Oxidative cyclocondensation of o-aminobenzamide with various aldehydes in water using I2/KI as catalyst and oxidizing agent is carded out giving the corresponding quinazolin-4（3H）-ones 3a-n in good to excellent yields.
A self-intermolecular cyclocondensation reaction of 3,4-dihydropyrimidine-2-thione（DHPM） to give a novel tricyclic structure containing DHPM core in the presence of diethyl azodicarboxylate（DEAD） and triphenylphos...A self-intermolecular cyclocondensation reaction of 3,4-dihydropyrimidine-2-thione（DHPM） to give a novel tricyclic structure containing DHPM core in the presence of diethyl azodicarboxylate（DEAD） and triphenylphosphine（TPP） at room temperature is reported.展开更多
We discovered that a-chymotrypsin has a promiscuous ability to catalyze the cyclocondensation of aromatic and aliphatic aldehydes with 2-aminobenzamides to afford the corresponding 2,3-dihydroquinazolin-4（1H）-ones s...We discovered that a-chymotrypsin has a promiscuous ability to catalyze the cyclocondensation of aromatic and aliphatic aldehydes with 2-aminobenzamides to afford the corresponding 2,3-dihydroquinazolin-4（1H）-ones successfully in high yields（90%–98%） under alcohol solvent. The catalytic activity of a-chymotrypsin was evaluated through investigating the temperature, the enzyme loading and the ratio of substrates in the enzyme-catalyzed reactions. The present method proves to be efficient and environmentally friendly in terms of short reaction time, high yield, green catalyst and the clean products obtained without further purification processes.展开更多
Mesoporous MCM-41 supported Schiff base and Cu SO4· 5H2 O shows high catalytic activity in the cyclocondensation of mercaptoacetic acid with imines（or aldehydes and amines） to afford pharmaceutically important ...Mesoporous MCM-41 supported Schiff base and Cu SO4· 5H2 O shows high catalytic activity in the cyclocondensation of mercaptoacetic acid with imines（or aldehydes and amines） to afford pharmaceutically important thiazolidinone derivatives. The catalytic reactions involving twocomponents or three-components afforded the desired product in high yields（up to 98% and 99%）.Moreover, the catalyst works well with respect to recyclability, giving the product in 85% and 83% yields after recycling six times.展开更多
4H-Benzo[b]pyrans was synthesized under reflux condition in ethanol via condensation of benzaldehyde, malononitrile and dimedone with ZnO-beta zeolite as an inexpensive and effective catalyst. The key features of the ...4H-Benzo[b]pyrans was synthesized under reflux condition in ethanol via condensation of benzaldehyde, malononitrile and dimedone with ZnO-beta zeolite as an inexpensive and effective catalyst. The key features of the reported protocols are good to excellent yields, short reaction time and recovery and reusability of catalytic material.展开更多
l-Methyl-3-ethyl imidazolium bromide[meim]Br/basic alumina（Al2O3） has been found to promote the cyclocondensation of chloroacetone/chloroethyl acetate with salicylaldehydes under conventional as well as microwave ir...l-Methyl-3-ethyl imidazolium bromide[meim]Br/basic alumina（Al2O3） has been found to promote the cyclocondensation of chloroacetone/chloroethyl acetate with salicylaldehydes under conventional as well as microwave irradiation to yield benzofuran derivatives.展开更多
A convenient solvent less cyclocondensation from thiosemicarbazone of benzofuranone and chloroacetic acid using an ionic liquid, N-methylpyridinium tosylate for obtaining novel 4-thiazolidinones in excellent yields is...A convenient solvent less cyclocondensation from thiosemicarbazone of benzofuranone and chloroacetic acid using an ionic liquid, N-methylpyridinium tosylate for obtaining novel 4-thiazolidinones in excellent yields is reported. Also, the green expedient synthesis of new 2,4-disubstituted thiazoles under grinding condition from phenacyl bromides and thiosemicarbazide derivatives in quantitative yields is reported.展开更多
A facile and inexpensive method for the synthesis of 2-substituted benzothiazoles has been developed by Na2S2O4-mediated cyclocondensations of 2,2＇-disulfanediyldianilines with aldehydes. In the presence of Na2S2O4 a...A facile and inexpensive method for the synthesis of 2-substituted benzothiazoles has been developed by Na2S2O4-mediated cyclocondensations of 2,2＇-disulfanediyldianilines with aldehydes. In the presence of Na2S2O4 and 4 ,A molecular sieves, a variety of 2-substituted benzotbiazoles were obtained from the reaction of 2,2＇-disulfanediyldianilines with aldehydes in moderate to high yields.展开更多
A convenient synthesis of 6-amino-2H,4H-pyrano[2,3-F]pyrazole-5-carbonitriles has been accomplished by one pot four-component cyclocondensation of aromatic aldehydes（1a-o） malanonitrile（2）, ethyl acetoacetate（3）...A convenient synthesis of 6-amino-2H,4H-pyrano[2,3-F]pyrazole-5-carbonitriles has been accomplished by one pot four-component cyclocondensation of aromatic aldehydes（1a-o） malanonitrile（2）, ethyl acetoacetate（3）, and hydrazine hydrate（4） in freshly prepared deep eutectic solvent, DES（choline chloride：urea）. This protocol has afforded corresponding pyrano[2,3-F]pyrazoles in shorter reaction time with high yields, and it avoids the use of typical toxic catalysts and solvents.展开更多
A facile one-pot synthesis of new 3-arylthieno[2,3-d]pyrimidine-2,4（1H,3H）-diones via base-catalyzed cyclocondensation of ethyl 2-amino-4,5-dimethylthiophene-3-carboxylate with aryl isocyanates is described.
