dihydropyrimidinones derivatives were synthesized in high yields by one pot three component Biginelli condensation from aldehyde, β keto ester and urea in ethanol,while cobalt chloride hexahydrate was used as a catal...dihydropyrimidinones derivatives were synthesized in high yields by one pot three component Biginelli condensation from aldehyde, β keto ester and urea in ethanol,while cobalt chloride hexahydrate was used as a catalyst.This modified Biginellis reaction not only makes the reaction period short,the operation simple,but also gives high yields.展开更多
A novel catalyst indium(Ⅲ) tribromide is shown to efficiently promote 5-carbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones from a three-component coupling of β-diketones, aldehydes and urea in ethanol. This modified on...A novel catalyst indium(Ⅲ) tribromide is shown to efficiently promote 5-carbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones from a three-component coupling of β-diketones, aldehydes and urea in ethanol. This modified one-pot Biginelli′s cyclocondensation not only features simple operation, but also takes place in nonpolluted environment. The structure of the Biginelli reaction product from β-diketones, salicylaldehyde and urea has been proposed to possess an oxygen-bridge.展开更多
3,4-Dihydropyrimidin-2-(1H)-ones were synthesized in high yields by a one-pot cyclocondensation of aldehyde,1,3-dicarbonyl compound,and urea or thiourea using copper o-toluenesulfonate as a catalyst under solvent-free...3,4-Dihydropyrimidin-2-(1H)-ones were synthesized in high yields by a one-pot cyclocondensation of aldehyde,1,3-dicarbonyl compound,and urea or thiourea using copper o-toluenesulfonate as a catalyst under solvent-free conditions at 90℃.Effects of molar ratio of reactants,amount of catalyst,and reaction temperature on the yields of 3,4-dihydropyrimidin-2-(1H)-ones were investigated.The results showed that at the condition of naldehyde∶n1,3-dicarbonyl compounds∶nurea(or thiourea)=1∶1.2∶1.5,1 mol% catalyst(molar percent of aldehyde),2.0 h at 90℃,the yields of products were 51-96%.After reaction,the catalyst could be reused for four times without distinct loss of catalytic activity.展开更多
文摘dihydropyrimidinones derivatives were synthesized in high yields by one pot three component Biginelli condensation from aldehyde, β keto ester and urea in ethanol,while cobalt chloride hexahydrate was used as a catalyst.This modified Biginellis reaction not only makes the reaction period short,the operation simple,but also gives high yields.
文摘A novel catalyst indium(Ⅲ) tribromide is shown to efficiently promote 5-carbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones from a three-component coupling of β-diketones, aldehydes and urea in ethanol. This modified one-pot Biginelli′s cyclocondensation not only features simple operation, but also takes place in nonpolluted environment. The structure of the Biginelli reaction product from β-diketones, salicylaldehyde and urea has been proposed to possess an oxygen-bridge.
文摘3,4-Dihydropyrimidin-2-(1H)-ones were synthesized in high yields by a one-pot cyclocondensation of aldehyde,1,3-dicarbonyl compound,and urea or thiourea using copper o-toluenesulfonate as a catalyst under solvent-free conditions at 90℃.Effects of molar ratio of reactants,amount of catalyst,and reaction temperature on the yields of 3,4-dihydropyrimidin-2-(1H)-ones were investigated.The results showed that at the condition of naldehyde∶n1,3-dicarbonyl compounds∶nurea(or thiourea)=1∶1.2∶1.5,1 mol% catalyst(molar percent of aldehyde),2.0 h at 90℃,the yields of products were 51-96%.After reaction,the catalyst could be reused for four times without distinct loss of catalytic activity.
