Studies on the Synthesis of Pyridine Analogs of the Natural Product3,5,4'-Trimethoxystilbene

Five pyridine analogs of the natural product, 3, 5, 4'-trimethoxystilbene, were synthesized. The final compounds were characterized by 1H-NMR.

Synthesis, Crystal Structure and Property of a Series of Supramolecular Polymers Based on Novel 3,5-Dimethyl- 2,6-bis(3-(pyrid-2-yl)-1,2,4-triazolyl)pyridine Ligand

Solvothermal reactions of 3,5-dimethyl-2,6-bis（3-（pyrid-2-yl）-1,2,4-triazolyl） pyridine （L）, 1,4-benzendicarboxylic acid （H2bdc）, and transitional metal cations of M11 （M = Mn, Co, Cd） in the presence of oxalic acid （H2ox） afford three novel supramolecular polymers （CPs）, namely, {[M2（ox）（L）2][bdc][M2（Hox）2（OH）（H2O）4]·3H2O}n （M = Mn for 1, Co for 2, Cd for 3）. Single-crystal X-ray diffraction analysis reveals that complexes 1-3 are isostructural and the 3D supramolecular structure was connected through non-covalent interactions. With the help of H2ox, the L ligands cheated with center atoms forming a butterfly [M2（ox）（L）2]2＋ building block. The bdc2- ligand linked with the unprecedented [M2（Hox）2（OH）2（H2O）4] units through strong O-H...O hydrogen bonds forming a zigzag chain, which are further connected through π-π interactions between L and bdc2- ligands to form a 3D supramolecular structure. Moreover, elemental analyses, IR, thermogravimetric, PXRD and luminescence have been investigated.

A New Zn(Ⅱ) Coordination Polymer Constructed from 4-(1H-pyrazol-3-yl)pyridine as Fluorescent Sensor for Fe^(3+)

A new Zn(Ⅱ) coordination polymer, [Zn(4-PP)(1,4-BDC)?(H_2O)]_n(1, 4-PP = 4-(1 H-pyrazol-3-yl)pyridine, 1,4-H_2BDC = 1,4-benzenedicarboxylic acid), has been synthesized and structurally characterized by single-crystal X-ray diffraction as well as elemental analysis, IR spectra, XRPD and TG. Structural analysis reveals that Zn(Ⅱ) ions are bridged by COO-from 1,4-BDC^(2-)to form a binuclear structure as the second building units(SBUs). Zn_2 clusters can be clarified as 4-connected nodes, so the framework of 1 can be considered as a 2 D(44?62)-sql sheet. Fluorescence measurements show that 1 has highly selective and sensitive detection of Fe^(3+) in water medium.

Synthesis,Crystal Structure,DFT Studies and Biological Activity of a Novel Schiff Base Containing Triazolo[4,3-a]pyridine Moiety

The novel Schiff base（E）-8-chloro-NA-（4-（dimethylamino）benzylidene）-[1,2,4]triazolo[4,3-a]pyridine-3-carbohydrazide was synthesized and characterized by ^1H NMR,MS,elemental analysis and X-ray diffraction.The compound crystallizes in the monoclinic space group P2_1/c with a = 7.091（2）,b = 10.750（3）,c = 21.380（6） A,β = 96.299（6）°,V = 1619.7（8） A^3,Z = 4 and R = 0.0351.Theoretical calculation of the title compound was carried out with the B3LYP/6-31 G basis set.The frontier orbital energy and atomic net charges were discussed.It is found that the experimental data show good agreement with the calculated values.And the compound exhibits good antifungal activity against Stemphylium lycopersici（Enjoji） Yamamoto.

