Synthesis 2008(2): 225-228  
DOI: 10.1055/s-2007-1000855
PAPER
© Georg Thieme Verlag Stuttgart · New York

A Convenient Synthesis of 1-(4-Fluorophenyl)-2-(4-pyridyl)cyclopentene from Cyclopentanone

Bassam Abu Thahera, Pierre Kochb, Vicente Del Amoc, Paul Knochelc, Stefan Laufer*b
a Faculty of Science, Chemistry Department, Islamic University of Gaza, Gaza Strip, Palestine
b Institute of Pharmacy, Department of Pharmaceutical and Medicinal Chemistry, Eberhard-Karls-University Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany
Fax: +49(7071)295037; e-Mail: stefan.laufer@uni-tuebingen.de;
c Institute of Chemistry and Biochemistry, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
Further Information

Publication History

Received 31 July 2007
Publication Date:
18 December 2007 (online)

Abstract

In the framework of investigating the role of pyridyl-substituted five-membered heterocycles as potential p38 mitogen-activated protein kinase inhibitors, we synthesized the disubstituted carbocyclic analogue, 1-(4-fluorophenyl)-2-(4-pyridyl)cyclopentene. A multistep synthesis of this compound starting from cyclopentanone is reported. Cyclopentanone was converted into 1-cy-­clo­pentenyl-4-fluorobenzene using a Grignard reaction. The oxidation of this product with hydrogen peroxide and formic acid gave 2-(4-fluorophenyl)cyclopentanone. This ketone was activated using a neodymium salt (NdCl3·2LiCl) and subsequently reacted with a complexed Grignard reagent (pyMgCl·LiCl) to give the corresponding cyclopentanol derivative. Finally, dehydration of the latter alcohol led to the title compound.