Microwave irradiation was used to accelerate the cyclocondensation of i soflavones and 5-amino-1H-imidazole- 4-carboxamide in the presence of sodium hydroxide to produce 3,4-diphenyl-imidazo[ 1,5-a]pyrimidines in good...Microwave irradiation was used to accelerate the cyclocondensation of i soflavones and 5-amino-1H-imidazole- 4-carboxamide in the presence of sodium hydroxide to produce 3,4-diphenyl-imidazo[ 1,5-a]pyrimidines in good to moderate yields.展开更多
文摘Oxidative cyclocondensation of o-aminobenzamide with various aldehydes in water using I2/KI as catalyst and oxidizing agent is carded out giving the corresponding quinazolin-4（3H）-ones 3a-n in good to excellent yields.
基金financial support from the National Nature Science Foundation of China(No.20902073)the Natural Science Foundation of Gansu Province(No.096RJZA116)Scientific and Technological Innovation Engineering program of Northwest Normal University(nwnu-kjcxgc-03-64)
文摘A self-intermolecular cyclocondensation reaction of 3,4-dihydropyrimidine-2-thione（DHPM） to give a novel tricyclic structure containing DHPM core in the presence of diethyl azodicarboxylate（DEAD） and triphenylphosphine（TPP） at room temperature is reported.
基金the financial support of the National Natural Science Foundation of China (Nos. 21262002, 21462001 and 21465002)the Program for Changjiang Scholars and Innovative Research Team in University (IRT13054)+1 种基金the Natural Science Foundation of Jiangxi No. 20142BAB203008)the Science and Technology Foundation of the Jiangxi Education Department (Nos. KJLD12006, GJJ14466 and KJLD14050)
文摘We discovered that a-chymotrypsin has a promiscuous ability to catalyze the cyclocondensation of aromatic and aliphatic aldehydes with 2-aminobenzamides to afford the corresponding 2,3-dihydroquinazolin-4（1H）-ones successfully in high yields（90%–98%） under alcohol solvent. The catalytic activity of a-chymotrypsin was evaluated through investigating the temperature, the enzyme loading and the ratio of substrates in the enzyme-catalyzed reactions. The present method proves to be efficient and environmentally friendly in terms of short reaction time, high yield, green catalyst and the clean products obtained without further purification processes.
基金the National Natural Science Foundation of China(Nos.21162026,21262034 and 21362036)Doctoral Fund of Xinjiang University(No.BS110111)for financial support,Xinjiang University Analytical&Testing Center for instrumental analyses,and Adamas-beta Chemical Co.,for all chemical reagents
文摘Mesoporous MCM-41 supported Schiff base and Cu SO4· 5H2 O shows high catalytic activity in the cyclocondensation of mercaptoacetic acid with imines（or aldehydes and amines） to afford pharmaceutically important thiazolidinone derivatives. The catalytic reactions involving twocomponents or three-components afforded the desired product in high yields（up to 98% and 99%）.Moreover, the catalyst works well with respect to recyclability, giving the product in 85% and 83% yields after recycling six times.
文摘4H-Benzo[b]pyrans was synthesized under reflux condition in ethanol via condensation of benzaldehyde, malononitrile and dimedone with ZnO-beta zeolite as an inexpensive and effective catalyst. The key features of the reported protocols are good to excellent yields, short reaction time and recovery and reusability of catalytic material.
文摘l-Methyl-3-ethyl imidazolium bromide[meim]Br/basic alumina（Al2O3） has been found to promote the cyclocondensation of chloroacetone/chloroethyl acetate with salicylaldehydes under conventional as well as microwave irradiation to yield benzofuran derivatives.
文摘A convenient solvent less cyclocondensation from thiosemicarbazone of benzofuranone and chloroacetic acid using an ionic liquid, N-methylpyridinium tosylate for obtaining novel 4-thiazolidinones in excellent yields is reported. Also, the green expedient synthesis of new 2,4-disubstituted thiazoles under grinding condition from phenacyl bromides and thiosemicarbazide derivatives in quantitative yields is reported.
基金Project supported by the National Natural Science Foundation of China （No. 20872112）, Zhejiang Provincial Natural Science Foundation of China （Nos. Y407116 and Y4080169）, and the Natural Science Foundation of Wenzhou University （No. 2007L004）.
文摘A facile and inexpensive method for the synthesis of 2-substituted benzothiazoles has been developed by Na2S2O4-mediated cyclocondensations of 2,2＇-disulfanediyldianilines with aldehydes. In the presence of Na2S2O4 and 4 ,A molecular sieves, a variety of 2-substituted benzotbiazoles were obtained from the reaction of 2,2＇-disulfanediyldianilines with aldehydes in moderate to high yields.
文摘A convenient synthesis of 6-amino-2H,4H-pyrano[2,3-F]pyrazole-5-carbonitriles has been accomplished by one pot four-component cyclocondensation of aromatic aldehydes（1a-o） malanonitrile（2）, ethyl acetoacetate（3）, and hydrazine hydrate（4） in freshly prepared deep eutectic solvent, DES（choline chloride：urea）. This protocol has afforded corresponding pyrano[2,3-F]pyrazoles in shorter reaction time with high yields, and it avoids the use of typical toxic catalysts and solvents.
文摘A facile one-pot synthesis of new 3-arylthieno[2,3-d]pyrimidine-2,4（1H,3H）-diones via base-catalyzed cyclocondensation of ethyl 2-amino-4,5-dimethylthiophene-3-carboxylate with aryl isocyanates is described.
文摘Microwave irradiation was used to accelerate the cyclocondensation of i soflavones and 5-amino-1H-imidazole- 4-carboxamide in the presence of sodium hydroxide to produce 3,4-diphenyl-imidazo[ 1,5-a]pyrimidines in good to moderate yields.
