反应详情

The 2,6-difluoro-3-nitro benzoic acid (16 g, 79 mmol) prepared at Step 1 was added into a mixed solvent of dichloromethane and N,N-dimethylformamide and oxalyl chloride (14 mL, 158 mmol) was applied slowly. After stirring the reactant at room temperature for 18 hours and concentrating the solvent, the residuals were diluted with dichloromethane and N,N-dimethylformamide and the temperature was lowered to 0° C. Sodium azide (5.6 g, 87 mmol) was added gradually and slowly. After stirring at room temperature for 30 minutes, tert-butanol (40 mL) was applied. The reactant was refluxed and stirred for 3 hours. After the reaction, the solvent was vacuum concentrated. After the concentration, the residuals were washed with an aqueous solution of sodium hydrogen carbonate and salt water and extracted with ethylacetate, and the organic matter was concentrated and dried with sulfuric anhydride magnesium, and then refined by means of column chromatography, so that 20 g of the target compound, tert-butyl-2,6-difluoro-3-nitrophenylcarbamate (percentage yield: 93%), was obtained

1. concentrationconcentrating the solvent
2. additionthe residuals were diluted with dichloromethane and N,N-dimethylformamide
3. customwas lowered to 0° C
4. stirringAfter stirring at room temperature for 30 minutes
5. temperatureThe reactant was refluxed
6. stirringstirred for 3 hours
7. customAfter the reaction
8. concentrationconcentrated
9. concentrationAfter the concentration
10. washthe residuals were washed with an aqueous solution of sodium hydrogen carbonate and salt water
11. extractionextracted with ethylacetate
12. concentrationthe organic matter was concentrated
13. dry with materialdried with sulfuric anhydride magnesium