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 ac...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.展开更多
Poly(4-vinylpyridinium) perchlorate has been used as an efficient solid acid catalyst for the synthesis of 3,3'-(arylmethylene)bis(4-hydroxycoumarins) and bis(indolyl)methanes, with the products being formed in ex...Poly(4-vinylpyridinium) perchlorate has been used as an efficient solid acid catalyst for the synthesis of 3,3'-(arylmethylene)bis(4-hydroxycoumarins) and bis(indolyl)methanes, with the products being formed in excellent yields over very short reaction times under mild and environmentally friendly conditions. This catalyst can be reused several times without any appreciable loss in its activity.展开更多
α, α＇-Benzylidene bis（4-hydroxycoumarin） derivatives were readily prepared in a few minutes with good yields through the reaction of an aromatic aldehyde and 4-hydroxycoumarin in aqueous media in the presence of ...α, α＇-Benzylidene bis（4-hydroxycoumarin） derivatives were readily prepared in a few minutes with good yields through the reaction of an aromatic aldehyde and 4-hydroxycoumarin in aqueous media in the presence of catalytic tris（hydrogensulfato） boron [B（HSO_4）_3].展开更多
A simple, efficient, and ecofriendly procedure has been developed using propane-l,2,3-triyl tris（hydrogen sulfate） as a catalyst for the synthesis of biscoumarin derivatives in water and solvent-free conditions. The...A simple, efficient, and ecofriendly procedure has been developed using propane-l,2,3-triyl tris（hydrogen sulfate） as a catalyst for the synthesis of biscoumarin derivatives in water and solvent-free conditions. The significant features of the present protocol are simplicity, environmentally benign, high yields, no chromatographic separation, and recyclability of the catalyst.展开更多
基金Persian Gulf University Research Council for partial support of this work, PGU/FS/6-2/1390/694
文摘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.
基金the University of Guilan Research Council for the partial support of this work
文摘Poly(4-vinylpyridinium) perchlorate has been used as an efficient solid acid catalyst for the synthesis of 3,3'-(arylmethylene)bis(4-hydroxycoumarins) and bis(indolyl)methanes, with the products being formed in excellent yields over very short reaction times under mild and environmentally friendly conditions. This catalyst can be reused several times without any appreciable loss in its activity.
文摘α, α＇-Benzylidene bis（4-hydroxycoumarin） derivatives were readily prepared in a few minutes with good yields through the reaction of an aromatic aldehyde and 4-hydroxycoumarin in aqueous media in the presence of catalytic tris（hydrogensulfato） boron [B（HSO_4）_3].
基金Firoozabad University Research Council for the partialfinancial support
文摘A simple, efficient, and ecofriendly procedure has been developed using propane-l,2,3-triyl tris（hydrogen sulfate） as a catalyst for the synthesis of biscoumarin derivatives in water and solvent-free conditions. The significant features of the present protocol are simplicity, environmentally benign, high yields, no chromatographic separation, and recyclability of the catalyst.
