反应详情

Into a solution of 4,5-difluoro-2-nitroaniline (20 g) in acetic acid (200 ml) was boubled chlorine gas at 13° to 15° C. during 45 minutes. The reaction mixture was poured into ice water (500 ml) and extracted with dichloromethane. The organic layer was washed with 6% aqueous sodium carbonate and with water successively, dried over anhydrous sodium sulfate and then concentrated. The residue was purified with silica gel chromatography eluting with dichloromethane-n-hexane (1:4) and further recrystallized from hexane to give the title compound (2.91 g) as yellow needles, mp 86°-88° C.

1. customat 13° to 15° C.
2. customduring 45 minutes
3. extractionextracted with dichloromethane
4. washThe organic layer was washed with 6% aqueous sodium carbonate and with water successively
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationconcentrated
7. customThe residue was purified with silica gel chromatography
8. washeluting with dichloromethane-n-hexane (1:4)
9. customfurther recrystallized from hexane