A general and convenient practical approach for the synthesis of polyhydroquinoline derivatives has been achieved via one-pot four-component Hantzsch condensation of aromatic aldehydes, dimedone, ethyl acetoacetate an...A general and convenient practical approach for the synthesis of polyhydroquinoline derivatives has been achieved via one-pot four-component Hantzsch condensation of aromatic aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in the presence of a catalytic amount of cerium(IV) ammonium nitrate (CAN), in ethanol solvent at ambient temperature. Simple work-up, mild reaction conditions, inexpensive and non-toxic catalyst, and excellent product yields are the advantageous features of this method.展开更多
The modification of high-performance liquid chromatography parameters leads to a more effective oligonucleotide-A purification process. Using various experimental parameters such as buffer, concentration, and pH, a me...The modification of high-performance liquid chromatography parameters leads to a more effective oligonucleotide-A purification process. Using various experimental parameters such as buffer, concentration, and pH, a method for optimizing the purification of an oligonucleotide-A on a reverse-phase C18 column was created. To purify oligonucleotide-A, High-Performance Liquid Chromatography (HPLC), Ultraviolet-Visible Spectrophotometry (UV-Vis), Liquid Chromatography-Mass Spectrometry (LC-MS), and lyophilization were used. Chromatographic data were collected with a semi-prep HPLC system, quantified with the UV-Vis technique, and validated with the LC-MS method. The most optimized parameters found to obtain the purity of 93.0% are 40 mM triethylammonium bicarbonate (TEAB) buffer with pH 7, which is approximately 6.0% higher than the reported method of which the purity is 87.0%. However, the yield under these conditions was reduced by about 5%. The worst possible optimized settings that resulted in the lowest purity (84.0%) and yield (69.0%) are 10 mM ammonium acetate (NH<sub>4</sub>CH<sub>3</sub>CO<sub>2</sub>) with pH 7.展开更多
An efficient one-pot synthesis of 2,4,6-triarylpyridines has been described.This involves the three-component reaction of aldehydes,ketones and ammonium acetate in the presence of a catalytic amount of wet 2,4,6-trich...An efficient one-pot synthesis of 2,4,6-triarylpyridines has been described.This involves the three-component reaction of aldehydes,ketones and ammonium acetate in the presence of a catalytic amount of wet 2,4,6-trichloro-1,3,5-triazine(TCT) under solvent-free condition at 130℃.展开更多
A series of 1,4-dihydropyridines have been prepared by a one-pot condensation of aldehydes,ethyl acetoacetate,and ammonium acetate in the presence of a heterogeneous catalyst silica sulfuric acid at room temperature u...A series of 1,4-dihydropyridines have been prepared by a one-pot condensation of aldehydes,ethyl acetoacetate,and ammonium acetate in the presence of a heterogeneous catalyst silica sulfuric acid at room temperature under solvent-free condition. This new protocol has the advantage of short reaction time and excellent yields,and is an environmentally benign route to the synthesis of 1,4-dihydropyridines.展开更多
A simple and efficient method has been developed;benzil/benzoin undergoes smooth condensation with various substituted aldehyde and ammonium acetate in the presence of potassium dihydrogen phosphate(KH;PO;) under mi...A simple and efficient method has been developed;benzil/benzoin undergoes smooth condensation with various substituted aldehyde and ammonium acetate in the presence of potassium dihydrogen phosphate(KH;PO;) under mild reaction conditions to afford the corresponding trisubstituted imidazole in excellent yields.The method for synthesis of product,the reaction mixture was reflux in ethanol for 40-90 min.The present method is simple,efficient,and cost-effective.展开更多
A simple one-pot synthetic method for the preparation of 2,4,5-triaryl-lH-imidazoles from benzoin or benzil, ammonium acetate, aromatic aldehydes, and ZrOCl2-8H2O catalyst is described. The ZrOCl2-8H2O catalyst was fo...A simple one-pot synthetic method for the preparation of 2,4,5-triaryl-lH-imidazoles from benzoin or benzil, ammonium acetate, aromatic aldehydes, and ZrOCl2-8H2O catalyst is described. The ZrOCl2-8H2O catalyst was found to be equally effective for aromatic and heteroaromatic aldehydes and also for the preparation of substituted 1,4-di(4,5-diphenylimidazol-yl) benzene.展开更多
Twenty 2,3-disubstituted-4(3H)-quinazolinones were synthesed by one-pot three-component method with isa- toic anhydride, orthoesters and amines as raw materials in the presence of KAI(SO4)2·12H2O (Alum) und...Twenty 2,3-disubstituted-4(3H)-quinazolinones were synthesed by one-pot three-component method with isa- toic anhydride, orthoesters and amines as raw materials in the presence of KAI(SO4)2·12H2O (Alum) under micro- wave irradiation and solvent-free conditions. 6-Bromo-2-propyl-3-p-tolylquinazolin-4(3H)-one (4m), 6-bromo-2- methyl-3-phenethylquinazolin-4(3H)-one (4n) and 6-bromo-2-ethyl-3-phenethylquinazolin-4(3H)-one (40) were characterized by IR, 1H NMR, 13C NMR and elemental analysis.展开更多
A facile synthesis of benzofuro[2,3-c]pyridines has been achieved under mild conditions by using ammonium acetate as the nitrogen source through intramolecular cascade annulation.This reaction could efficiently constr...A facile synthesis of benzofuro[2,3-c]pyridines has been achieved under mild conditions by using ammonium acetate as the nitrogen source through intramolecular cascade annulation.This reaction could efficiently construct pyridine ring and furan ring in one step.Moreover,the key annulation step was demonstrated through dihydrobenzofuran intermediates.展开更多
Various 2-phenylimidazo [4,5-f] [1,10] phenanthrolines were synthesized from potassium ferro-cyanide trihydrate (KFCT) complex catalyzed three component reaction of 1,10-phenanthroline-5,6-dione, aromatic aldehydes ...Various 2-phenylimidazo [4,5-f] [1,10] phenanthrolines were synthesized from potassium ferro-cyanide trihydrate (KFCT) complex catalyzed three component reaction of 1,10-phenanthroline-5,6-dione, aromatic aldehydes and ammonium acetate at room temperature in excellent isolated yield. This is a simple and straight forward, high yielding, not involving any hazardous or expensive catalyst method.展开更多
文摘A general and convenient practical approach for the synthesis of polyhydroquinoline derivatives has been achieved via one-pot four-component Hantzsch condensation of aromatic aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in the presence of a catalytic amount of cerium(IV) ammonium nitrate (CAN), in ethanol solvent at ambient temperature. Simple work-up, mild reaction conditions, inexpensive and non-toxic catalyst, and excellent product yields are the advantageous features of this method.
