Synthesis and Structure of 2-Isobutyl-6-(2',4'-dichlorophenyl)imidazo[2,1-b]-1,3,4-thiadiazole

The crystal structure of the title compound, 2-isobutyl-6-(2?4?dichlorophenyl)- imidazo[2,1-b]-1,3,4-thiadiazole (C14H13Cl2N3S, Mr = 326.23), has been synthesized by the treatment of 2-amino-5-isobutyl-1,3,4-thiadiazole with a-chloroaceto-2,4-dichlorophenone and determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 12.483(7), b = 8.420(4), c = 14.998(8) ? b = 105.770(10)? V = 1517.0(14) 3, Z = 4, Dc = 1.428 g/cm3, S = 0.902, m(MoKa) = 0.558 mm-1, F (000) = 672, R = 0.0579 and wR = 0.1186. The X-ray analytic results showed that all ring atoms in the imidazothiadiazole moiety are almost coplanar. The dihedral angel between the phenyl group and hetero-cycle is 16.8(0.2)?

Synthesis and anti-inflammatory activity of imidazo[1,2-a]pyrimidine derivatives

A series of imidazo[1,2-a]pyrimidine derivatives substituted adjacently with two aryls at positions 2 and 3 were designed and synthesized in order to improve their anti-inflammatory activities. Biological tests suggested that these compounds have antiinflammatory activities with COX-2 selectivity to some extent.

Synthesis of derivatives of imidazo[4,5-b]pyridine:Novel sulfur contained side chains for macrolide antibiotics

Two series of novel derivatives of imidazo[4,5-b]pyridine were synthesized. These compounds could be used as side chains of semisynthesised ketolide antibiotics. The side chains have free amine group which can attached to ketolide core. Macrolides with this kind of side chains will show obvious activities against erythromycin-resistant strains. The structure of the side chains was confirmed by ^1H, ^13C NMR, MS, HMBC spectra. 2007 Ping Sheng Lei. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

CuⅡ and CuⅠ Complexes of 1,1＇-（Pyridin-2-ylmethylene）-bis[3-（pyridin-2-yl）imidazo[1,5-a]pyridine]：in situ Generation of the Ligand via Acetic Acid-controlled Metal-ligand Reactions

Reaction of 3-（pyridin-2-yl）-imidazo[1,5-a]pyridine （HPIP）, CuCi2·2H20 and picolinaldehyde in the mixture of CHaCOOH and EtOH under solvothermal conditions gave complexes [LCuCI][CuECI3] （1） and [HLCuC1]E[CuCI2]2[CuCI3].2H20 （2） （L = 1,1＇-（pyridin-2- ylmethylene）bis[3-（pyridin-2-yl）imidazo[1,5-a]pyridine]） simultaneously. The ligand L was generated via in situ metal-ligand reaction between HPIP and picolinaldehyde. When CuCI2·2H20 was replaced by CuC1, the 2：1：1（HPIP：picolinaldehyde：CuCI） reaction afforded complex [CuaL2CI2][CuCI2]·2H20 （3） and the analogous 2：1：3 reaction generated compound [CuaL2][CuCI2]3 （4）. Complexes 1 and 2 are Cun/CuI mixed-valence compounds. Complexes 1-4 display four various structures. It is found that the formation of the L ligand is controlled by CH3COOH. This work reveals that the structures of complexes 1-4 could be rationally tuned via the inclusion of CH3COOH in the reaction systems, the proper selection of different starting materials and the dexterous adjustment of the ratio of the starting materials.

