反应详情

温度

130 °C

To a stirred solution of 2-trifluoromethyl-pyridine 1-oxide (0.43 g, 2.43 mmol) in concentrated H2SO4 (2 mL) is added 70% HNO3 (1.6 mL) dropwise at 0° C. Reaction mixture is allowed to stir for 2 h at 130° C. After completion of reaction it is quenched with ice (˜200 g) and pH is adjusted 7 with solid K2CO3 (15-20 g) and extracted with EtOAc (3×20 mL). Organic part is washed with water, brine and dried over anhydrous MgSO4. Solution is concentrated under reduced pressure. The residue is purified by column chromatography (silica-gel, 100-200 mesh, eluent; 20% EtOAc in hexane) to afford 4-nitro-2-trifluoromethyl-pyridine 1-oxide (0.1 g, 20%).

1. customReaction mixture
2. customAfter completion of reaction it
3. customis quenched with ice (˜200 g) and pH
4. extractionextracted with EtOAc (3×20 mL)
5. washOrganic part is washed with water, brine
6. dry with materialdried over anhydrous MgSO4
7. concentrationSolution is concentrated under reduced pressure
8. customThe residue is purified by column chromatography (silica-gel, 100-200 mesh, eluent; 20% EtOAc in hexane)