Synthesis,Crystal Structure and Antifungal Activity of 8-Chloro-3-((4-chlorobenzyl)-thio)[1,2,4]triazolo[4,3-a]pyridine

The title compound 8-chloro-3-（（4-chlorobenzyl）thio）-[1,2,4]triazolo[4,3-a]pyridine was prepared from 1-chloro-4-（chloromethyl）benzene and 8-chloro-[1,2,4]triazolo[4,3-a]pyridine-3（2H）-thione in the presence of Na OH, and its structure was determined by X-ray diffraction analysis. The crystal is of triclinic system, space group P1 with a = 6.8264（6）, b = 7.5890（4）, c = 13.0960（7） A, α = 93.447（4）, β = 98.772（6）, γ = 92.615（6）o, V = 668.26（8） A3, Z = 2, the final R = 0.035 and wR = 0.09 for 2259 observed reflections with I 〉 2σ（I）. The preliminary biological test showed that the title compound has activities against Stemphylium lycopersici（Enjoji） Yamamoto, Fusarium oxysporum. sp. cucumebrium, and Botrytis cinerea with inhibitory to be 51.19%, 62.02% and 15.56%, respectively.

Synthesis and Crystal Structure of a Three-dimensional Mn(Ⅱ) Coordination Polymer with 3-(Pyrazin-2-yloxy)-pyridine and Azide Anion as Mixed Bridge Ligand

A three-dimensional coordination polymer [Mn2（μ1.3-N3）4（μ-PP）2]n （PP = 3-（pyrazin-2-yloxy）-pyridine） has been synthesized with 3-（pyrazin-2-yloxy）-pyridine and azide anion as mixed bridge ligand, and its crystal structure was determined by X-ray crystallography. The crystal data： triclinic system, space group P1, with a = 6.794（4）, b = 9.885（6）, c = 9.947（6） A, α = 64.170（6）, β= 84.190（8）, γ= 85.319（8）°, V = 597.7（6）A^3, Z = 1, C18H14Mn2N18O2, Mr = 624.35, Dc = 1.735 g/cm^3, F（000） = 314 and μ = 1.117 mm^-1. In the crystal, the azide anion acts as a bridge ligand and makes adjacent Mn（Ⅱ） ions connect into a two-dimensional sheet on the ab plane, then 3-（pyrazin-2-yloxy）-pyridine serves as a bidentate bridge ligand to connect neighboring sheets along

Synthesis,Crystal Structure,and Magnetic Property of One 3D Nickel Coordination Polymer Based on 2-Hydroxy-5-(3',5'-terephthalic acid)Pyridine and 1,4-Bis(1-imdazoly)benzene

One novel nickel coordination polymer, {[Ni（OTP）（bib）1.5（H2O）]·2H2O}n（1, H2 OTP = 2-hydroxy-5-（3＇,5＇-terephthalic acid） pyridine, bib = 1,4-bis（1-imdazoly）benzene）, has been synthesized and characterized by elemental analysis（EA）, IR, powder X-ray diffraction（PXRD）, and thermogravimetric（TG） analyses. The crystal of 1 crystallizes in monoclinic, space group P21/n with a = 12.2860（5）, b = 13.8246（6）, c = 19.0140（8） A, β = 104.3870（1）°, V = 3128.2（2） A3, Z = 4, C32H28N7 Ni O8, Mr = 697.32, Dc = 1.481 g/cm^3, F（000） = 1444 and μ（Mo Kα） = 0.684 mm-1. The final R = 0.0704 and w R = 0.1764 for 5485 observed reflections with I 2σ（I） and R = 0.1087 and wR = 0.2010 for all data. Topology analysis reveals that complex 1 is a 3D 2-fold interpenetrated {4^4·6^6}-nov net based on the 1D [Ni（OTP）]n chain and the 2D [Ni2（bib）3]n sql sheet. And the variable-temperature magnetic susceptibility measurements exhibit weak antiferromagnetic coupling interaction.

