Synthesis of ferrocenyl substituted pyrazoles as potential antitumor substances

ORGN 138

Metin Zora,, Günseli Turgut2, and Meral Görmen1. (1) Department of Chemistry, Middle East Technical University, Ankara, 06531, Turkey, (2) Department of Chemistry, Akdeniz University, Antalya, 07058, Turkey
Pyrazoles have a wide spectrum of biological activity including antitumor and anticancer activities. Ferrocene is often incorporated into a molecule of an organic compound in order to obtain enhanced biological activity since some ferrocene derivatives have already proved to be active against a number of tumors. Incorporation of the essential structures of pyrazoles with a ferrocene moiety could provide compounds with enhanced antitumor activities. We have investigated the synthesis of 1-alkyl/aryl-5-ferrocenyl-1H-pyrazoles (3) and 1-alkyl/aryl-3-ferrocenyl-1H-pyrazoles (4). When treated with hydrazines, (2-formylethynyl)ferrocene (1) or (2-formyl-1-chlorovinyl)ferrocene (2) produces 1,5- and/or 1,3-pyrazole isomers 3 and 4. In most cases, 1,5-pyrazole isomers 3 are obtained as major products. The scope, limitations and mechanism of the reactions will be discussed.