氯化镉催化三组分“一锅法”合成4,6-二芳基-3,4-二氢嘧啶-2(1H)-酮的研究

在氯化镉催化作用下,以环己烷为溶剂,芳香醛、芳香酮和脲三组分"一锅法"合成了一系列4,6-二芳基-3,4-二氢嘧啶-2(1H)-酮化合物。考察了溶剂和催化剂用量对产率的影响。通过IR、1H NMR、13C NMR和元素分析对产品结构进行了表征。该合成方法具有操作简单、反应时间短、反应条件温和,产率高等优点。     

无溶剂条件下对甲基苯磺酸铝高效催化合成4,6-二芳基-3,4-二氢嘧啶-2(1H)-酮

以芳香醛、芳香酮和尿素为原料,对甲基苯磺酸铝为催化剂,在90_oC、无溶剂条件下“一锅法”反应,高效合成了一系列4,6-二芳基-3,4-二氢嘧啶-2(1H)-酮。产品结构通过IR,₁H NMR,₁₃C NMR和元素分析进行了表征。该方法具有操作简单、反应时间短、产率高、反应条件温和、不使用任何有机溶剂、催化剂廉价易得且可重复使用等优点,为标题化合物的合成提供了一种简便高效的绿色新途径。     

New three-component cyclocondensation reaction: microwave-assisted one-pot synthesis of 5-unsubstituted-3,4-dihydropyrimidin-2(1H)-ones under solvent-free conditions

Sixteen 5-unsubstituted-3,4-dihydropyrimidin-2(1H)-ones have been synthesized by microwave-assisted Biginelli reactions in a short and concise manner employing ZnI₂ as a catalyst under solvent-free conditions. All products were identified by IR, NMR, elemental analysis and HRMS. The advantages of this novel protocol include the excellent yield, operational simplicity, short time and the avoidance of the use of organic solvents and expensive catalysts.     

Zinc perchlorate catalyzed one-pot synthesis of 3,4-dihydropyrimidinones under solvent-free conditions

Abstract

In this paper, we report zinc perchlorate hexahydrate [Zn(ClO₄)₂?6H₂O] as a highly effective catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones under solvent-free conditions. These improved reaction conditions allow the preparation of a wide variety of substituted dihydropyrimidinones in high yields and purity under mild reaction conditions. Compared with the classical Biginelli reaction, this method has the advantage of excellent yields and short reaction time in solvent-free conditions.     

A Set of phenyl sulfonate metal coordination complexes triggered Biginelli reaction for the high efficient synthesis of 3,4-dihydropyrimidin-2(1H)-ones under solvent-free conditions

Three new metal coordination complexes, namely, [Co ( DPE )(H₂O)₄]( DPE )( BS )₂ ( 1 ), [Co ( DPE )₂(H₂O)₄]( ABS )₂ ( 2 ), [Co ( DPE )(H₂O)₄]( MBS )₂(CH₃OH)₂ ( 3 ) [ DPE = (E)-1,2-di (pyridin-4-yl) ethene, BS = phenyl sulfonic acid, ABS = p-aminobenzene sulfonic acid, MBS = p-methylbenzene sulfonic acid] were obtained under hydrothermal conditions. Complexes 1 - 3 were structurally characterized by X-ray single-crystal diffraction, powder X-ray diffraction and IR. Complexes 1 and 3 exhibit a one-dimensional chain structure, and complex 2 does a zero-dimensional one. These three complexes further generate a three-dimensional supramolecular architecture via strong hydrogen bonding interactions and packing interactions. These three metal coordination complexes show high catalytic performance for green synthesis of a variety of 3,4-dihydropyrimidin-2(1H)-ones through the Biginelli reactions, which show several advantages such as excellent yields, short reaction times, eco-friendly synthesis conditions, and simple isolated workup procedure. Interestingly, the order of catalytic activities for these catalysts is the following: 3 > 1 > 2 , which can be ascribed to the acidities and hydrophobic interactions of phenyl sulfonate groups.     

邻甲基苯磺酸铜催化"一锅法"合成3,4-二氢嘧啶-2(1H)-酮

二氢嘧啶酮(DHPMs)及其衍生物具有广泛的生物活性,如抗病毒、抗肿瘤、抗癌、抗高血压及消炎等作用[1].此外,DHPMs及其衍生物作为钙通道阻滞剂、α1a-对抗剂和神经肽Y的对抗剂,显示出良好的药理活性[2].更重要的是,最近几种含二氢嘧啶酮-5-羧酸盐的海洋生物碱被成功分离出来,并表现出重要的生物学性质[3],某些可以阻止HIVgp-120-CD4键的形成,是一种潜在的HIV抑制剂[4].因此,对DHPMs及其衍生物的研究成为生物活性有机杂环化合物的研究热点之一.     

无溶剂条件下勃姆石纳米粒子锅催化多组分合成3,4-二氢嘧啶-2-(1H)酮简

A simple, green, and efficient synthesis protocol for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones using boehmite nanoparticles as catalyst was developed. It did not use any toxic metal catalysts or corrosive acidic reagents. The method gave good to excellent yields and has short reaction time, operational simplicity, and a recyclable catalyst.     

