A series of 2 amimo 3 cyano 7,7 dimethyl 4 aryl 5 oxo 5,6,7,8 tetra 4H chromenes were synthesized in the absence of catalyst. Their structures were determined by IR, 1H NMR, and single crystal X ray diffraction.
In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4...In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.展开更多
3,4Dehydro3hydroxy4phenylpyran2,5dione is an important intermediate of benzoquinones which have the ability to reduce plasma level of glucose.We selected a novel method to prepare the intermediate from...3,4Dehydro3hydroxy4phenylpyran2,5dione is an important intermediate of benzoquinones which have the ability to reduce plasma level of glucose.We selected a novel method to prepare the intermediate from phenylacetyl chloride in this paper.The facile synthetic scheme put forward in this paper is simple to operate and has the characteristic of high yield and good feasibility.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A series of 2 amimo 3 cyano 7,7 dimethyl 4 aryl 5 oxo 5,6,7,8 tetra 4H chromenes were synthesized in the absence of catalyst. Their structures were determined by IR, 1H NMR, and single crystal X ray diffraction.
文摘In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.
文摘3,4Dehydro3hydroxy4phenylpyran2,5dione is an important intermediate of benzoquinones which have the ability to reduce plasma level of glucose.We selected a novel method to prepare the intermediate from phenylacetyl chloride in this paper.The facile synthetic scheme put forward in this paper is simple to operate and has the characteristic of high yield and good feasibility.
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.
