Nitric Acid → 1,2-Difluoro-4-nitrobenzene

Participants

Reaction Conditions

Reaction Steps

This material is prepared as described by R. W. Taft, G. B. Klingensmith, and S. Ehrenson (J.Am. Chem.Soc., 87, 3620 (1965)). To a stirred mixture of 5.0 ml of concentrated nitric acid and 13.9 ml of concentrated sulfuric acid cooled to -12° C. is added 9.7 g (0.085 mole) of 1,2-difluorobenzene. A slight exotherm is observed and the mixture is cooled to -20° C. whereupon it solidifies. The mixture is stirred for forty-five minutes at -5° to 0° and is then allowed to warm slowly to room temperature. After one hour the mixture is poured onto ice, and the mixture extracted with diethyl ether (3×75 ml). The combined ether extracts are washed with water, 10% aqueous Na2CO3, and water again. The ether solution is dried (MgSO4) and concentrated in vacuo without external heating to give the crude product (11.9 g), which is distilled (kugelrohr apparatus) to give 10.2 g of colorless liquid. The nmr spectrum of this material is consistent with the structure.

Provenance & Evidence