三氯化镧催化一锅法合成3,4-二氢嘧啶-2-酮

二氢嘧啶酮;三氯化镧催化一锅法合成3;4-二氢嘧啶-2-酮     

硅胶硫酸:一种在温和及无溶剂条件下一锅法合成1,4-二氢吡啶的高效多相催化剂(英文)

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.     

微波催化固相法合成3,4-二氢嘧啶-2(1H)-酮

在固相无溶剂条件下,使用微波辐射技术,由β－酮酸酯、芳香醛、脲合成了一系列3,4－二氢嘧啶－2（1H）－酮,实验简单方便,产率高,纯度高。     

(英)硫酸氢钾高效催化一锅法合成5-未取代的3,4-二氢嘧啶-2(1H)-酮

无溶剂条件下,硫酸氢钾可有效催化芳香醛、苯乙酮衍生物和脲的三组分"一锅法"Biginelli反应来合成5-未取代的3,4-二氢嘧啶-2(1H)-酮。确定了优化反应条件。产品结构经IR、1H NMR、MS和元素分析进行表征。     

Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Using Ce(SO4)2-SiO2 as a Heterogeneous and Recyclable Catalyst

A simple and efficient synthesis of 3,4-dihydropyrimidinones or thiones is described, using silica-supported ceric sulfate [Ce(SO₄)₂-SiO₂] as a heterogeneous catalyst from an aldehyde, 1,3-dicarbonyl compound, and urea or thiourea at 110 °C under solvent-free conditions. Compared with the classical Biginelli reaction, this new method consistently has better yields, short reaction time, easy separation, and tolerance toward various functional groups.     

PPA-SiO_2 as a Heterogeneous Catalyst for Efficient Synthesis of 2-Substituted-1,2,3,4-tetrahydro-4-quinazolinones under Solvent-free Conditions

Silica‐supported polyphosphoric acid (PPA‐SiO₂) catalyzed efficiently the reaction of anthranilamide with aryl aldehydes or ketones under solvent‐free conditions to afford the corresponding 1,2,3,4‐tetrahydro‐4‐quinazolinone derivatives. This work consistently has the advantages of excellent yields, short reaction time, simple experimental and work‐up procedures. The heterogeneous catalyst could be recovered and recycled for several times without any loss of its activity.     

以磷酸二氢铵为催化剂一锅法合成 3,4-二氢嘧啶-2-酮(英文)

A one-pot three component Biginelli condensation of different substituted aromatic and aliphatic aldehydes with ethyl acetoacetate and urea to the respective 3,4-dihydropyrimidin-2-( 1H)-ones under sol...     

NiCl2·6H2O催化的Biginelli反应－－一锅法合成3，4－二氢嘧啶－2－酮

六水合氯化镍催化下，β－酮酸酯、芳香醛和脲在无水乙醇中进行环化缩合反 应，合成了3，4－二氢嘧啶－2－酮衍生物，改进了Biginelli反应，缩短了反应时 间，且操作简便、产率高。     

新型无毒离子液体催化“一锅煮”合成3,4-二氢嘧啶-2(1H)-酮

利用新型无毒离子液体(BMImSac)作催化剂, 芳香醛、1, 3-二羰基化合物和尿素或硫脲三组分“一锅煮”合成了3,4-二氢嘧啶-2(1H)-酮. 与传统方法相比, 该法是一种操作简单、产率高、用时少的环境友好方法.     

One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones and Their Sulfur Derivatives with H2SO4 Supported on Silica Gel or Alumina

The one-pot condensation of aromatic aldehydes, β-dicarbonyl compounds, and urea or thiourea in the presence of H₂SO₄ supported on silica gel or alumina (80% m/m) in refluxing n-hexane produces 3,4-dihydropyrimidin-2(1H)-ones and their sulfur derivatives in high to excellent yields.     

微波辐射下FeCl3·6H2O催化绿色合成3,4-二氢嘧啶-2-酮

在微波辐射下,仅以六水合三氯化铁为催化剂,将芳香醛、β-二羰基化合物和脲(物质的量比为1:1.5:1.5)在无水乙醇中回流,高效地合成了3,4-二氢嘧啶-2-酮,反应时间4～6min,操作简便,环境友好.     

Microwave-Promoted Synthesis of 3,4-Dihydropyrimidin-2(1H)-(thio)ones Using IL-ONO as Recyclable Base Catalyst Under Solvent-Free Conditions

A mild, efficient, and solvent-free microwave (MW)–promoted Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-(thio)ones in nitrite ionic liquid (IL-ONO) is described. This ionic liquid is a weak Lewis base catalyst, which can be easily recovered and reused in several runs. The satisfactory results were obtained with good yields and short reaction time, using a simple experimental procedure.     

