反应详情

To a 1-chloro-3,4-difluorobenzene (25 g, 0.17 mol) cooled to 0° C. was added fuming nitric acid (50 mL) dropwise over 30 min. The orange solution was warmed to room temperature and stirred for 2 h. The solution was poured slowly over ice and the resultant mixture extracted with diethyl ether. The diethyl ether layers were washed with brine, dried (Na2SO4), filtered and concentrated in vacuo to give 26 g (80%) of 1-chloro-4,5-difluoro-2-nitro-benzene: Crude 1H NMR (400 MHz, CDCl3): δ 7.88 (dd, J=9.3, 7.6 Hz, 1H), 7.43 (dd, J=9.3, 7.1 Hz, 1H). The crude material was pure enough to carry on to the next step.

1. additionThe solution was poured slowly over ice
2. extractionthe resultant mixture extracted with diethyl ether
3. washThe diethyl ether layers were washed with brine
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated in vacuo