The First Example of a Supramolecular Structure Containing [2-(1H-Pyrazol-3-yl)-pyridine] Complex and both α-and β-Octamolybdates

The title compound, [Ni（C8N3H7）3]4[Mo8O26]2·6H2O 1, has been synthesized from the reaction of 2-（1H-pyrazol-3-yl）-pyridine （L） with （NH4）2MoO4·2H2O and NiCl2·6H2O. Elemental analysis, IR, UV spectra and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure of the compound. Crystal data： C96H96Mo16N36Ni4O58, Mr = 4451.97, monoclinic system, space group P21/n, a = 20.846（5）, b = 14.825（5）, c = 23.122（5） A ,β= 91.594（5）°, V = 7143（3）A^3, Z = 2, F（000） = 4344, Dc = 2.070 g/cm^3,μ = 1.968 mm^-1, R = 0.0452 and wR = 0.1056 for 17102 independent reflections （Rint = 0.0442） and 11074 observed reflections （I 〉 2σ（I））. Structural analysis indicates that two kinds of octamolybdates （[α-Mo8026]^4- and [β-Mo8026]^4-） co-exist in the compound. This is the first example of a supramolecular structure containing L complex as well as both α- and β-octamolybdate clusters.

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.

New and Facile Synthesis of Substituted Pyrrole, Pyridine, Pyrazolo[4,3-b] Pyridine, Pyrano[3,2-c] Quinoline, Napthopyran, Naphthodipyran and Coumarin Derivatives

Several new pyrazolo[4,3-b] pyridines 7a, b were prepared by reacting arylidenemalononitriles 1a, c or 1i, j with 4-nitrosoantipyrine 4. Reacting 1a, b, d with 4-azidomethylcarbonylantipyrine 8 give 2-aminopyrrole 14. Pyrano[3,2-c] quinolines 20a, b and 23 were obtained by reacting 4-hydroxyquinoline 15 with 1g, h, 2b respectively. Reaction of 1 with naphthalenediols 24, 27 and 29 yield naphthodipyrans 26a, b, 28a, b and 30a。

Synthesis and Structure of 3-Trichlorostannylpropionate Complexes with Dibutylsulfoxide and Pyridine Oxide

A series of 3-trichlorostannylpropionate complexes with dibutylsulfoxide and pyridine oxide were synthesized by transesterification reaction and characterized by means of elemental analysis, IR, NMR(H-1,C-13) and X-ray single crystal diffraction.

Coherent-Synchronized Oxidation of Pyridine with Nitrous Oxide to 2,2- and 2,3-Dipyridil

Synthesis of pyridine bases by way of relatively simple transformations with use of cheaper and available raw, is an actual problem. In this aspect the method in which the reactions of hydro-carbons oxidation are induced by nitrous oxide, is of scientific and practical interest. In the present work, the authors report the results of the experiments coherent-synchronized oxidation of pyridine with nitrous oxide to 2,2- and 2,3-dipyridyle.

Synthesis, Reactions and Characterization of 1,1’-(1,4-Phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(ethan-1-one)

Reaction of 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile) (1) with methyl iodide afforded the 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-(methylthio)nicotinonitrile) (2). The reaction of 2 with hydrazine hydrate followed by diazotization reaction af-forded the 1,1’-(1,4-phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(e-than-1-one) (3) and 1,1’-(1,4-phenylenebis(3-(chlorodiazenyl)-6-methyl-1H-pyrazolo[3,4-b]-pyridine-4,5-diyl))bis(ethan-1-one) (4) respectively. On the other hand, reaction of 4 with malononitrile, 2-cyanoethanethioamide, ethyl acetoacetate, acetyl acetone, ethyl benzoylacetate, diethylmalonate, ethyl cyanoacetate and phenacylbromide aiming to build up pyrazolotriazine or pyrazole ring on the ring system of 4. Structures of all newly synthesized heterocyclic compounds in the present study were confirmed by considering the data of IR, 1H NMR, mass spectra as well as that of elemental analyses.

Heterosynthesis Using Nitriles: Novel Pyrrolo[2,3-<i>b</i>]pyridines

2-Amino-4-benzoyl-1-arylpyrrole-3-carbonitriles react with arylidene malonodinitriles, β-ketoesters and β- diketones to afford pyrrolo[2,3-b]pyridine derivatives.

