反应详情

To a solution of 4-(trifluoromethoxy)benzonitrile (2.0 g, 10.6 mmol) in EtOH (20 mL), TEA (53 g, 53.0 mmol) and NH2OH.HCl (3.6 g, 26.5 mmol) were added in sequence. The mixture was refluxed for 4 h, cooled to RT, and concentrated under reduced pressure. The residue was diluted with H2O (20 mL), and extracted with EtOAc (20 mL×3). The combined organic layers were washed with H2O (1×10 mL) and brine (1×10 mL), dried over Na2SO4, filtered and concentrated to afford the crude N-hydroxy-4-(trifluoromethoxy)benzimidamide (2.0 g, 85%), which was directly used for next reaction without further purification. MS (ES+) C8H7F3N2O2 requires: 220, found: 221 [M+H]+.

1. temperatureThe mixture was refluxed for 4 h
2. concentrationconcentrated under reduced pressure
3. additionThe residue was diluted with H2O (20 mL)
4. extractionextracted with EtOAc (20 mL×3)
5. washThe combined organic layers were washed with H2O (1×10 mL) and brine (1×10 mL)
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated