PAPER	Synthesis 2004: 1015-1020   DOI: 10.1055/s-2004-822343
© Georg Thieme Verlag Stuttgart · New York
Activated Carbon-Promoted Oxidative Aromatization of Hantzsch 1,4-Dihydropyridines and 1,3,5-Trisubstituted Pyrazolines Using Molecular Oxygen
Natsuki Nakamichi, Yuka Kawashita, Masahiko Hayashi*
Department of Chemistry, Faculty of Science, Kobe University, Kobe 657-8501, Japan Fax: +81(78)8035688; e-Mail: mhayashi@kobe-u.ac.jp;
Received 8 December 2003

Abstract

In the presence of activated carbon, Hantzsch 1,4-dihydropyridines and 1,3,5-trisubstituted pyrazolines were aromatized with molecular oxygen to the corresponding pyridines and pyrazoles in excellent yields.

Key words

activated carbon - aromatization - oxidations - pyridines - pyrazolines - heterocycles