Sulfuryl chloride → 2-(1H-Pyrazol-1-yl)benzenesulfonyl chloride

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Reaction Steps

To a solution of 52 g of 1-(2-bromophenyl)pyrazole in 230 ml of diethyl ether under a nitrogen atmosphere and cooled at -70° C. was added dropwise 175 ml of a 1.6M solution of n-butyl lithium in hexane. The suspension was allowed to warm from -70° C. to -25° C. on its own, then a solution of 37 ml of sulfuryl chloride in 69 ml of hexane was added dropwise at -25° to -20° C. After allowing the suspension to warm to room temperature, the suspension was stirred for 5 hours, then filtered to yield 38 g of crude 2-(1H-pyrazol-1-yl)benzenesulfonyl chloride which was contaminated with inorganic salts.

Provenance & Evidence