反应详情

In a flask was dissolved 3,4-Difluorophenol (3.10 g, 23.7 mmole) in acetic acid (15 ml). To the stirred solution was added dropwise a solution of fuming HNO3 (1.25 g, 29.7 mmole) in acetic acid (6 ml). The temperature was kept under 50° C. during the entire addition. After completed addition, the mixture was stirred for another hour. The reaction mixture was then poured onto ice-water, giving precipitation of a yellowish solid. The solid was collected by filtration, and dried. The solid was purified on silica (Heptane:EtOAc 5:1), giving the sub-title compound (2.05 g, 50%) as a yellow oil, which crystallizes on standing.

1. additionThe temperature was kept under 50° C. during the entire addition
2. additionaddition
3. additionThe reaction mixture was then poured onto ice-water
4. customgiving
5. customprecipitation of a yellowish solid
6. filtrationThe solid was collected by filtration
7. customdried
8. customThe solid was purified on silica (Heptane:EtOAc 5:1)