A New Cadmium(Ⅱ) Coordination Polymer Constructed by 2-(2-Chloro-6-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline and 1,2,3-Benzenecarboxylate: Synthesis, Structure and Luminescence

A new Cd（II） coordination polymer, namely, [Cd3（1,2,3-BTC）2（L）2]·2.25H2O （1, L = 2-（2-chloro-6-fluorophenyl）-1H-imidazo[4,5-A][1,10]phenanthroline and 1,2,3-BTC = 1,2,3-ben- zenetricarboxylate）, has been synthesized under hydrothermal conditions. The compound was characterized by single-crystal X-ray diffraction. It crystallizes in triclinic, space group Pī with α = 11.650（2）, b = 12.240（2）, c = 19.760（4） A, α = 72.01（3）, β = 77.11（3）, γ = 83.48（3）°, V = 2609.4（9） A3, Z = 2, C56H31Cd3Cl2F2N8O14.25, Mr = 1489.99, Dc = 1.896 g/cm3, F（000） = 1466, μ（MoKa） = 1.401 mm^-1, R = 0.0401 and wR = 0.1104. Compound 1 shows a 1D chain structure, and the neigh- boring 1D chains of 1 are joined together by π···π interactions to result in a 2D supramolecular layer. In addition, the luminescent property of 1 has been studied in the solid state at room temperature.

One-Pot Three-Component Synthesis of Imidazo[1,5-<i>a</i>]pyridines

A one-pot three component condensation synthesis of imidazo[1,5-a]pyridines using of various aromatic aldehydes and dipyridil ketone with ammonium acetate in the presence of Lithium chloride as catalyst in good yields under microwave irradiation has been described.

Synthesis and Pregnancy Terminating Activity of 2-Aryl imidazo [2,1-a] isoquinolines

Two 2-aryl imidazo [2,1-a] isoquinolines were synthesized and tested for pregnancy terminating activities. Both of them are new compounds and their structures were confirmed by IR, (HNMR)-H-1, MS and elemental analysis. They both showed high activities in NIH mice.

Synthesis and Evaluation of 8-[^(131)I]Iodo-substituted Imidazopyridine Derivative as Single Photon Emission Computed Tomography Tracer for Peripheral Benzodiazepine Receptors

A novel N-methyl, N-phenyl-[6-chloro-2-（4-chlorophenyl）-8-iodoimidazo[1, 2-a]- pyridine-3-yl]acetamide （compound Ⅴ） was synthesized, radiolabelled with 131I and evaluated in vitro. In vitro cell uptake studies showed that MDA-MB-231 cells yield four-fold higher specific uptake of [^131I]-compound Ⅵ than MCF-7 cells, corresponding to the increased expression of PBR in MDA-MB-231 cells. Blocking studies significantly reduced the MDA-MB-231 cells uptake of [^131I]-compound Ⅵ. It indicated that [^131I]-compound Ⅵ might be a potential SPECT radioligand for imaging of PBR.

Microwave-prompted rapid and efficient synthesis of 3-alkyl substituted imidazo[1,5-a]pyridines

Under regular heating and microwave irradiation, 3-alkyl substituted imidazo[1,5-a] pyridines were synthesized from 2,2＇- pyridil, di-2-pyridyl ketone and aliphatic aldehydes in the presence of ammonium acetate and acetic acid. Compared to the traditional heating condition, the reaction time under microwave irradiation was shorter and 3-alkyl imidazo[1,5-a]pyddines were given in higher yield.

Synthesis and Anticandidosic Activities of Some 3-Imidazo[1,2-a]Pyridinyl-1-Arylpropenone Derivatives

In this work, we show the synthesis of ten (10) new derivatives of 3-imidazo [1,2-a]pyridinyl-1-arylpropenone (10a - d). These new compounds were obtained by condensation of Claisen-Schmidt between derivatives of 2-substi- tuted-1H-imidazo[1,2-a]pyridine-3-carbaldehyde (3a - b and 7) and acetophenone derivatives (9a - e) in the presence of a base. The synthesized compounds were characterized by spectroscopic analyses 1H and 13C NMR. The antifungal activity of the ten (10) derivatives was determined on a resistant strain of Candida albicans by the microdilution method. The results showed that four (4) of them (10a, 10b, 10c and 10i) were active with minimum inhibitory concentrations (MICs) below 300 μmol/L. Of these four compounds, 10i was more potent than the others with a MIC of 41.98 μmol/L.

