利用三溴化铟催化的Biginelli反应原位合成3,4-二氢嘧啶-2-酮

一些二氢嘧啶酮衍生物具有重要的药物活性 ,可用作钙拮抗剂、降压剂和α1- 1 - a-拮抗剂 [1] .目前 ,从海洋生物中分离得到的一些具有生物活性的生物碱也具有二氢嘧啶酮的核 [2 ] .因此 ,近年来 ,这类化合物的合成已引起人们的极大兴趣 .文献 [3 ]采用乙酰乙酸乙酯、苯甲醛和脲在强酸性条件下进行原位缩合 ,得到二氢嘧啶酮的衍生物 ,但是该反应的产率不高 .三溴化铟作为一个温和的路易斯酸 [4 ,5] ,可以高效地催化此类反应 .在这一催化体系中 ,不仅 β-酮酸酯可以发生缩合反应 ,而且相对困难的 β-二酮也可以发生此类反应 ,使一些在传统 Bi…     

SmI2催化合成3,4-二氢嘧啶-2-酮衍生物

3,4-二氢嘧啶-2-酮衍生物是一类具有生物活性的杂环化合物,在作为钙拮抗剂、降压剂、α1-1-a拮抗物等方面已有广泛的应用.该类化合物的合成法近十年来一直是生物活性杂环化合物领域研究的热点之一.Lewis酸催化的Biginelli反应是"一锅化"得到3,4-二氢嘧啶-2-酮衍生物的有效方法[1-5].我们以价廉易得的SmI2成功催化Biginelli反应,生成多个3,4-二氢嘧啶-2-酮衍生物.该反应无需反应溶剂,产率中等到高,且适用底物范围较广.     

对映纯3,4-二氢嘧啶酮衍生物的合成研究进展

3,4-二氢嘧啶酮本身是不对称分子,但绝大多数Biginelli反应得到的都是外消旋的3,4-二氢嘧啶酮类化合物.大量研究表明3,4-二氢嘧啶酮的C(4)立体中心的绝对构型对其生物活性有重要影响.主要归纳了获得对映纯3,4-二氢嘧啶酮类化合物的新发展,特别是不对称催化Biginelli反应合成此类化合物的文献方法.     

含有异(口恶)唑的S-三唑[3,4-b]-1,3,4-噻二嗪、咪唑[2,1-b]-1,3,4-噻二唑和咪唑[2,1-b]-1,3,4-(口恶)二唑衍生物的合成

异噁唑衍生物作为一类重要的生物活性物质[1,2],其合成一直受到人们的关注,其中德国HMR公司开发研制的新型抗内风湿性关节炎药来氟米特(Leftunomide)已于1998年在美国率先上市,该药还具有很好的免疫调节作用[3].7H-均三唑[3,4-b]-1,3,4-噻二嗪、咪唑并[2,1-b]噻唑和咪唑并[2,1-b]-1,3,4-噻二唑衍生物均表现出广谱的生物活性[4～6].     

2-氨基-4H-咪唑啉-4-酮衍生物的快速平行合成法

咪唑啉酮衍生物是一类具有良好生物活性和药理活性的杂环化合物 [1,2 ] ,尤其是一些 2 -氨基咪唑啉酮表现出良好的杀菌、抗炎及抗癌活性 [3 ,4 ] .从自然界如一些海洋生物中可分离得到含 2 -氨基咪唑啉酮结构的生物碱 [5,6] .最近 ,组合化学方法广泛地应用于有机合成 ,它包括固相合成法和液相合成法[7～ 9] .我们曾应用氮杂 Wittig反应制得 2 -氨基取代咪唑啉酮衍生物 ,部分化合物表现出一定的抑菌活性 [10 ,11] .本文进一步报道应用液相平行反应法快速合成 2 -氨基 - 4H-咪唑啉 - 4-酮衍生物 (4) .该方法应用烯基膦亚胺 1与苯基异氰酸酯的…     

