1. a Laboratory of Molecular Design and Synthesis, Department of Chemistry , Katholieke Universiteit Leuven , Celestijnenlaan 200F, B-3001 , Leuven , Belgium
2. b Laboratory of Applied Organic Chemistry, Chemistry of Heterocycles Group, Department of Chemistry , Badji Mokhtar University of Annaba , PO Box 12, Annaba , 23000 , Algeria