Benzenesulfonyl chloride → 4-(5-benzenesulfonylamino-1-phenyl-1H-pyrazole-3-yl)-benzoic acid methyl ester

Participants

Reaction Steps

A solution of benzenesulfonyl chloride (0.913 ml, 7.15 mmol) in dichloromethane (7 ml) was added slowly to a solution of 4-(5-amino-1-phenyl-1H-pyrazole-3-yl)-benzoic acid methyl ester (1.5 g, 5.11 mmol) in pyridine (20 ml) at 5° C. The resulting solution was stirred at room temperature for 18 h. The solvent was evaporated in vacuo and the products were separated by flash chromatography, on silica gel, using 0 to 2% methanol in dichloromethane as the eluant, to yield 4-(5-benzenesulfonylamino-1-phenyl-1H-pyrazole-3-yl)-benzoic acid methyl ester, and 4-{5-[bis(Benzenesulfonyl)amino]-1-phenyl-1H-pyrazole-3-yl}-benzoic acid methyl ester.

Provenance & Evidence