4-Fluoro-2-(trifluoromethyl)aniline → 2-[N-(4-Fluoro-2-trifluoromethylphenyl)sulfamoyl]-acetic acid methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

5 g (27.64 mmol) of 4-fluoro-2-(trifluoromethyl)aniline is dissolved in 25 ml of dry pyridine, and the solution is cooled to 0° C. While maintaining the temperature, a solution of 4.82 g (27.4 mmol) of chlorosulfonylacetic acid methyl ester in 20 ml of dichloromethane is added dropwise to the cooled solution during the course of about 10 minutes. Then the mixture is stirred for 6 hours at room temperature. The reaction solution is then diluted with 100 ml of dichloromethane, the pyridine is extracted by shaking with 2N hydrochloride acid, the organic phase is dried over magnesium sulfate, filtered, and evaporated to dryness. The residue is crystallized from diethyl ether/hexane 1:1, thus obtaining 7.35 g (23.32 mmol)=84.35% of theory of a crystallized product, mp 84°14 86° C.

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