Reaktion #1473117

Reaktionsgleichung

citric acid

methylsulfonyl chloride

sodium hydroxide

3-(5-amino-4-chloro-2-fluorophenyl)-1-methyl-6-trifluoromethyl-2(1H)-pyridone

triethylamine

→

desired product

Ausbeute 72.0%

3-(4-chloro-2-fluoro-5-methylsulfonylaminophenyl)-1-methyl-6-trifluoromethyl-2(1H)-pyridone

Ausbeute 72.0%

Lösungsmittel

ammonium chloride

dichloromethane

water

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturunder cooling with ice
2. 2
   ExtraktionThe mixture was extracted with ethyl acetate
3. 3
   WaschenAfter washing with water
4. 4
   Trocknena saturated sodium chloride aqueous solution, the organic layer was dried over anhydrous magnesium sulfate
5. 5
   workup.DISTILLATIONEthyl acetate was distilled off under reduced pressure
6. 6
   SonstigeThen, the obtained crude crystals of the bissulfone compound
7. 7
   workup.STIRRINGby stirring for 1 hour
8. 8
   Extraktionextracted with ethyl acetate
9. 9
   WaschenAfter washing with water
10. 10
    Trocknenthe organic layer was dried over anhydrous magnesium sulfate Ethyl acetate
11. 11
    workup.DISTILLATIONwas distilled off under reduced pressure
12. 12
    SonstigeThen, the obtained crude crystals
13. 13
    Waschenwere washed with n-hexane

Vorschrift

0.9 g (2.8 mmol) of 3-(5-amino-4-chloro-2-fluorophenyl)-1-methyl-6-trifluoromethyl-2(1H)-pyridone and 0.6 g (5.9 mmol) of triethylamine were dissolved in 20 ml of dichloromethane, and 0.7 g (6.1 mmol) of methylsulfonyl chloride was dropwise added thereto under cooling with ice. The mixture was stirred at room temperature for 2 hours and then diluted with an aqueous ammonium chloride solution. The mixture was extracted with ethyl acetate. After washing with water and a saturated sodium chloride aqueous solution, the organic layer was dried over anhydrous magnesium sulfate. Ethyl acetate was distilled off under reduced pressure. Then, the obtained crude crystals of the bissulfone compound were dissolved in 25 ml of ethanol, and 10 ml (5.0 mmol) of a 0.5N sodium hydroxide aqueous solution was added at room temperature, followed by stirring for 1 hour. The mixture was poured into water, acidified with citric acid and extracted with ethyl acetate After washing with water, the organic layer was dried over anhydrous magnesium sulfate Ethyl acetate was distilled off under reduced pressure. Then, the obtained crude crystals were washed with n-hexane to obtain 0.80 g (yield: 72%) of the desired product. Melting point: 113-114° C.

Quelle