Réaction #62547

Équation de réaction

potassium fluoride

4-chloro-3-nitropyridine

potassium dihydrogen phosphate

→

4-fluoro-3-nitropyridine

Rendement 52.0%

Solvants

dimethylsulfoxide

Conditions de réaction

Traitement

1. 1
   workup.DISTILLATIONthe solvent reduced to half its volume by distillation under an atmosphere of nitrogen
2. 2
   Températurecooled
3. 3
   ExtractionThe resulting mixture was extracted with ethyl acetate
4. 4
   LavageThe organic phase was washed three times with water
5. 5
   Séchagebrine before being dried over anhydrous magnesium sulphate
6. 6
   AutreThe solvent was removed in vacuo

Mode opératoire

Anhydrous potassium fluoride (5.5 g, 93 mmol) was suspended in anhydrous dimethylsulfoxide (200 ml) and the solvent reduced to half its volume by distillation under an atmosphere of nitrogen. The resulting suspension was cooled to room temperature and 4-chloro-3-nitropyridine (14 g, 88 mmol) was added. The reaction mixture was stirred at 120° C. for three hours under an atmosphere of nitrogen, cooled and then poured into a saturated aqueous solution of potassium dihydrogen phosphate. The resulting mixture was extracted with ethyl acetate. The organic phase was washed three times with water and then brine before being dried over anhydrous magnesium sulphate. The solvent was removed in vacuo to yield as an oil, 4-fluoro-3-nitropyridine (6.5 g), (δ(CDCl3) 7.32 (1H, 4 lines), 7.86 (1H, t, J=5 Hz) and 8.29 (1H, d, J=9 Hz), represented by the structural formula: ##STR21##

Source