反应详情

温度

5 °C

At 5° C., 5.9 g (0.043 mol) of sodium dihydrogen phosphate monohydrate in 70 ml of water, 20.5 g (0.181 mol) of 30% strength hydrogen peroxide solution and 27.3 g (0.241 mol) of 80% strength sodium chlorite solution were added in succession to a solution of 40.0 g (0.172 mol) of methyl 2,4-dichloro-3-formylbenzoate and 500 ml of acetonitrile. The reaction solution was stirred for 1 hour at 5° C. and for 12 hours at room temperature. Subsequently, the pH was adjusted to 1 with 10% strength hydrochloric acid and 500 ml of 40% strength sodium hydrogen sulfite solution were added. After stirring for 1 hour at room temperature, the aqueous phase was extracted three times with ethyl acetate and the combined organic phases were washed with 1.0 l of 10% strength sodium hydrogen sulfite solution and then dried. Removal of the solvent by distillation gave 40.0 g of methyl 2,4-dichloro-3-hydroxycarbonylbenzoate. (1H NMR (d6-DMSO, δ in ppm): 3.90 (s, 3H); 7.69 (d, 1H); 7.89 (d, 1H).)

1. additionwere added
2. stirringAfter stirring for 1 hour at room temperature
3. extractionthe aqueous phase was extracted three times with ethyl acetate
4. washthe combined organic phases were washed with 1.0 l of 10% strength sodium hydrogen sulfite solution
5. customdried
6. customRemoval of the solvent
7. distillationby distillation