Synthesis of 4—Aryl—3,4—dihydropyrimidinones Using Microwaveassisted Solventless Biginelli Reaction

Ｉｎｔｒｏｄｕｃｔｉｏｎ4 Ａｒｙｌ 3,4 ｄｉｈｙｄｒｏｐｙｒｉｍｉｄｉｎｏｎｅｓ (4)ａｓａｃｏｒｅｗｅｒｅｏｂｓｅｒｖｅｄｉｎｓｏｍｅｂｉｏｌｏｇｉｃａｌｌｙｉｍｐｏｒｔａｎｔｃｏｍｐｏｕｎｄｓ .1Ｍｏｒｅｒｅｃｅｎｔｌｙ ,ｄｉｈｙｄｒｏｐｙｒｉｍｉｄｉｎｏｎｅｓａｒｅｓｈｏｗｎｔｏｂｅａｕｓｅｆｕｌｔｏｏｌｆｏｒｓｔｕｄｙｉｎｇｄｙｎａｍｉｃｃｅｌｌｕｌａｒｐｒｏｃｅｓｓａｎｄｃａｎｂｅｃｏｎｓｉｄｅｒｅｄａｓａｎｅｗｌｅａｄｆｏｒｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆａｎｔｉ ｃａｎｃｅｒｄｒｕｇ…     

Unprecedented single-pot protocol for the synthesis of N1, C6-linked bicyclic 3,4-dihydropyrimidinones via lithiation of Biginelli compounds

4-Aryl/alkyl-6-methyl-3,4-dihydropyrimidin-2(1H)-one ester derivatives readily undergo metalation at the C6 methyl (vinylogous ester) position along with two acidic NHs upon treatment with n-butyllithium at −10 °C. The trianion of DHPMs thus obtained react smoothly with various terminal dibromoalkanes to afford N1, C6-linked bicyclic DHPM derivatives, which represent key structural features of the medicinally potent marine alkaloids such as batzelladine A and crambescin A.     

3-芳基-6-对氯苯甲酰氨基均三唑并[3,4-b]-1,3,4-噻二唑的 合成及生物活性

利用3-芳基-4-氨基-5-巯基-1,2,4-均三唑和对氯苯甲酰异硫氰酸酯在乙腈中反应, 得到一系列3-芳基-6-对氯苯甲酰氨基均三唑并[3,4-b]-1,3,4-噻二唑, 用1H NMR, IR, MS和元素分析确定了其结构, 并对其进行了抑菌活性测试.     

Synthesis and analytical properties of 3,4-dihydroxybenzaldehyde guanylhydrazone (3,4-DBGH)

Synthesis and analytical properties of 3,4-dihydroxy-benzaldehyde guanylhydrazone are described. The reagent was tested with 43 cations but only Co(II), Fe(II), Fe(III), Mo(VI), W(VI) and V(V) gave colored complexes. Spectral characteristics of the reagent are presented. Procedure for a selective a determination of Co(II), a sensitive determination of Fe(III) and determination of Mo(VI), W(VI) and V(V) in presence of large amounts of Fe(III) are reported. The method was applied for the determination (a) of Co(II) in presence of other cations at excess (b) of Fe(III) in a city drinking water sample without preconcentration and (c) of Mo(VI) in a standard steel sample.     

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.     

Regioselective addition reactions at C-2 of 3,4-dihydropyrimidinones. Synthesis and evaluation of multifunctionalized tetrahydropyrimidines

Multifunctionalized tetrahydropyrimidines derivatives have been synthesized from Biginelli 3,4-dihydropyrimidin-2-(1H)-thiones (DHPMs) efficiently. The transformation includes desulfurization of DHPMs with Raney-Ni and subsequent regioselective C-2 functionalization using a variety of C-nucleophiles with simultaneous activation with ethyl chloroformate. Functionalized pyrimidine derivatives containing bulky substituents at C-2 of the pyrimidine ring are cytostatic.     

Green synthesis of 3,4-dihydropyrimidinones using nano Fe3O4@meglumine sulfonic acid as a new efficient solid acid catalyst under microwave irradiation

Design, synthesis and characterization of nano Fe₃O₄@meglumine sulfonic acid as a new solid acid catalyst for the simple and green one pot multicomponent synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones was studied. New solid acid catalyst was prepared through a clean and simple protocol and characterized using FTIR, VSM, TGA, SEM, elemental analysis (CHN) and XRD techniques. Heterogenization of homogeneous catalyst as a green approach is a useful method for enhancing the efficiency of catalyst. Presented study was a new method for attachment of homogeneous highly soluble catalyst (meglumine sulfate) to the magnetite nanoparticle surfaces for preparing a heterogeneous and effective catalyst. Obtained heterogeneous and reusable solid acid catalyst has high performance in the synthesis of Biginelli compounds. The reaction was performed under microwave irradiation as a rapid and green condition. Easy work up as well as excellent yield (90–98%) of products in short reaction times (40–200 s) and reusable catalyst are the main advantages of presented procedure. Reaction products were characterized in details using physical and chemical techniques such as melting point, ¹H NMR, ¹³C NMR and FTIR.     

