Cu（I）-Catalyzed Synthesis of 2-Substituted Benzimidazoles from 2-lodoanilines and Amides

A novel and efficient approach to the synthesis of 2-substituted benzimidazoles has been developed via CuI/DMEDA-catalyzed coupling reaction and post-cyclization with glacial acetic acid from readily available 2-iodoanilines and amides. This method is suitable for the construction of a variety of benzimidazoles in moderate to good yields under short reaction times.

Search for New AntiphytovirucidesⅣ.Synthesis of 2-(2'-Hydroxyphenyl)-5(6)-substituted benzimidazole Derivatives

A convenient method to synthesize substituted 2 (2' hydroxyphenyl) benzimidazoles is reported. Six title compounds have been synthesized by the reaction of salicylic acid and 4 substituted o phenylenediamine in the presence pyridine POCl 3 . Three compounds were tested as plant virucide against tobacco mosaic virus and they exhibited some activities.

三维超分子化合物[2-(3-pyridyl)benzimidazoleH_2]_2^(4+)·[Cd_2Cl_8]^(4-)的水热合成、晶体结构及发光性质

将邻苯二胺、3-吡啶甲酸与二氯化镉在1∶1的盐酸溶液中经水热反应,合成了一种超分子化合物[2-(3-pyridyl)benzimidazoleH2]24+.[Cd2Cl8]4-。通过元素分析、红外光谱、热重对其结构和性质进行了表征,用X-射线单晶衍射测定了该化合物的晶体结构。化合物晶体为单斜晶系,P21/c空间群。超分子化合物中的Cd2+与其周围4个氯离子配位,构成畸变三角锥构型的离子[CdCl4]2-,2个配阴离子[CdCl4]2-之间通过双氯桥键[Cd-Cl-Cd]构成五配位双核镉髤四元环状结构,并与2个2-(3-吡啶基)苯并咪唑两价阳离子,通过静电引力、氢键及π-π堆积作用形成三维网状超分子化合物。荧光测试表明该化合物具有较好的光致发光性能。

离子化合物｛[2-(3′-pyridyl)benzimidazoleH_2]^(2+)·[SbCl_4]^-·Cl^-｝_4的水热合成、晶体结构及抑菌活性

A new ionic compound ｛[2-(3′-pyridyl)benzimidazoleH2]2+·[SbCl4]-·Cl-｝4 was synthesized by the hy- drothermal reaction of o-diaminobenzene, nicotinic acid with SbCl3 in 1∶1 HCl solution. The structure was charac- terized by chemical analysis, elemental analysis and IR patterns. The single crystal structure was determined by X-ray single crystal diffraction. It crystallizes in monoclinic system, space group P21/n with a=2.107 9(4) nm, b= 1.482 0(3) nm, c=2.113 4(4) nm, β=93.44(3)°, Z=4, V=6.590(2) nm3, Dc=2.001 g·cm-3, μ=2.480 mm-1, F(000)= 3840, R1=0.0468, wR2=0.1163. The single crystal structure indicates that the four chlorines coordinated to the antimony atom forms a distorted triangle bipyramid configuration together with the lone electron pair on the Sb atom. The [SbCl4]- to 2-(3′-pyridyl)benzimidazole cation and Cl- by weak interaction forms the ionic crystal. It has been proved that the title compound has antibacterial activity. CCDC: 283824.

Hydrothermal Synthesis,Crystal Structure and Fluorescence Spectrum Studies of a Supramolecular Compound {[2-(2-Pyridyl)benzimidazoleH_2]^(2+)·[SbCl_5]^(2-)}_2

A new supramolecular compound, { [2-（2-pyridyl）benzimidazoleH2]2＋.[SBC15]2-}2, was synthesized by the hydrothermal reaction of o-diaminobenzene, 2-pyridinecarboxylie acid and SbCl3 in 1：1 HC1 solution, and characterized by chemical analysis, elemental analysis, IR spectra, thermogravimetfic analysis and fluorescence spectra. The crystal structure was deter- mined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P211c, with a = 16.0397（13）, b = 14.3189（12）, c = 15.6370（13） A, β = 105.8980（10）°, V = 3454.0（5） A3, Z = 4, C24H22Cl10N6Sb2, Mr = 992.48, Dc = 1.909 g/cm3,/z = 2.366 mm-1, S = 1.010, F（000） = 1920, R = 0.0254 and wR = 0.0555. The coordination anion, [SbCl5]2- which is a distorted tetragonal pyramid, is composed by coordinating action with Sb3＋ ion and five adjacent chloride ions. Every four coordination anions of [SbCl5]2- form a biquaternion ring structure through the secondary bonding of Sb...Cl. Moreover, the compound adopts a three-dimensional network supramolecular structure because of the hydrogen bonds and π-π stacking between the rings and the 2-（2-pyridyl）benzimidazole divalent cations. The title compound also shows good fluorescent behaviors.

