ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Tungstate sulfuric acid: preparation, characterization, and application in catalytic synthesis of novel benzimidazoles

Bahador Karami, Saeed Khodabakhshi, and Zahra Haghighijou

Department of Chemistry, Yasouj University, 75918-74831 Yasouj, P.O. Box 353, Iran

E-mail: karami@mail.yu.ac.ir

Abstract: Tungstate sulfuric acid (TSA) was prepared, characterized, and applied for direct synthesis of novel and known benzimidazoles through a condensation reaction of o-phenylenediamines with orthoesters under solvent-free conditions. TSA was characterized by powdered X-ray diffraction (XRD), X-ray fluorescence (XRF), and FTIR spectroscopy. This novel and eco-friendly method is very cheap and has many advantages such as excellent yields, recyclable and eco-friendly catalyst, and simple work-up procedure.

Keywords: orthoesters – o-phenylenediamine – tungstate sulfuric acid – benzimidazole – catalyst

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-012-0152-4

Chemical Papers 66 (7) 684–690 (2012)