K. Niknam, Abbas Jamali
Nov 1, 2012
Citations
1
Influential Citations
66
Citations
Journal
Chinese Journal of Catalysis
Abstract
A simple and efficient procedure for the preparation of silica-bonded N-propylpiperazine sodium n-propionate (SBPPSP) by the hydrolysis of silica-bonded N-propylpiperazine methyl n-propionate (SBPPMP) in hydrochloric acid (0.5 mol/L) followed by treatment with saturated sodium bicarbonate is described. The SBPPMP was obtained by the reaction of 3-silica-bonded N-propylpiperazine and methyl acrylate in methanol. SBPPSP was used as a recyclable basic catalyst for the synthesis of 3,4-dihydropyrano[c]chromenes by the reaction of aromatic aldehydes, malononitrile, and 4-hydroxycoumarin in aqueous ethanol (1:1 v/v) under reflux conditions. Biscoumarins were also obtained via condensation of aldehydes and 4-hydroxycoumarin in aqueous ethanol (1:1 v/v) under reflux conditions. The catalyst could be recycled several times without any additional treatment.