Boron tribromide → 2-Fluoro-5-nitrophenol

Participants

Reaction Steps

116 ml (116 mmol) of boron tribromide (1 molar solution in dichloromethane) are added dropwise at −10° C. over a period of 1 h to a solution of 5.00 g (29.2 mmol) of 1-fluoro-2-methoxy-4-nitrobenzene at such a rate that the temperature does not exceed −5° C. The solution is left at 0° C. for 5 h, then added slowly to 600 ml of ice-water and diluted with 100 ml of ethyl acetate. After phase separation, the aqueous phase is extracted twice with ethyl acetate. The combined organic phases are dried over sodium sulfate. After filtration, the solvents are removed under reduced pressure. The residue is purified by chromatography on silica gel (10:1 cyclohexane/ethyl acetate). This affords 1.45 g (30% of theory) of the desired compound.

Provenance & Evidence