Mohammad Bakherad - School of Chemistry, Shahrood University of Technology, Shahrood ۳۶۱۹۹۹۵۱۶۱, Iran
Elmira Moradian - School of Chemistry, Shahrood University of Technology, Shahrood ۳۶۱۹۹۹۵۱۶۱, Iran

Tetrahydrobenzo[b]pyran derivatives were synthesized in the presence of silicapropyl-caffeine hydrogen sulfate ([Sipcaf]HSO4) as a recyclable solid acid catalyst from the reaction between aldehydes, malononitrile, and 1,3-cyclohexanedione or 5,5- dimethyl-1,3-cyclohexanedione at 100 ºC under solvent-free conditions.

Tetrahydrobenzo[b]pyran, silicapropyl-caffeine hydrogen sulfate ([Sipcaf] HSO4), Solvent-free