Preparation of 2-(1-phenyl-1H-pyrazol-5-yl)benzenesulfonamides from polylithiated C(α),N-phenylhydrazones and methyl 2-(aminosulfonyl)benzoate

Select C(alpha),N-phenylhydrazones were dilithiated in excess lithium diisopropylamide followed by condensation with methyl 2-(aminosulfonyl)benzoate and acid cyclization to afford new pyrazol-benzenesulfonamides, 2-(1-phenyl-1H-pyrazol-5-yl)benzenesulfonamides.