Nitric Acid → 2,4-Difluoro-5-nitroaniline
Reaction equation
[F:1][C:2]1[CH:8]=[C:7]([F:9])[CH:6]=[CH:5][C:3]=1[NH2:4].S(=O)(=O)(O)O.[N+:15]([O-])([OH:17])=[O:16]>>[F:1][C:2]1[CH:8]=[C:7]([F:9])[C:6]([N+:15]([O-:17])=[O:16])=[CH:5][C:3]=1[NH2:4]Participants
4
Conditions
- Temperature
- 5 °C
Procedure
To a solution of 2,4-difluoroaniline (0.394 mL, 3.87 mmol) in concentrated sulfuric acid (5 mL, 94 mmol) at 0° C. was added drop wise nitric acid (0.272 mL, 375 mg, 3.87 mmol) in 20 min. The reaction was stirred under 5° C. for 30 min. The reaction mixture was poured in ice cold water and extracted with ether. Organic layer was washed with saturated NaHCO3 solution, dried and evaporated to give 2,4-difluoro-5-nitroaniline 71 (467 mg, 69.3%). NMR (400 MHz, CDCl3) 3.91 (br s, 2H), 6.98 (t, J=10.2 Hz, 1H), 7.51 (dd, J=8.6 Hz and 7.0 Hz, 1H).