Glyoxylic acid as catalyst:A simple selective synthesis of 1,2-disubstituted benzimidazoles in aqueous media

Glyoxylic acid （5 mol%） performs as a novel highly water-soluble catalyst for the synthesis of 2-aryl-l-arylmethyl-lH- benzimidazoles from a wide range of substituted o-phenylenediamines and various substituted aldehydes in good to excellent isolated yields （85-95%） using water as solvent at ambient temperature. The remarkable advantages offered by this method are easily and inexpensive available catalyst, simple procedure, mild conditions, much faster （20--40 rain） reactions and excellent yields of products.

Synthesis and antibacterial activity of C-2(S)-substituted pleuromutilin derivatives

In order to probe the effect of C-2(S)-substituted groups in the antibacterial activity,a series of novel C-2(S)-substituted pleuromutilin analogues of SB-225586 were synthesized and evaluated for their in vitro antibacterial activity.The results of antibacterial activities indicated that C-2(S)-substituted pleuromutilin derivatives retained appreciable antibacterial activity,and the 2-fluorination compounds 6a and 6b are more potent than the corresponding 2-hydroxylation analogues 7a and 7b.

A simple and efficient synthesis of 2-substituted benzothiazoles catalyzed by H_2O_2/HCl

A simple and efficient procedure for the synthesis of substituted benzothiazoles through condensation of 2-aminothiophenol with aromatic aldehydes in the presence of H2O2/HCl system in ethanol at room temperature is described. The target compounds have been characterized by ^1H NMR, ^13C NMR, IR and MS. Short reaction time, easy and quick isolation of the products, and excellent yields are the main advantages of this procedure.

BF_3·OEt_2 Promoted Solvent-free Synthesis of Benzimidazole Derivatives

Differently substituted benzimidazoles have been synthesized in very good yields in solvent-free conditions from o-phenylenediamine and aldehydes in the presence of BF3·OEt2 as a catalyst. The method is applicable to aromatic, unsaturated and aliphatic aldehydes and to substituted o-phenylenediamines without significant differences.

Synthesis,Crystal Structure,Photophysical and Redox Properties of a Novel Ru(Ⅱ) Complex with Carbazole-grafted 2-(2-Pyridyl)benzimidazole

A novel Ru（Ⅱ） complex [（bpy）2Ru（PBC）]（PF6）2 （PBC = N-[4-（9-carbazole）butyl]-2-（2-pyridyl）benzimidazole） has been synthesized and verified by 1↑H NMR, elemental analysis and X-ray crystallography. The crystal （C48H40F12N8P2Ru, Mr = 1119.89） belongs to the triclinic system, space group P1, with a = 13.128（4）, b = 13.814（4）, c = 14.184（4） A, α = 84.112（6）, β = 88.473（6）, γ = 78.196（6）°, Z = 2, V = 2504.6（13）A^3, Dc = 1.485 g/cm^3, F（000） = 1132, R = 0.0750 and wR = 0.1896. The Ru atom adopts a distorted-octahedral coordination geometry with the bond distances and bond angles falling in normal ranges. The complex shows an intense metal-to-ligand charge transfer （1MLCT） （dπ（Ru） →π＊（L）） transition （ε ~1.2×10^4 dm^3mol^-1cm^-1） at 457 nm in the UV-Vis absorption spectrum and a strong red phosphorescence at 632 nm in the CH3CN solution at ambient temperature. An efficient intramolecular energy transfer process from the carbazole unit to the [（bpy）2Ru（PB）]^2＋ emissive center exists by selective optical-simulation. Its electrochemical behavior shows multiplicate redox processes based on the metal center, the grafting carbazole moiety and the 2-（2-pyridyl）benzimidazole unit.