4,5-二氢咪唑并[1,2-b]-1′,2′,4′-三唑-4-酮衍生物的合成与杀菌活性

应用芳基异氰酸酯与烯基膦亚胺1的氮杂Wittig反应,得到的碳二亚胺2,再与水合肼作用得到氨基咪唑啉酮衍生物4.而后用4与芳基异氰酸酯(或酰氯)、三苯基膦、六氯乙烷和三乙胺"一锅"反应,得到4,5-二氢咪唑并[1,2-b]-1′,2′,4′-三唑-4-酮衍生物6或7.探讨了所合成新型稠杂环化合物的生物活性,结果表明部分化合物表现出良好的杀菌活性.如7c在50 mg/L浓度时,对棉花枯萎菌、稻瘟菌、黄瓜灰霉菌和油菜菌核菌的抑制率均达100%.     

二氢吲哚-2,3-二酮衍生物抑菌活性研究进展

二氢吲哚-2,3-二酮是一种结构简单且应用广泛的药物小分子,其衍生物的合成、结构和药理活性等备受关注。已有报道表明二氢吲哚-2,3-二酮具有抗菌、抗衰老、降血脂、抗癫痫、抗病毒等多种生物活性。本文主要围绕抑菌生物活性,对国内外关于二氢吲哚-2,3-二酮类化合物的构效关系进行分析总结,为后期该类新型抗菌化合物的设计合成提供参考。     

2,3-二氢吡喃并[2,3-f]异喹啉-4-酮及其衍生物的合成

色满酮-4和苯并色满酮-4及其衍生物,已有大量报道。也发现了其中不少衍生物具有重要的药理作用。但对杂环并色满酮-4及其衍生物的合成、性质的研究则很少。2,3-二氢吡喃并[2,3-f]喹啉-4-酮的合成已有记载,但尚未见相应异喹啉-4-酮及其衍生物的报道。我们以5-羟基异喹啉为起始原料,经氰乙     

4,5-二氢咪唑并[1,2-b]-1',2',4'-三唑-4-酮衍生物的合成与杀菌活性

应用芳基异氰酸酯与烯基膦亚胺1的氮杂Wittig反应,得到的碳二亚胺2,再与水合肼作用得到氨基咪唑啉酮衍生物4.而后用4与芳基异氰酸酯(或酰氯)、三苯基膦、六氯乙烷和三乙胺"一锅"反应,得到4,5-二氢咪唑并[1,2-b]-1',2',4'-三唑-4-酮衍生物6或7.探讨了所合成新型稠杂环化合物的生物活性,结果表明部分化合物表现出良好的杀菌活性.如7c在50mg/L浓度时,对棉花枯萎菌、稻瘟菌、黄瓜灰霉菌和油菜菌核菌的抑制率均达100%.     

一锅法合成N1,N3-二烷基取代-3,4-二氢嘧啶-2(1H)-酮及其抗菌活性研究（英文）

在温和的相转移催化剂存在下,合成得到一系列N1,N3-二烷基取代-3,4-二氢嘧啶-2(1H)-酮,并测定了取代二氢嘧啶酮对灰霉菌、小麦赤霉菌、辣椒疫霉病菌、油菜菌核病菌、水稻纹枯病菌、稻瘟病菌六种霉菌的抗菌活性。多数取代二氢嘧啶酮对后五种霉菌体现出不错的抗菌活性,特别是N原子上被(CH2)nBr取代的二烷基取代二氢嘧啶酮对于油菜菌核病菌、小麦赤霉菌以及辣椒疫霉病菌表现出不错的抗菌活性。数据表明,二氢嘧啶酮中嘧啶环和酯基上的取代基变化有助于改善嘧啶酮的抗菌活性。     

一个简单、环境友好的硅胶固载硫酸催化Biginelli反应体系(英文)

A protocol for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and-thiones was developed by means of a three-component condensation of an aldehyde,a β-dicarbonyl compound,and urea or thiourea in acetic acid catalyzed by silica-bonded S-sulfonic acid.Compared to the classical Biginelli reaction conditions,this new protocol has the advantages of consistently excellent yields and short reaction times.After the reaction,the catalyst could be recovered easily and reused with little change in its activity.     

