Current location: JICS Archive > Vol. 5 > Supplement. 1 > Articles : 8

Silica Sulfuric Acid Catalyzed Synthesis of Benzoxazoles, Benzimidazoles and Oxazolo[4,5-b]pyridines Under Heterogeneous and Solvent-Free Conditions

I. Mohammadpoor-Baltork^a,* , M. Moghadam^a, S. Tangestaninejad^a, V. Mirkhani^b, M.A. Zolfigol and S.F. Hojati^a

^a Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan, Iran
^b Faculty of Chemistry, Bu-Ali Sina University, Hamadan, Iran

A simple, rapid and efficient method for the preparation of benzoxazoles, benzimidazoles and oxazolo[4,5-b]pyridines from the reaction of orthoesters with o-aminophenols, o-phenylenediamine and 2-amino-3-hydroxypyridine in the presence of silica sulfuric acid under heterogeneous and solvent-free conditions is reported. The significant features of this method are short reaction times, high yields of the products, mild reaction conditions, solvent free reaction, cheapness, non-toxicity and reusability of the catalyst.

Keywords: Benzoxazole, Benzimidazole, Oxazolo[4,5-b]pyridine, Orthoester, Silica sulfuric acid, Solvent-free.