反应详情

温度

0 °C

Ethyl 2-(4-chlorophenoxy)acetoacetate (90.3 g, 0.353 mol) was added dropwise to sulfuric acid (240 ml) stirred at 0° C. The resulting suspension was stirred at 0° C for 3.5 hours, poured onto crushed ice and the mixture stirred for 0.5 hours. The mixture was extracted with toluene and the organic phase was washed with 5% sodium bicarbonate and water. The organic phase was dried with magnesium sulfate, filtered and concentrated. The crude product was recrystallized from cyclohexane to give 54.5 g (65%) of ethyl 5-chloro-3-methyl-2-benzofurancarboxylate: mp 80°-82° C.

1. stirringThe resulting suspension was stirred at 0° C for 3.5 hours
2. additionpoured
3. customonto crushed ice
4. stirringthe mixture stirred for 0.5 hours
5. extractionThe mixture was extracted with toluene
6. washthe organic phase was washed with 5% sodium bicarbonate and water
7. dry with materialThe organic phase was dried with magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customThe crude product was recrystallized from cyclohexane