Synthesis of ferrocenyl substituted pyrazoles as potential antitumor substances

ORGN 138

Metin Zora, zora@metu.edu.tr1, 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.