Ammonia → 1,3-dimethyl-1H-pyrazole-4-sulfonamide

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Reaction Conditions

Reaction Steps

59 g (0.615 mmol) of 1,3-dimethylpyrazole is added slowly to 300 g (2.5 mmol) of chlorosulfonic acid at 0° C. The reaction is warmed to 90° C. for 3 hours, cooled and poured onto 500 g of ice. The aqueous solution is extracted with 3×100 ml of ether. The organic extract is dried over anhydrous sodium sulfate and filtered. The ether solution is added dropwise to a solution of 55 grams of anhydrous ammonia (2.5 mmol) in 250 ml of ether. After standing overnight, water is added and the layers separated. The aqueous solution is extracted with ethyl acetate, the organic solutions combined and dried over anhydrous sodium sulfate. After removal of the drying agent, the solvent is removed in vacuo giving 20.5 g of product, m.p. =97°-105° C.

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