反应详情

Fuming nitric acid (25 ml) was stirred with cooling (ice/water bath) and 3,4-difluorophenylacetonitrile (5 g, 32.7 mmol) was added dropwise. The mixture was left to stir for 15 h and was then poured onto ice. The mixture was neutralised with sodium hydrogen carbonate and extracted with dichloromethane. The combined organic phases were dried (MgSO4), filtered and concentrated under reduced pressure to give 2(2'-nitro-4',5'-difluorophenyl)-acetonitrile as a yellow oil which was immediately in ethanol/acetic acid (19:1) and hydrogenated over 10% palladium on charcoal at 65 p.s.i. The reaction mixture was filtered and concentrated under reduced pressure. The oily residue was taken up in ethyl acetate and washed with aqueous sodium hydrogen carbonate solution. The combined organic phases were dried (MgSO4), filtered and concentrated under reduced pressure to give 5,6-Difluoroindole as a yellow solid. Mass spectroscopy showed 154.1 (MH+).

1. additionwas added dropwise
2. waitThe mixture was left
3. additionwas then poured onto ice
4. extractionextracted with dichloromethane
5. dry with materialThe combined organic phases were dried (MgSO4)
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure