Water → 5-Chloro-N-{2-ethyl-1-[1-(4-hydroxybenzyl)-1H-pyrazol-5-yl]butyl}thiophene-2-sulfonamide

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Reaction Steps

To 5-chloro-N-{2-ethyl-1-[1-(4-methoxybenzyl)-1H-pyrazol-5-yl]butyl}thiophene-2-sulfonamide (57.0 mg, 0.121 mmol) in CH2Cl2 (3 mL) at −78° C. was added a solution of boron tribromide (1 M in CH2Cl2, 0.40 mL, 0.40 mmol) dropwise. The reaction mixture was warmed to room temperature gradually over several hours and allowed to stir overnight. Water (10 mL) was added slowly to the mixture. It was then extracted with EtOAc (3×20 mL), dried (Na2SO4) and concentrated. Column chromatography (EtOAc/hex, 3:7) provided 40 mg (72%) of 5-chloro-N-{2-ethyl-1-[1-(4-hydroxybenzyl)-1H-pyrazol-5-yl]butyl}thiophene-2-sulfonamide as a white solid (mp=90-92° C.).

Provenance & Evidence