反应详情

In nitrogen atmosphere, to ethyl 2-ethoxy-4-fluorobenzoate as synthesized in above Production Example 31, 6.51 g, conc. sulfuric acid 34 mL was added under cooling with ice. Potassium nitrate 3.26 g was further added little by little, under cooling with salt-ice, followed by stirring for 3.4 hours under cooling with ice. The reaction liquid was poured in ice water, and the precipitated crystals were recovered by filtration and washed with water. Recrystallizing the crystals from tert-butyl methyl ether-hexane mixed solvent, 4.49 g of the title compound was obtained.

1. additionwas added
2. temperatureunder cooling with ice
3. temperatureunder cooling with ice
4. customThe reaction liquid
5. filtrationthe precipitated crystals were recovered by filtration
6. washwashed with water
7. customRecrystallizing the crystals from tert-butyl methyl ether-hexane mixed solvent