Synthesis and Evaluation of Antituberculosis Activity of Substituted 2,7-Dimethylimidazo [1,2-a]Pyridine-3-Carboxamide Derivatives

A series of substituted 2,7-dimethylimidazo[1,2-a]pyridine-3-carboxamides derivatives 5a-5m were synthesized through multi-step reactions. To achieve the synthesis of the desired compounds monobromo and dibromo substituted 2-amino-γ-picoline was reacted with ethyl 2-chloroacetoacetate. The crude ethyl ester subjected to hydrolysis in presence of lithium hydroxide to get 2a and 2b, with imidazo[1,2-a]pyri- dine-3-carboxylic acid to get 3a-3b, on treatment with substituted amines 4a-4g to get desired product 5a-5m in presence of EDCI and HOBt. The substituted imidazo[1,2-a]pyridine-3-carboxamides are characterized by FTIR, 1H-NMR, 13C-NMR and mass spectra. These newly synthesized compounds were tested in vitro for their antimycobacterial activity. The preliminary results of antituberculosis study showed that most of the synthesized compounds 5a-5m demonstrated moderate to good antituberculosis activity. Among the tested compounds 5b, 5d and 5e were found to be the most active with minimum inhibitory concentration (MIC) of 12.5 μg/mL against Mycobacterium tuberculosis (H37 RV strain) ATCC No-27294.

Synthesis and Crystal Structure of 7-Ethoxycarbonyl-2-methyl-6-methylthio-1H-imidazo[1,2-b]pyrazole

The title compound 7-ethoxycarbonyl-2-methyl-6-methylthio-lH-imidazo[1,2-b]- pyrazole （Mr = 239.29） was synthesized and structurally characterized by IR, ^1H NMR and single-crystal X-ray diffraction. It belongs to the triclinic system, space group P1, with a =8.0461（10）, b = 8.5534（11）, c = 9.5605（12）А,α= 64.804（2）,β= 74.231（2）, γ= 76.885（2）°, V = 568.27（12）А^3, Z = 2,Dc= 1.398 g/cm^3,μ= 0.274 nunl, F（000） - 252, the final R = 0.0454 and wR = 0.1261. A total of 3360 reflections were collected, of which 2466 were independent （R_int = 0.0138） and 2154 were observed with I〉2σ（I）.

Theoretical Investigation on the Stability and Reactivity of Imidazo [1,2-a] Pyridine N-Acylhydrazone Derivatives Using Density Functional Theory

The reactivity and stability of seventeen (17) imidazo [1,2-a]pyridine N-acylhydrazone derivatives were investigated using density functional theory at the B3LYP/6-31+ G (d, p) level. Analysis of the molecular electrostatic potential (MEP) and determination of the dual descriptor revealed that in most cases, the nitrogen atoms of the 6-πelectron conjugation, the oxygen, and the sulfur atom are nucleophilic site. Chemical reactivity of the compounds was assessed through analysis of frontier molecular orbitals (HOMO and LUMO), energy gap (Δℰ), chemical hardness (η), and the softness (S). Consequently, the compound 9e exhibited the lowest reactivity, least electron donating, and the highest stability. This comprehensive study offers valuable insights into the chemical behavior of these derivatives, crucial for further exploration and potential applications.

Visible Light-Induced C-5 Selective C-H Radical Borylation of Imidazo[1,2-a]pyridines with NHC-Boranes

A visible-light-induced C-5 selective C-H borylation of imidazo[1,2-a]pyridines with NHC-BH3 via Minisci-type radical borylation re-action has been developed for the first time.The present sustainable protocol provides a new family of regioselectively C5-borylated imidazopyridines that would otherwise be difficult to prepare.It is a supplement to site-selective borylation of azines(nitrogen-con-taining aromatic heterocycles)and the assembly of sp2 carbon-boron bond.

