反应详情

温度

-15 °C

A vigorously stirred suspension of 4-fluoro-3-nitroaniline (25 g, 0.16 mol) in conc. hydrochloric acid (125 ml) was cooled to −15° C. A solution of sodium nitrite (12.1 g, 0.18 mol) in water (25 ml) was added drop-wise keeping the temperature at −15° C. Following the addition the mixture was stirred for 15 min whereafter a solution of potassium iodide (33.4 g, 0.2 mol) in water (65 ml) was added over 45 min. At the end of the addition the mixture was stirred for additionally 30 min at ambient temperature. Aqueous sodium sulfite (1M) was added to remove iodine and the resulting mixture was extracted thrice with diethyl ether. The combined extracts were successively washed with ice-cold aqueous sodium hydroxide (1M) and brine, dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel, using a mixture of ethyl acetate and petroleum ether (1:9 v/v) as the eluent, to yield the desired product (30.3 g, 71%) as a yellowish oil.

1. customat −15° C
2. additionthe addition the mixture
3. additionwas added over 45 min
4. additionAt the end of the addition the mixture
5. customto remove iodine
6. extractionthe resulting mixture was extracted thrice with diethyl ether
7. washThe combined extracts were successively washed with ice-cold aqueous sodium hydroxide (1M) and brine
8. dry with materialdried over sodium sulfate
9. concentrationconcentrated under reduced pressure
10. customThe residue was purified by column chromatography on silica gel
11. additiona mixture of ethyl acetate and petroleum ether (1:9 v/v) as the eluent