反应详情

At 0° C., 0.258 ml (2.7 mmol, 1.0 eq.) of tert-butanol was added to a solution of 500 mg (2.7 mmol) of 2-fluoro-4-nitrobenzoic acid and 1.03 g (5.4 mmol, 2.0 eq.) of para-toluenesulphonyl chloride in 5.4 ml of pyridine, the mixture was stirred for 60 min and a further 0.258 ml (2.7 mmol, 1.0 eq.) of tert-butanol was added. The reaction mixture was stirred for another 18 h and concentrated under reduced pressure. Saturated aqueous sodium bicarbonate solution and ethyl acetate were added to the residue. After phase separation, the aqueous phase was extracted with ethyl acetate. The combined organic phases were washed with saturated aqueous sodium chloride solution, dried (sodium sulphate), filtered and concentrated under reduced pressure. The crude product was then purified by normal phase chromatography (mobile phase: cyclohexane/ethyl acetate 14%-20% mixtures). Yield: 524 mg (75% of theory).

1. stirringThe reaction mixture was stirred for another 18 h
2. concentrationconcentrated under reduced pressure
3. additionSaturated aqueous sodium bicarbonate solution and ethyl acetate were added to the residue
4. customAfter phase separation
5. extractionthe aqueous phase was extracted with ethyl acetate
6. washThe combined organic phases were washed with saturated aqueous sodium chloride solution
7. dry with materialdried (sodium sulphate)
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customThe crude product was then purified by normal phase chromatography (mobile phase: cyclohexane/ethyl acetate 14%-20% mixtures)