咪唑杂环与2-氨基苯并噻唑化合物交叉偶联产物探索合成

研究了咪唑杂环化合物与2-氨基苯并噻唑化合物在亚硝酸叔丁酯和醋酸钾条件下的交叉偶联反应,制备了系列苯并噻唑类咪唑杂环化合物,产率中等至优异。研究表明,苯环上带有较强吸电子基团的2-氨基苯并噻唑类化合物参与反应产率较低,甚至不发生反应。而在咪唑杂环并[2,1-b]噻唑杂环化合物底物中,噻唑环上具有取代芳基的底物表现较好,产率可达到90%以上。通过核磁共振氢谱、核磁共振碳谱、红外光谱、高效液质联用仪等分析方法对合成产物的结构进行了表征,证明了合成方法的可靠性。

Crystal Structure of Adduct 2-Phenyl-imidazo[4,5-f] 1,10-phenanthroline Methanol

absractThe structure of the title adduct comprises a phenanthroline derivative 2 phenyl imidazo[4,5 f ] 1,10 phenanthroline and a methanol. The composition of the crystalline adduct was cha^racterized as C 19 H 12 N 4·CH 3OH. It belongs to orthorhombic system, space group Pna 2 1 with a =1 3693(4) nm, b = 2 2988(7) nm, c =0 51338(15) nm, V =1 6160(8) nm 3, Z =4, and final R 1=0 0423, wR 2=0 1012. Crystal structure shows that all the 19 carbon atoms and 4 nitrogen atoms are coplanar. The bond length data indicated that a very extensive conjugation system was formed. This conjugation makes the compound being a potentially excellent energy transformer used for luminescent materials.

Off-on-off luminescent switching of a dye containing imidazo[4,5-f][1,10]phenanthroline

A new acid-base fluorescent switch containing both imidazo[4,5-f][1,10]-phenanthroline and triphenylamine groups has been synthesized.Its fluorescence emissions and absorptions can be reversibiy changed through protonation/deprotonation of imidazole and amine moiety by controlling the intramolecular charge transfer（ICT） process,leading to off-on-off fluorescent molecular switching.

可见光促进三组分合成C3-芳甲基取代的咪唑并[1,2-a]吡啶衍生物

C3-芳甲基取代的咪唑并[1,2-a]吡啶衍生物在材料及药物化学领域有着广泛应用。基于自由基对亚胺C=N键的插入串联环化策略,以2-氨基吡啶衍生物、芳基甲醛为原料、芳基溴乙炔为自由基源,在可见光促进和路易斯酸协同作用下,通过三组分串联反应,以70%~78%的产率实现了C3-芳甲基取代的咪唑并[1,2-a]吡啶衍生物的构建。目标产物结构经^(1)H NMR、^(13)C NMR和HR-MS确证。本方法无需额外添加光催化剂,操作简便、反应条件温和,具有较好的底物适用性和官能团耐受性,并且可以应用于唑吡坦的一步合成。

2,3-Diaryl-3H-imidazo[4,5-b]pyridine derivatives as potential anticancer and anti-inflammatory agents

In this study we examined the suitability of the 3H-imidazo[4,5-b]pyridine ring system in developing novel anticancer and anti-inflammatory agents incorporating a diaryl pharmacophore. Eight 2,3-diaryl-3H-imidazo[4,5-b]pyridine derivatives retrieved from our in-house database were evaluated for their cytotoxic activity against nine cancer cell lines. The results indicated that the compounds showed moderate cytotoxic activity against MCF-7, MDA-MB-468, K562 and SaOS2 cells, with K562 being the most sensitive among the four cancer cell lines. The eight 2,3-diaryl-3H-imidazo[4,5-b]pyridine derivatives were also evaluated for their COX-1 and COX-2 inhibitory activity in vitro. The results showed that compound 3f exhibited 2-fold selectivity with IC_(50) values of 9.2 and 21.8 mmol/L against COX-2 and COX-1, respectively. Molecular docking studies on the most active compound 3f revealed a binding mode similar to that of celecoxib in the active site of the COX-2 enzyme.