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

One-pot synthesis of 2-amino-3-cyano-4-arylsubstituted tetrahydrobenzo[b]pyrans catalysed by silica gel-supported polyphosphoric acid (PPA-SiO₂) as an efficient and reusable catalyst

Abolghasem Davoodnia, Sadegh Allameh, Samineh Fazli, and Niloofar Tavakoli-Hoseini

Department of Chemistry, Mashhad Branch, Islamic Azad University, 91735-413 Mashhad, Iran

E-mail: adavoodnia@mshdiau.ac.ir

Abstract: A convenient method for the synthesis of tetrahydrobenzo[b]pyrans by a one-pot three-component cyclocondensation of dimedone, aryl aldehydes, and malononitrile in water using silica gel-supported polyphosphoric acid (PPA-SiO₂) as an efficient and reusable catalyst is described. The present methodology offers several advantages, such as a simple procedure with ease of handling, short reaction time, high yields, and the absence of any volatile and hazardous organic solvents.

Keywords: tetrahydrobenzo[b]pyrans – PPA-SiO2 – heterogeneous catalysis – aqueous media

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-011-0064-8

Chemical Papers 65 (5) 714–720 (2011)