Potassium Iodide → 1-Fluoro-4-iodo-2-nitrobenzene

Participants

Reaction Conditions

Reaction Steps

A suspension of 4-fluoro-3-nitroaniline (100 g, 0.64 mol) in conc. hydrochloric acid (500 ml) is cooled to -20° C. A solution of sodium nitrite (48.6 g, 0.7 mol) in 100 ml of water is added with stirring, keeping the temperature below -15° C. Following the addition the mixture is stirred for 45 min. at -20-(-15)° C. To the resulting solution a solution of potassium iodide (132.8 g, 0.8 mol) in 260 ml of water is added at such a rate that the temperature is kept below 0° C. The mixture is stirred until the evolution of nitrogen has ceased. Aqueous sodium sulfite (200 ml, 1 M) is added and the mixture is extracted with diethyl ether. The etheral extract is washed twice with ice-cold 1 M aqueous sodium hydroxide and twice with brine. Finally the extract is dried over magnesium sulfate, concentrated and purified by column-chromatography on silica gel using a mixture of ethyl acetate and petroleum ether (1:9) as the eluent. 1cis isolated as an oil, which crystallizes in the refrigerator. Yield: 132.6 g (78%).

Provenance & Evidence