水溶液中4-芳基-1,4-二氢吡啶衍生物的一步合成法

以芳醛、乙酰乙酸乙酯(或甲酯)、醋酸铵为原料在氯化三乙基苄基铵(TEBA)催化下在水中一步合成了4-芳基-1,4-二氢吡啶衍生物,该方法具有产率高、污染少、环境友好等特点.     

Synthesis and characterization of perfluorohexylated poly(3,4-ethylenedioxythiophene)

The perfluorohexylated 3,4-ethylenedioxythiophene 5 was prepared via Mitsunobu reaction of perfluorohexylatyed diol 2 with diethyl 3,4-dihydroxythiophenedicarboxylate followed by decarboxylation. The polymerization of 5 was conducted with both oxidative chemical and electrochemical polymerizations. The polymers were characterized by cyclic voltammogram, UV, IR, TGA and DSC.     

利用微波技术合成4-芳基-5-甲氧羰基-6-甲基3,4-二氢吡啶-2-酮

微波辐射;二氢吡啶酮;芳醛;麦氏酸;利用微波技术合成4-芳基-5-甲氧羰基-6-甲基3;4-二氢吡啶-2-酮     

Synthesis and characterization of monosubstituted and disubstituted poly(3,4‐propylenedioxythiophene) derivatives with high electrochromic contrast in the visible region

Monosubstituted and disubstituted 3,4‐propylenedioxythiophenes were synthesized and polymerized by both chemical and electrochemical methods. All the monomers were characterized for their molecular structures, and the polymers were characterized for their electrochemical properties. The disubstituted derivatives showed higher contrast than the corresponding monoalkyl derivatives. The highest electrochromic contrast of 89% was exhibited by a dibenzyl derivative, but the derivative was insoluble. On the other hand, the electrochemically polymerized dihexyl‐ and didodecyl‐substituted poly(3,4‐propylenedioxythiophene)s exhibited 74 and 77% electrochromic contrast, respectively, and were soluble. The molecular weights of the chemically and electrochemically synthesized polymers were analyzed by gel permeation chromatography. The chemically synthesized polymers showed higher molecular weights. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 419–428, 2005     

Synthesis of New 3,4-Disubstituted Furazans

A series of new 3,4-substituted furazans was synthesized on the basis of the mutual transformations of the functional groups in halogenomethyl and bisacyl derivatives of furazan.     

对硝基甲苯合成3,4-二甲基苯胺的研究

以对硝基甲苯为原料,经胺甲基化、水解、还原3步反应合成了目标化合物。通过单因素实验,分析每一步反应的关键影响因素,初步得到适宜的合成条件。最终产物的结构经核磁氢谱、质谱、元素分析进行确证,纯度经气相色谱分析。3,4-二甲基苯胺的总收率56.6%,纯度大于98.5%。该合成路线原料易得,成本较低,操作简单。     

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.     

(C5H6N4O)(C5H5N4O)3(C5H4N4O)[Bi2Cl11]Cl2 as a simple and efficient catalyst in Biginelli reaction

A highly efficient and facile procedure for the one‐pot three‐component synthesis of 3,4‐dihydropyrimidin‐2‐(1H )ones/thiones from the one‐pot condensation of aldehyde, β‐dicarbonyl compound and urea/thiourea was developed. The methodology is applicable to a wide range of substrates with high yield in the presence of (C₅H₆N₄O)(C₅H₅N₄O)₃(C₅H₄N₄O)[Bi₂Cl₁₁]Cl₂. The complex is an air‐stable, environmentally friendly and recoverable catalyst and can efficiently catalyze the Biginelli reaction. The catalyst has high catalytic efficiency with low catalyst loading, and can be recycled ten times with only a small loss of activity.     

基于3,4-吡唑二甲酸为配体的两个过渡金属配合物的合成、结构及荧光性质

以3,4-吡唑二甲酸(H3pdc)为配体分别与氯化铜、氯化镍反应,得到了2个过渡金属配合物:[M(H2pdc)2(H2O)2]·2H2O(M=Cu(1)和Ni(2)),用元素分析、红外光谱、X-单晶衍射结构分析、热重分析和荧光分析对其进行了表征。晶体结构分析表明配合物1和2均为单核结构,金属离子与来自2个H2pdc-中的2个N原子和2个羧基O原子,以及2个水分子中的2个O原子配位,形成六配位的八面体构型。配合物1和2中的独立结构单元[M(H2pdc)2(H2O)2]·2H2O通过3种分子间氢键(O-H…O,N-H…O和C-H…O)形成三维(3D)空间结构;此外我们还研究了配合物1和2的热稳定性和荧光性质。     

Polymer-Supported 4-Aminoformoyldiphenylammonium Triflate (PS-AFDPAT): An Effective and Recyclable Catalyst for the Biginelli Reaction

Polymer-supported 4-aminoformoyldiphenylammonium triflate (PS-AFDPAT) was used as an effective catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones (DHPMs) via the Biginelli reaction. This immobilized catalyst could be easily recovered by simple filtration and recycled for 10 runs without significant decrease of the catalytic activity.     

微波辐射下无溶剂合成4－芳基－5－乙氧羰基－6－甲基-3，4－二氢吡啶－2－酮

以芳醛、乙酰乙酸乙酯、麦氏酸和醋酸铵为原料，在无溶剂条件下用微波辐射 后合成了一系列4－芳基－5－乙氧羰基－6－甲基－3，4－二氧吡啶－2－酮。     

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.