Polysubstituted pyrazoles, part 6. Synthesis of some 1-(4-chlorophenyl)-4-hydroxy-1H-pyrazol-3-carbonyl derivatives linked to nitrogenous heterocyclic ring systems as potential antitumor agents

The synthesis of two novel series of 1-(4-chlorophenyl)-4-hydroxy-1H-pyrazoles linked to either polysubstituted 1H-pyrazole counterparts through a carbonyl bridge, or to some biologically-active nitrogenous heterocycles by an amide linker, is described. According to the National Cancer Institute (NCI) in vitro disease-oriented antitumor screening protocol, six compounds 2, 3, 6, 7, 13 and 14 revealed a significant broad spectrum of antitumor potential against most of the tested subpanel tumor cell lines at the GI50 and TGI levels, together with a mild cytotoxic (LC50) activity. Compounds 13 and 14 proved to be the most active antitumor members identified in this study.