Pyrazole → 2-Chloro-4-methylsulfonyl-3-(pyrazol-1-yl)benzoic Acid

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Reaction Conditions

Reaction Steps

Pyrazole (210 mg, 3.09 mmol) was added to 190 mg (4.75 mmol) of 60 percent oil dispersed sodium hydride suspended in 7 mL of dry dimethylformamide. After the gas evolution had subsided, 500 mg (1.98 mmol) of 2-chloro-3-fluoro-4-methylsulfonylbenzoic acid was added and the mixture was stirred at 50° C. overnight. The mixture was then concentrated by evaporation under reduced pressure and the residue was partitioned between ethyl acetate and 1N aqueous hydrochloric acid. The aqueous phase was extracted with ethyl acetate. The organic phases were combined and extracted with dilute aqueous sodium bicarbonate solution. The aqueous extract was acidified with 1N aqueous hydrochloric acid and extracted with dichloromethane. The organic extract was concentrated by evaporation under reduced pressure. The crystalline residue obtained was purified by rinsing with ethyl acetate to obtain 540 mg (91 percent of theory) of the title compound as a white powder.

Provenance & Evidence