Pyridine → 4-[N-(4-fluoro-2-trifluoromethylphenyl)sulfamoyl]benzoic acid

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Reaction Conditions

Reaction Steps

2.21 g (10 mmol) of 4-chlorosulfonylbenzoic acid is suspended under exclusion of moisture in 30 ml of dichloromethane, the suspension is cooled to -5° C. and, at this temperature, a solution of 1.79 g (10 mmol) of 4-fluoro-2-(trifluoromethyl)aniline and 1 ml of pyridine in 20 ml of dichloromethane is added dropwise thereto. After this dropwise addition has been completed, the mixture is allowed to warm up to room temperature and is agitated for another 12 hours. The thus-produced precipitate is suctioned off and extracted with ether. This ether extract and the filtrate are evaporated together, and the residue is dissolved in dichloroethane. The solution is extracted three times with respectively 10 ml of saturated sodium bicarbonate solution. The combined aqueous extracts are acidified with 2N hydrochloric acid and the thus-precipitated product is removed by filtration. The filter residue is dried under vacuum at 50° C., thus obtaining 3.3 g (9.08 mmol)=90.84% of theory.

Provenance & Evidence