Sulfuryl chloride → N-{2,4-difluoro-3-[1-ethyl-4-(pyridin-4-yl)-1H-pyrazol-3-yl]phenyl}-2,5-difluorobenzenesulfonamide

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Reaction Conditions

Reaction Steps

3-(1-Ethyl-4-pyridin-4-yl-1H-pyrazol-3-yl)-2,4-difluoro-phenylamine (1.146 g, 3.816 mmol) was dissolved in anhydrous pyridine (30 M) under nitrogen atmosphere and cooled to 0° C. 2,5-Difluoro-benzenesulfonyl chloride (0.513 mL, 3.816 mmol, 1 eq) was added and the mixture was allowed to stir at the same temperature. Further additions of sulfonyl chloride (for a total amount of 0.650 mL) were needed to drive the reaction to completion. The reaction mixture was kept at 0° C. overnight and then it was allowed to reach room temperature. The solvent was removed under reduced pressure and the residue was dissolved in ethyl acetate and washed with NaHCO3 saturated aqueous solution. The organic layer was dried over anhydrous sodium sulfate and evaporated to dryness. The crude product was slurried in methanol at 50° C. for 10 minutes and the solid was filtered and washed with ethyl ether. After drying at 40° C. for 5 hours 1.13 g of the title compound were obtained as a white solid (62% yield).

Provenance & Evidence