Hydrothermal Synthesis,Crystal Structure and Fluorescence Spectrum Studies of a Novel Supramolecular Compound {[2-(2-Pyridyl)benzimidazoleH_2]_2·[BiCl_6]·Cl}

A novel supramolecular compound,{[2-（2-pyridyl）benzimidazoleH2]2·[BiCl6]·Cl},was synthesized by the hydrothermal reaction of o-phenylenediamine and α-pyridinecarboxylic acid with BiCl3 in 6.0 mol·L-1 HCl solution,and characterized by elemental analysis,IR,X-ray single-crystal diffraction and photoluminescence spectroscopy.The crystal （C24H22N6Cl7Bi,Mr= 851.61） belongs to the triclinic system,space group P1 with a =7.2887（18）,b =9.548（2）,c= 12.469（3）,α=85.306（4）,β=82.814（4）,γ=71.349（4）°,Z=1,V=814.9（3）3,Dc=1.735 g/cm3,μ（MoKα）=6.007 mm-1,F（000）=410,R=0.0307 and wR=0.0787.The bismuth ion and six chlorine ions construct a distorted octahedral configuration.The three-dimensional supramolecular network is built from electrostatic attractions,hydrogen bonds and π-π interaction between the BiCl6 anion,Cl anion and [2-（2-pyridyl）benzimidazoleH2] cation.The photoluminescence spectroscopy study shows that the title compound has a blue fluorescent emission at 450 nm in the solid state.

Syntheses and Crystal Structures of Two New Supramolecular Architectures Constructed from the Main Group Metal Chloride and Protonated 2-(3-Pyridyl)benzimidazole

The reactions of SbCl3 and HgCl2 with 2-（3-pyridyl）benzimidazole （PyBIm） in solution acidified with HCl have been investigated. The PyBIm ligands are protonated into 2-（3-pyridinio）benzimidazolium （H2PyBIm） cations and the corresponding metal ions are bonded with chloride atoms into coordination anions, forming two new coordination compounds, namely, （H2PyBIm）（SbCl5） 1 and （H2PyBIm）2（Hg2Cl8） 2. Both compounds were characterized by X-ray crystallography. Crystal data for 1： triclinic, space group P1^- with a = 5.7030（7）, b = 9.0625（11）, c = 16.5929（18） A, α = 91.808（7）°, β = 93.234（6）, γ = 99.216（7）°, C12H11N3SbCl5, Mr = 496.24, V = 844.44（17） A^3, Z = 2, Dc = 1.952 g/cm^3, μ（MoKα） = 2.419 mm^-1, F（000） = 480, the final R = 0.0496 and wR = 0.1382 for 3433 observed reflections （I 〉 2σ（I））. Crystal data for 2： monoclinic, space group P21/c with a = 7.8061（5）, b = 15.8127（9）, c = 12.2435（9） , β = 91.955（4）o, C24H22N6Hg2Cl8, Mr = 1079.26, V = 1510.40（17） 3, Z = 2, Dc = 2.373 g/cm3, μ（MoKα） = 10.889 mm-1, F（000） = 1008, the final R = 0.0293 and wR = 0.0562 for 2854 observed reflections （I 〉 2σ（I））. X-ray diffraction analysis reveals that the antimony（III） is five-coordinated, exhibiting a slightly distorted square-pyramidal coordination geometry; while in 2, a dimeric [Hg2Cl8]^4-anion consists of two trigonal bipyramids sharing two common edges. The organic cations and coordination anions are connected into a one-dimensional belt and a two-dimensional sheet through N-H···Cl hydrogen bonding interactions in compounds 1 and 2, respectively; both are further aggregated into 3D frameworks by strong π-π contacts.

Synthesis and anti-HBV activity of novel 5-substituted pyridin-2(1H)-one derivatives

Four novel 5-substituted pyridine-2(1H)-one derivatives were designed and synthesized by using addition-elimination reactions.The structures of these novelly synthesized compounds were verified by ~1H NMR,ESI-MS and single crystal X-ray diffraction.Furthermore,all four compounds(most notably compound 7a) were found to be highly efficient against hepatitis B virus (HBV) in cultured HepG2 2.2.15 cell,making them promising drug candidates for potential bioactive molecule against hepatitis B.

