and extracted three times with diethyl ether (3×3 l). The water phase was cooled and acidified in two steps while stirring with hydrochloric acid:water (1:1, 0.9 l). First to pH 5 and the reaction mixture was then stirred for 1 hour before the acidification continued to pH 2. The reaction mixture was cooled in an ice:sodium chloride bath. Filtration after 1 hour gave 849.5 g (89.8%) of 3-(4-benzyloxy-2-nitrophenyl)-2-oxopropanoic acid.

1. waitto stand cold over night
2. filtrationAfter 5 days at room temperature the reaction mixture was filtered
3. washthe filter cake was washed with diethyl ether (2 l)
4. additionThe cake was then treated with water (10 l), sodium hydroxide (5 M, 0.8 l)
5. extractionextracted three times with diethyl ether (3×3 l)
6. temperatureThe water phase was cooled
7. stirringwhile stirring with hydrochloric acid:water (1:1, 0.9 l)
8. stirringFirst to pH 5 and the reaction mixture was then stirred for 1 hour before the acidification
9. temperatureThe reaction mixture was cooled in an ice
10. filtrationFiltration after 1 hour