Three-components condensation catalyzed by molecular iodine for the synthesis of 2,4,6-triarylpyridines and 5-unsubstituted-3,4-dihydropyrimidin-2(1H)-ones under solvent-free conditions

Abstract  One-pot, three-components synthesis of 2,4,6-triarylpyridines and 5-unsubstituted-3,4-dihydropyrimidin-2(1H)-ones was performed under solvent-free conditions using molecular iodine as the catalyst in moderate to good product yields. Graphical abstract        

CoCl2·6H2O催化合成3,4-二氢嘧啶-2-酮衍生物

3 ,4 二氢嘧啶 2 酮类化合物可用作钙拮抗剂、降压剂、α1ａ 拮抗物等而成为近年来生物活性有机杂环化合物研究的热点之一[1 ] 。通常该类化合物是用Ｂｉｇｉｎｅｌｉ[2 ,3] 反应得到的。为了提高其产率 ,人们作了大量的研究工作[4,1 1 ] 。本文利用Ｃｏ Ｃｌ2 6Ｈ2 Ｏ作催化剂 ,乙醇作溶剂 ,乙酰乙酸乙酯、芳香醛和脲一锅煮合成 3,4 二氢嘧啶 2 酮 ,同时考查了芳香醛的取代基及乙酰丙酮对产物收率的影响。反应方程式如下 :1　实验部分1 1　仪器与试剂熔点用毛细管法测定 ,温度计未校正。Ｅ ＱＵＩＮＯＸ5 5红外光谱仪 (ＫＢｒ压片 ) ;…     

Cost-effective ionic liquid for environmentally friendly synthesis of 3,4-dihydropyrimidin-2(1H)-ones

Abstract

A simple, efficient and environmentally friendly process for synthesis of 3,4-dihydropyrimidinones using a one-pot three-component condensation of aromatic aldehydes, β-dicarbonyl compounds, and urea/thiourea is discussed. The cost-effective, new generation ionic liquid (IL), tri-(2-hydroxyethyl) ammonium acetate was used as both solvent and catalyst. The reactions were carried out using both conventional heating and microwave energy. Application of IL technology with microwave energy represents an attractive and rapid alternative to the conventional acid–base catalyzed thermal processes.     

TaBr5-catalyzed Biginelli reaction: one-pot synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones under solvent-free conditions

An efficient TaBr₅ (5-10 mol %)-catalyzed Biginelli reaction under solvent-free conditions for one-pot syntheses of 3,4-dihydropyrimidin-2-(1H)-ones (DHPMs) and their thione analogs is reported. The catalyst is stable at room temperature and employed under mild and environmentally friendly conditions.     

Synthesis of some new bis-3,4-dihydropyrimidin-2(1H)-ones by using silica-supported tin chloride and titanium tetrachloride

<正>Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions.     

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.     

Synthesis of 5-Cinnamoyl-3,4-dihydropyrimidine-2(1H)-ones

Two different approaches to the synthesis of 1-unsubstituted 5-cinnamoyl-3,4-dihydropyrimidine-2(1H)-ones have been developed. The first includes N(1)-protection of the starting 5-acetyl-3,4-dihydropyrimidine-2(1H)-one, further Claisen–Schmidt reaction, and cleavage of the protecting group. The second approach consists of one-pot condensation of urea, aldehyde, and cinnamoylacetone as dicarbonyl component. The 5-cinnamoylderivative synthesis starting from 5-acetyl-1,3-dialkyl-3,4-dihydropyrimidine-2(1H)-ones is also shown.     

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.     

Al(HSO4)3 and Al2O3-SO3H as Efficient Catalysts for Modified Preparation of 3,4-Dihydropyrimidin-2 (1H)-ones/thiones

An environmentally friendly procedure for the preparation of dihydropyrimidinone derivatives or their sulfur analogues under thermal solvent-free conditions in the presence of aluminium hydrogen sulfate [Al(HSO₄)₃] and alumina sulfuric acid (Al₂O₃-SO₃H) as heterogeneous catalysts was developed.     

Strontium chloride-catalyzed one-pot synthesis of 4(3H)- quinazolinones under solvent-free conditions

<正>Strontium chloride was used as an efficient and recyclable catalyst in one-pot condensation of anthranilic acid,ortho esters and amines leading to the formation of 4(3H)-quinazolinone derivatives in good yields at room temperature under solvent-free conditions.     

One-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones,thiones and 2-selenoxo DHPMs using 1-butyl-3-methylimidazolium hydrogen sulfate as non-halogenated ionic liquid

Abstract

1-Butyl-3-methylimidazolium hydrogen sulfate ([BMIM][HSO₄]) as a non-halogenated ionic liquid (IL) was used for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and thiones or 2-selenoxo DHPMs in a Biginelli type multi-component reaction. By using this ionic liquid, the reaction time was significantly reduced and the products were obtained in good to high yields. Also, in this method, the synthesis of novel 2-selenoxo DHPMs is introduced in the presence of this ionic liquid and their structures were determined by ¹H and ¹³C NMR, FT-IR, and Elemental analysis.     

CoNiFe2O4@Silica-SO3H nanoparticles: New recyclable magnetic nanocatalyst for the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones under solvent-free conditions

A useful and green synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones derivatives were achieved by one-pot cyclocondensation between substituted aryl aldehydes, diketone/ketoester, and urea/thiourea using magnetic CoNiFe₂O₄@Silica-SO₃H nanoparticles under solvent-free condition. The choice of this approach showed essential advantages such as short reaction time, simple work-up procedure, high activity of the catalyst, high yield of the reaction products, the magnetic properties of the catalyst, and environmentally amiable conditions. In addition, the catalyst recovered and reused four times without notable loss of its activity. The magnetic CoNiFe₂O₄@Silica-SO₃H nanoparticles were described by Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction spectroscopy, and vibrating sample magnetometer. The products were obtained with excellent yields (88–98%). The formation of the products was confirmed and identified with their physical properties (melting points), the FT-IR, ¹H NMR, ¹³C NMR, mass spectrometry, and the elemental analysis.