A 2D Wavy Parquet Architecture Based on the Biphenyl-3,3',4,4'-tetracarboxylic Acid and Bis(2-benzimidazole)alkanes Ligands

A double-T-shaped ligand （H4BPTC） and bis（2-benzimidazole）alkanes as the spacers have been firstly used to direct the assembly of a 2D coordination polymer with wavy parquet network topology, [Zn（BPTC）0.5（H2C2EIm）（H2O）]n （1, C24H18ZnN4O5, Mr = 507.79, H4BPTC = biphenyl-3,3＇,4,4＇-tetracarboxylic acid, H2C2EIm = 2,2＇-（1,2-ethanediyl）-bis（1H-benzi- midazole）, which was determined by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/n with a = 1.1844（5）, b = 1.4019（5）, c = 1.4026（5） nm, β = 108.359（5）°, V = 2.2104（15） nm3, Z = 4, Dc = 1.526 g/cm3, μ（MoKα） = 1.156 mm-1, F（000） = 1040, S = 1.038, the final R = 0.0427 and wR = 0.0793 for 3834 reflections with I 2σ（I）. The compound units are linked through BPTC ligands into a wavilness parquet 2D layer and further connected into a 3D framework via π-π packing interactions between the adjacent H2C2EIm ligands and weak N-H…O hydrogen bonding between uncoordinated carboxylate and the nitrogen atoms of H2C2EIm as well as the free water molecules.

Ga(ClO_4)_3-catalyzed Reaction of 1,2-Diamines and α-Bromoketones:Synthesis of 2-Substituted Quinoxalines

Ga（ClO4）3-catalyzed reaction of 1,2-aryldiamines and α-bromoketones to afford 2-substituted quinoxalines in good yields is described.The reaction proceeded via grinding process with 10%（molar fraction） catalyst under solvent-free conditions at room temperature.For unsymmetrical o-phenylenediamines bearing electron-withdrawing groups,regio-selective quinoxalines were obtained.

Synthesis of 2-Phenyl-10-substituted Hymenialdisine Derivatives

A series of novel 2-phenyl-10-substituted hymenialdisine derivatives was synthesized via the micro-wave-assisted Suzuki-Miyaura cross-coupling reactions of the 2-phenyl derivative of hymenialdisine and boronic acid, which enabled the successful introduction of electron-donating and electron-withdrawing groups to the 2-phenyl- hymenialdisine derivatives in good yields.

Syntheses of 2- or 6-Substituted Chromones and Chromone Ring-opening Reaction in Polyphosphoric Acid

In an attempt to find new antitumor agents,a novel class of chromone compounds with a benzimidazole or a benzoxazole ring in positions 2 or 6 were synthesized via condensation in polyphosphoric acid(PPA) by using chromone acids as the starting materials. During the preparation process,it was found that PPA could cleave the chromone ring to produce a ring-opening compound(6). The molar ratio of the chromone compound(5) to the ring-opening compound(6) varied with the change of reaction temperature and time. Based on MTT protocol,the antitumor activity of each of the compounds obtained was evaluated against three human cancer cell lines: KB(oral epidermal),A2780(ovary) and Bel7402(liver). The IC_ 50 varied from 54.7 μmol/L to more than 180 μmol/L.

Design, Synthesis and <i>in Vitro</i>Antibacterial Activity of 2-thiomethyl-benzimidazole Derivatives

A series of novel substituted benzimidazole (7a - n) derivatives were synthesized and characterized by 1H, 13C Nuclear Magnetic Resonance (NMR) spectra and High Resolution Mass Spectrometry (HRMS). The substitution was done in position -1 and -2 by appropriate groups. These compounds are obtained by N-alkylation reaction with thiomethyl-1H-benzimidazole intermediates (5a - g). Design of intermediates (5a - g) was made by condensation reaction between 2-methylbenzimidazole thiourunium salt (3) and functionalized halides (4) in the presence of sodium hydroxide (NaOH). Among the twenty-one compounds synthesized, ten were evaluated for their antimicrobial activity on three bacterial strains namely: Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853. Only E. coli ATTC 25922 was susceptible to the synthesized derivatives 5g, 7f and 7h with a significant antibacterial activity (CMI is between 250 and 500 μg/mL).

Some New Derivatives of 3H-benzo[b]Furo[3,2-f]- Benzimidazole with Expected Biological Activity

On the base of benzimidazole and benzofuran containing heterocyclic system, several derivatives with expected biological activity were synthesized. 2,3-diaminodibenzofuran was the primary substance. Adding various cyclic agents, 2-phenil was got, 2-（o-chlorophenil）, 2-（o-oxyphenil）, 2-chlorometyl- and 2-hydroximethyl-3H-benzo[b[furo（3,2-f] benzimidazoles. The aforementioned substances were characterized by IR and NMR spectroscopy.