Carbonicanhydrase (CA) IX expression is increased upon hypoxia and has been proposed as a therapeutic target since it has been associated with poor prognosis, tumor progression and pH regulation. We report the synthesis and the pharmacological evaluation of a new class of human carbonicanhydrase (hCA) inhibitors, 4-(5-aryl-2-hydroxymethyl-pyrazol-1-yl)-benzenesulfonamides. A molecular modeling study