Al2O3/MeSO3H: A Novel and Recyclable Catalyst for One-Pot Synthesis of 3,4-Dihydropyrimidinones or Their Sulfur Derivatives in Biginelli Condensation

Al₂O₃/CH₃SO₃H (AMA) is an efficient catalyst for the three-component condensation reaction of aldehyde, 1,3-dicarbonyl compound, and urea or thiourea to afford the corresponding 3,4-dihydropyrimidin-2-(1H)-ones in high isolated yield via this procedure, which works very effectively regardless of the electronic nature of the substituent on the ring, although electron-donating groups precipitate the rate of reaction. The catalyst is recyclable and stable at room temperature, and the reaction protocol is simple, is cost-effective, and gives good isolated yield with high purity.     

Synthesis of 3,4-dihydropyrimidin-2(1H)-ones catalyzed by nafion-H under ultrasound irradiation and solvent-free conditions

A novel synthesis of 3,4-dihydropyrimidin-2-(1H)-ones by one-pot cyclocondensation of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea using nafion-H as the catalyst under ultrasound irradiation and solvent-free conditions was developed. Compared with the classical Biginelli reactions, this method consistently enjoys the advantages of mild reaction conditions, excellent yields, easy work up and short reaction time.     

TETRABUTYLAMMONIUM HYDROGEN SULFATE: AN EFFICIENT CATALYST FOR THE SYNTHESIS OF 3,4-DIHYDROPYRIMIDIN-2(1H)-ONES UNDER SOLVENT-FREE CONDITIONS

Tetrabutylammonium hydrogen sulfate (TBAHS) as[3pc] a solid protic acid and phase-transfer reagent catalyzed the three-component condensation reactions of aldehydes, 1,3-dicarbonyl compounds, and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1H)-ones in high yields at 80°C.     

NaHSO4·H2O as a Heterogeneous Acidic Reagent for Mild and Convenient Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones and Their Sulfur Derivatives

One-pot cyclocondensation reaction of aromatic aldehydes, 1,3-dicarbonyl compounds and urea/thiourea in the presence of NaHSO₄·H₂O produced 4-aryl substituted 3,4-dihydropyrimidin-2(1H)-ones and their sulfur analogs in high to excellent yields. The reactions were carried out in refluxing n-hexane and were completed within 2.5–11 h.     

NaIO4-catalyzed one-pot synthesis of dihydropyrimidinones at room temperature under solvent-free conditions

Sodium periodate efficiently catalyzed the three-component Biginelli reaction of an aldehyde, α β-keto ester or β-keto ketone, and urea or thiourea at room temperature under solvent-free conditions and afforded the corresponding 3,4-dihydropyrimidine-2-(1H)-ones in excellent yields.     

Three-component,one-pot synthesis of 3,4-dihydropyrimidin-2-(1<Emphasis Type="Italic">H</Emphasis>)-ones catalyzed by bromodimethylsulfonium bromide

An efficient synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives by one-pot three-component condensation reaction between an alkyl or aryl aldehyde, a 1,3-dicarbonyl compound, and urea or thiourea in the presence of catalytic amount of bromodimethylsulfonium bromide has been developed. The condensation product was obtained in excellent yields in refluxing ethanol and easily separated from the reaction mixture and purified.     

磺化碳催化Biginelli反应一锅法合成3,4-二氢-2(1H)-酮和硫酮(英文)

A sulfonated carbon material was shown to be a highly efficient,eco-friendly,and recyclable solid acid catalyst for the Biginelli reaction of β-ketoester,aldehyde,and urea or thiourea under solvent-free conditions.It gave 3,4-dihydropyrimidin-2(1H)-ones and-thiones in good to excellent yields.This method has the advantages of a simple procedure with easy work-up,short reaction time,and high yields.The catalyst can be recycled after a simple work-up and was reused four times without substantial reduction in activity.     

Ammonium chloride-catalyzed one-pot synthesis of 3,4-dihydropyrimidin-2-(1H)-ones under solvent-free conditions

Ammonium chloride as a very inexpensive and readily available reagent, and efficiently catalyzes one-pot, three component, Biginelli condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions to afford the corresponding 3,4-dihydropyrimidin-2-(1H)-ones in high yields at 100°C.     

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.