4-Toluenesulfonyl chloride → 1-(toluene-4-sulfonyl)-1H-pyrazole-3-carbaldehyde

Participants

Reaction Steps

To a solution of 1H-pyrazole-3-carbaldehyde (3.00 g, 31.22 mmol) in THF was added 60% NaH (1.64 g, 41.00 mmol) in mineral oil. After 20 minutes, p-toluenesulfonyl chloride (7.82 g, 41.00 mmol) was added. After 2 hours, the reaction was diluted with water and extracted with EtOAc. The combined organic layers were washed with brine, dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica gel chromatography eluting with a gradient of 10-50% EtOAc in heptane. The major fractions were combined and the solvent was concentrated in vacuo to afford (1-(toluene-4-sulfonyl)-1H-pyrazole-3-carbaldehyde) as a white solid.

Provenance & Evidence