Sulfuryl chloride → 4-Chloro-1-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl)-5-methylcarbonylaminopyrazole

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Reaction Steps

A solution of 0.80 gram (0.0023 mole) of 1-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl)-5-methylcarbonylaminopyrazole (Step C of Example 1) in 25 mL of methylene chloride was cooled to -5° C. Sulfuryl chloride (9.35 gram, 0.0026 mole) was added dropwise during a two minute period. After the addition was complete, the reaction mixture was allowed to warm to room temperature and was stirred for 1.5 hours. The reaction mixture was diluted with methylene chloride and washed in succession with an aqueous, saturated sodium bicarbonate solution and water. The organic phase was evaporated under reduced pressure to yield 0.82 gram of 4-chloro-1-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl)-5-methylcarbonylaminopyrazole as a white solid, m.p. 45°-47° C. The nmr spectrum was consistent with the proposed structure.

Provenance & Evidence