Formylchrone reacted with aroylhydrazine to give corresponding hydrazone, which was treated with acetic anhydride to give a series of chromones with substitution of 1,3,4 dihydrooxadiazoly in 3 position. The chromone ...Formylchrone reacted with aroylhydrazine to give corresponding hydrazone, which was treated with acetic anhydride to give a series of chromones with substitution of 1,3,4 dihydrooxadiazoly in 3 position. The chromone formation reaction could be finished in a much short time by microwave irradiation heating.展开更多
Eight 5-substituted-1,3,4-oxadiazole-2-ones were synthesized using substituted benzoic hydrazides as starting materials and triphosgene as cyclization reagent at ambient temperature with high purity and good yields.Th...Eight 5-substituted-1,3,4-oxadiazole-2-ones were synthesized using substituted benzoic hydrazides as starting materials and triphosgene as cyclization reagent at ambient temperature with high purity and good yields.Their structures were characterized by IR,MS,1H NMR and elemental analysis.The salient features of this method included the simple reaction set-ups,safety,short reaction time and high yields of products.展开更多
Dihydroquinazolin-4(3H)-ones were synthesized by the reaction of o-nitrobenzamides with aromatic aldehydes or cyclones promoted by the low-valent titanium reagent(TiCl 4-Zn system). The products were characterized by ...Dihydroquinazolin-4(3H)-ones were synthesized by the reaction of o-nitrobenzamides with aromatic aldehydes or cyclones promoted by the low-valent titanium reagent(TiCl 4-Zn system). The products were characterized by elementary analysis, IR, 1H NMR and X-ray single crystal diffraction. This method possesses the advantages of easily accessible starting materials, convenient manipulation and moderate to high yields.展开更多
Isoxazole derivatives were characterized by broad spectrum of biological activities, but the condensed heterocyclic compounds containing isoxazole were scarcely reported. In this paper, we studied the 1,3-dipolar cycl...Isoxazole derivatives were characterized by broad spectrum of biological activities, but the condensed heterocyclic compounds containing isoxazole were scarcely reported. In this paper, we studied the 1,3-dipolar cycloaddition of p-methoxybenzohydroxamoyl chloride with ethyl sodioacetoacetate to obtain a key intermediate 2. Through compound 2, fifteen novel S-triazolo-1,3,4-thiadiazines(5a-5e), imidazolo-1,3,4-thiadiazoles(9a-9e) and imidazolo-1,3,4-oxadiazoles(10a-10e) containing isoxazole, which have potentially useful biological activities, were synthesized. The structures of the products were confirmed by elemental analyses and spectral analysis. And the characteristic data of IR, 1H NMR and MS were explained reasonably.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Formylchrone reacted with aroylhydrazine to give corresponding hydrazone, which was treated with acetic anhydride to give a series of chromones with substitution of 1,3,4 dihydrooxadiazoly in 3 position. The chromone formation reaction could be finished in a much short time by microwave irradiation heating.
文摘Eight 5-substituted-1,3,4-oxadiazole-2-ones were synthesized using substituted benzoic hydrazides as starting materials and triphosgene as cyclization reagent at ambient temperature with high purity and good yields.Their structures were characterized by IR,MS,1H NMR and elemental analysis.The salient features of this method included the simple reaction set-ups,safety,short reaction time and high yields of products.
文摘Dihydroquinazolin-4(3H)-ones were synthesized by the reaction of o-nitrobenzamides with aromatic aldehydes or cyclones promoted by the low-valent titanium reagent(TiCl 4-Zn system). The products were characterized by elementary analysis, IR, 1H NMR and X-ray single crystal diffraction. This method possesses the advantages of easily accessible starting materials, convenient manipulation and moderate to high yields.
文摘Isoxazole derivatives were characterized by broad spectrum of biological activities, but the condensed heterocyclic compounds containing isoxazole were scarcely reported. In this paper, we studied the 1,3-dipolar cycloaddition of p-methoxybenzohydroxamoyl chloride with ethyl sodioacetoacetate to obtain a key intermediate 2. Through compound 2, fifteen novel S-triazolo-1,3,4-thiadiazines(5a-5e), imidazolo-1,3,4-thiadiazoles(9a-9e) and imidazolo-1,3,4-oxadiazoles(10a-10e) containing isoxazole, which have potentially useful biological activities, were synthesized. The structures of the products were confirmed by elemental analyses and spectral analysis. And the characteristic data of IR, 1H NMR and MS were explained reasonably.
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.