文摘The modification of high-performance liquid chromatography parameters leads to a more effective oligonucleotide-A purification process. Using various experimental parameters such as buffer, concentration, and pH, a method for optimizing the purification of an oligonucleotide-A on a reverse-phase C18 column was created. To purify oligonucleotide-A, High-Performance Liquid Chromatography (HPLC), Ultraviolet-Visible Spectrophotometry (UV-Vis), Liquid Chromatography-Mass Spectrometry (LC-MS), and lyophilization were used. Chromatographic data were collected with a semi-prep HPLC system, quantified with the UV-Vis technique, and validated with the LC-MS method. The most optimized parameters found to obtain the purity of 93.0% are 40 mM triethylammonium bicarbonate (TEAB) buffer with pH 7, which is approximately 6.0% higher than the reported method of which the purity is 87.0%. However, the yield under these conditions was reduced by about 5%. The worst possible optimized settings that resulted in the lowest purity (84.0%) and yield (69.0%) are 10 mM ammonium acetate (NH<sub>4</sub>CH<sub>3</sub>CO<sub>2</sub>) with pH 7.
文摘An efficient one-pot synthesis of 2,4,6-triarylpyridines has been described.This involves the three-component reaction of aldehydes,ketones and ammonium acetate in the presence of a catalytic amount of wet 2,4,6-trichloro-1,3,5-triazine(TCT) under solvent-free condition at 130℃.
文摘A series of 1,4-dihydropyridines have been prepared by a one-pot condensation of aldehydes,ethyl acetoacetate,and ammonium acetate in the presence of a heterogeneous catalyst silica sulfuric acid at room temperature under solvent-free condition. This new protocol has the advantage of short reaction time and excellent yields,and is an environmentally benign route to the synthesis of 1,4-dihydropyridines.
文摘A simple and efficient method has been developed;benzil/benzoin undergoes smooth condensation with various substituted aldehyde and ammonium acetate in the presence of potassium dihydrogen phosphate(KH;PO;) under mild reaction conditions to afford the corresponding trisubstituted imidazole in excellent yields.The method for synthesis of product,the reaction mixture was reflux in ethanol for 40-90 min.The present method is simple,efficient,and cost-effective.
文摘A simple one-pot synthetic method for the preparation of 2,4,5-triaryl-lH-imidazoles from benzoin or benzil, ammonium acetate, aromatic aldehydes, and ZrOCl2-8H2O catalyst is described. The ZrOCl2-8H2O catalyst was found to be equally effective for aromatic and heteroaromatic aldehydes and also for the preparation of substituted 1,4-di(4,5-diphenylimidazol-yl) benzene.
文摘Twenty 2,3-disubstituted-4(3H)-quinazolinones were synthesed by one-pot three-component method with isa- toic anhydride, orthoesters and amines as raw materials in the presence of KAI(SO4)2·12H2O (Alum) under micro- wave irradiation and solvent-free conditions. 6-Bromo-2-propyl-3-p-tolylquinazolin-4(3H)-one (4m), 6-bromo-2- methyl-3-phenethylquinazolin-4(3H)-one (4n) and 6-bromo-2-ethyl-3-phenethylquinazolin-4(3H)-one (40) were characterized by IR, 1H NMR, 13C NMR and elemental analysis.
基金This work was financially supported by the Natural Science Foundation of Henan Province(No.132300410319)and Luoyang Normal University.
文摘A facile synthesis of benzofuro[2,3-c]pyridines has been achieved under mild conditions by using ammonium acetate as the nitrogen source through intramolecular cascade annulation.This reaction could efficiently construct pyridine ring and furan ring in one step.Moreover,the key annulation step was demonstrated through dihydrobenzofuran intermediates.
文摘Various 2-phenylimidazo [4,5-f] [1,10] phenanthrolines were synthesized from potassium ferro-cyanide trihydrate (KFCT) complex catalyzed three component reaction of 1,10-phenanthroline-5,6-dione, aromatic aldehydes and ammonium acetate at room temperature in excellent isolated yield. This is a simple and straight forward, high yielding, not involving any hazardous or expensive catalyst method.