Abstract
Ethyl 2,3-dioxobutanoate-2-arylhydrazones 1 on treatment with [hydroxy(tosyloxy)iodo]benzene 2 at reflux temperature and followed by heating in the presence of N-ethyldiisopropylamine afforded the cyclized ethyl 1-aryl-4-hydroxy-1H-3-pyrazolecarboxylates 4 in good yield.