Simple and Efficient Synthesis of 2-Aryl-2,3-Dihydroquinolin-4(1H)-ones Using Silica Chloride as a New Catalyst Under Solvent-Free Conditions

A mild, efficient, and high-yielding method for the synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones from their corresponding 2-amino chalcones using silica chloride (SiO₂Cl) under solvent-free conditions is described. A series of 2-aryl-2,3-dihydroquinolin-4(1H)-ones containing both electron-donating and electron-withdrawing substituents were synthesized.     

Synthesis of 4-Alkynyl-substituted 3,4-Dihydropyrimidin-2(1H)-ones

4-Alkynyl-3,4-dihydropyrimidin-2-(1H)-ones were synthesized by a one-pot reaction of propynals, ethyl acetoacetate, and urea. The yields of acetylenic dihydropyrimidinones depend significantly upon the propynal structure and catalyst type. A comparative study of the catalysts revealed an important advantage of polyphosphate ester in tetrahydrofuran in comparison with hydrochloric acid in methanol or trimethylchlorosilane in dimethylformamide, allowing the preparation of target compounds in good or moderate yields.     

Borax: An Ecofriendly and Efficient Catalyst for One-Pot Synthesis of 3,4-Dihydropyrimidine-2(1H)-ones under Solvent-Free Conditions

Borax in the presence of a very small amount of 5 M sulfuric acid efficiently catalyses the three-component condensation of an aldehyde, β-ketoester, and urea or thiourea to afford the corresponding 3,4-dihydropyrimidin-2(1H)-ones or 3,4-dihydropyrimidin-2(1H)-thiones in good to excellent yields under solvent-free conditions at 80 °C. Compared with the classical Biginelli reaction conditions, this new method has the advantage of excellent yield, short reaction time (1–2 h), easy workup, and no use of volatile organic solvent.     

以金属硫酸氢盐为催化剂在无溶剂条件下高效合成3,4-二氢嘧啶-2(1H)-酮

以金属硫酸氢盐M(HSO4)n(Ca(HSO4)2,Zn(HSO4)2和过硫酸氢钾制剂oxone○R)为催化剂催化醛、1,3-二羰基化合物和尿素进行缩合反应,在90℃及无溶剂的条件下高收率、一锅法合成了3,4-二氢嘧啶-2(1H)-酮.     

硅胶固载硫酸镧催化一锅法合成3,4-二氢嘧啶-2(1H)-酮

以硅胶固载硫酸镧作为催化剂,由芳香醛、β-酮酸酯和脲(硫脲)合成了相应的3,4-二氢嘧啶-2(1H)-酮化合物,考察了苯甲醛、乙酰乙酸乙酯、脲三组分发生Biginelli反应时的催化剂用量、反应物物质的量比、反应时间及催化剂重复使用对反应收率的影响;并利用核磁共振谱(1H NMR)和红外光谱(IR)表征了合成产物的结构...     

可膨胀石墨催化的一锅法合成3,4-二氢嘧啶-2-酮衍生物

在可膨胀石墨催化下, 由芳香醛、β-酮酸酯和尿素(摩尔比1∶1∶1.5)三组分缩合制备3,4-二氢嘧啶-2-酮衍生物, 反应时间1.5～2 h, 产率可达72%～93%, 且催化剂可回收重复利用. 产物的结构经¹H NMR, IR确证.     

微波辐射下FeCl3•6H2O催化绿色合成3,4-二氢嘧啶-2-酮

在微波辐射下, 仅以六水合三氯化铁为催化剂, 将芳香醛、β-二羰基化合物和脲(物质的量比为1∶1.5∶1.5)在无水乙醇中回流, 高效地合成了3,4-二氢嘧啶-2-酮, 反应时间4～6 min, 操作简便, 环境友好.     

无机锌盐催化脂肪醛的Biginelli反应

以无水乙醇为溶剂, 在回流温度下, 考察了四种无机锌盐[Zn(NO₃)₂, ZnSO₄, ZnCl₂及Zn(OAc)₂]催化脂肪醛的Biginelli反应的催化能力, 所用原料为7种脂肪醛、1,3-二羰基化合物和脲. 实验结果表明硝酸锌的催化效果强于其它三种无机锌盐, 产率最高可以达到94%. FTIR和¹H NMR分析结果证实了所合成的目标产物. 该反应操作简单、催化剂廉价易得.