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.     

Xanthan Sulfuric Acid: A New and Efficient Biosupported Solid Acid Catalyst for the Synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones

Xanthan sulfuric acid (XSA) is employed as a recyclable catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones. These syntheses were performed via a one-pot, three-component condensation of aldehydes, amines, and urea/thiourea under solvent-free conditions.     

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.     

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.     

(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。     

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.     

An efficient synthesis of 3,4-dihydropyrimidin-2(1H)-ones catalyzed by molten [Et3NH][HSO4]

A simple ammonium salt of sulfuric acid in molten state was used as a cheap and mild acidic ionic liquid for efficient synthesis of 3,4-dihydropyrimidin-2(1H)-ones in good to excellent yields.     

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.     

超声法合成3,4-二氢嘧啶-2(1H)-酮衍生物

以取代芳醛（1a~1h）,乙酰乙酸乙酯(2)和脲(3)为原料,MMT/CuCl₂为催化剂,乙醇为溶剂,在超声条件下经Beginelli反应合成了8个3,4-二氢嘧啶-2(1H)-酮衍生物（4a~4h）,其结构经¹H NMR和IR确证。以4a为例,分别采用单因素法和正交实验法研究了催化剂、溶剂、反应温度、超声时间和物料比r［n(1a): n(2) :n(3)］对4a产率的影响。结果表明：在最优反应条件(1a 2.4 mol, r=1.2 : 1.0 : 1.0, MMT/CuCl₂20 mol%, EtOH 1 mL,于90 ℃超声15 min)下,4a产率88.4%。 MMT/CuCl₂循环使用3次,产率基本不变。     

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.     

Biginelli 3,4-二氢嘧啶-2-酮衍生物的合成研究新进展

1893年, 意大利化学家Biginelli首次利用芳香醛、乙酰乙酸乙酯和尿素三组分“一锅煮法”合成了3,4-二氢嘧啶-2(1H)-酮. 此类化合物具有良好的生物活性和反应活性, 对近几年来有关Biginelli 3,4-二氢嘧啶-2(1H)-酮的衍生化反应、Biginelli不对称合成和Biginelli反应在天然产物合成中的应用研究进行了综述.     

Melamine trisulfonic acid:A new,efficient and recyclable catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones in the absence of solvent

Melamine trisulfonic acid(MTSA) can be used as an efficient and recyclable catalyst for the promotion of the synthesis of 3,4- dihydropyrimidin-2(1H)-ones/thiones(DHPMs) in the absence of solvent.All reactions were performed at 80℃in good to high yields.     

Environmentally Friendly Preparation of 3,4-Dihydropyrimidin-2(1H)-thiones Catalyzed by Al(H2PO4)3

An efficient, facile, simple, and green synthetic protocol for the Biginelli reaction has been developed for the preparation of 3,4-dihydropyrimidin-2(1H)-thione derivatives under thermal and microwave irradiation, solvent-free conditions, in the presence of aluminum hydrogen phosphate, Al(H₂PO₄)₃, as an environmentally friendly heterogeneous recyclable catalyst, in high to excellent yields and short reaction time. In addition, the catalyst could be easily recovered from the reaction mixture by simple filtration and reused several times without any loss of activity.     

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.     

A one-pot Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones catalyzed by triphenylphosphine as Lewis base

We report herein the use of triphenylphosphine (TPP) as a new catalyst for the one-pot Biginelli reaction coupling of β-ketoesters, aldehydes and urea (or thiourea) to afford the corresponding dihydropyrimidinones/thiones.     

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...     

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.     

1-Sulfopyridinium chloride:Green and expeditious ionic liquid for the one-pot synthesis of fused 3,4-dihydropyrimidin-2(1H)-ones and thiones under solvent-free conditions

1-Sulfopyridinium chloride portrayed as an efficient and recyclable ionic liquid for the synthesis of fused3,4-dihydropyrimidin-2(1H)-ones and thiones via a modified Biginelli reaction involving one-pot three component condensation of 6-methoxy-1-tetralone,arylaldehydes and urea/thiourea under solventfree conditions.Analytically pure products are formed within 10–20 min in excellent yields.