Dimethyl Sulfoxide → 2,2,3,3-Tetrafluoro-5-nitrobenzofuran

Participants

Reaction Steps

Into a pressure bottle were placed 3.0 g (0.0085 mole) 3-chloro-4-(2-bromo-1,1,2,2-tetrafluoroethoxy)nitrobenzene, 2.7 g (0.043 mole) copper powder (200 mesh), and 40 ml of dimethyl sulfoxide. The pressure bottle was sealed, and the reaction mixture stirred at 190°-195° C. for 6.5 hours. The pressure bottle was cooled to room temperature, opened, and the contents poured into a separatory funnel. Approximately 200 ml of water was added to the separatory funnel, and the mixture was extracted with three 150 ml portions of diethyl ether. The extracts were combined and washed first with 200 ml of a 2N hydrochloric acid solution, then with 200 ml of a saturated aqueous sodium chloride solution. The washed extract was dried over anhydrous magnesium sulfate and filtered. The solvent was evaporated under reduced pressure, leaving an oil. The reaction described above was repeated one additional time. The residual oils from the two experiments were combined and upon standing formed crystals of 2,2,3,3-tetrafluoro-2,3-dihydro-5-nitrobenzofuran.

Provenance & Evidence