A New Diiminopyridyl Cobalt Complex [CoCl_2L](L=2,6-Bis(N,N'-bis(2,6-diisopropyl-4-(2,3-dimethyoxylbenzoylamide)phenylimino))pyridine)

The reaction of CoCl2·6H2O with 2,6-bis（N,N＇-bis（2,6-diisopropyl-4-（2,3-dimethy-oxyl-benzoylamide）phenylimino））pyridine（L） afforded the complex [CoCl2L],which was fully characterized by elemental analysis,UV-vis,IR spectroscopy,fluorescence,and X-ray diffraction analysis.The compound is of triclinic system,space group P1 with a = 13.058（3）,b = 13.798（3）,c = 16.695（3） ,α = 98.191（3）,β = 102.792（3）,γ = 101.820（3）°,V = 2815.0（9） 3,Z = 2,F（000） = 1122,μ = 0.45 mm-1,R = 0.061 and wR = 0.1349 for 9842 observed reflections（Ⅰ 〉 2σ（Ⅰ））.The Co（Ⅱ） center adopts a distorted square-pyramidal coordination geometry.The extended structure shows a one-dimensional zigzag double chain linked by hydrogen bonds and π-π stacking interactions.

Broad-Spectrum Antiproliferative Activity of Diarylureas and Diarylamides Possessing Pyrrolo[3,2-c]Pyridine Scaffold

A series of diarylureas and diarylamides possessing pyrrolo[3,2-c]pyridine scaffold was designed and synthesized. Their in vitro antiproliferative activities were tested against a panel of 49 cell lines of eight different cancer types at the NCI and compared with Sorafenib as a reference compound. Most of the compounds showed strong and broad-spectrum antiproliferative activities with superior potencies to Sorafenib. Compounds 8a, 9d and 9f showed lethal effect with mean %inhibition more than 100% over the 49 tested cell lines. In addition, the mean %inhibition results of compounds 8d, 8e, 9e, 9g and 9h were more than 80%. And most of the IC50 values of the target compounds were in submicromolar scale. Compounds 8a, 9b and 9e demonstrated high selectivity towards cancer cell lines compared with NIH3T3 fibroblasts.

Green Chemistry Approach to Fast and Highly Efficient One-Pot Synthesis of Bis-Isoxazolyl-1,2,5,6-Tetrahydro Pyridine-3-Carboxylates

The synthesis of the bis-isoxazolyl-1,2,5,6-tetrahydro pyridine-3-carboxylates is achieved in high yield without the production of toxic waste products by using room temperature ionic liquid (RTILs) triethyl ammonium acetate (TEAA). The RTIL TEAA played the dual role of efficient green solvent as well as recyclable catalyst.

Synthesis, Spectral and Electrochemical Studies of Complex of Uranium(IV) with Pyridine-3-Carboxylic Acid

The investigation of complexation of uranium with biological active ligands is vital for understanding uranium speciation in biosystems. A number of studies have been undertaken for investigating the complexation of uranium in its (VI) oxidation states but similar investigations pertaining to the interaction of uranium, in lower oxidation states, with biological ligands is scarce. The aim of the work is to bridge this gap and studies have been carried out to determine the coordination pattern of pyridine-3-carboxylic acid with uranium(IV). Semi-micro analysis, spectro-analytical techniques, magnetic susceptibility and cyclic voltammetry have been employed for the characterization of the synthesized complex.

Theoretical Study on the Reaction Mechanism of 2-Methoxybenzaldehyde,4-Bromo-indanone,Malononitrile and Ammonium Acetate One-pot to Form 6-(2-Methoxyphenyl)-2-amino-6-bromo-5H-indeno[1,2-b]pyridine-3-carbonitrile

The reaction mechanism of 2-methoxybenzaldehyde, 4-bromo-indanone, malononitrile and ammonium acetate one-pot to form 6-（2-methoxyphenyl）-2-amino-6-bromo-5 Hindeno[1,2-b]pyridine-3-carbonitrile was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Reaction pathways were investigated in this study. The result indicates that the reaction Re→ TSB1→IMB1→ TSB2→ IMB2→TSB3→IMB3→TSB4→IMB4→TSB5→IMB5→TSB6→IMB6→TSB7→IMB7→ TSB8→IMB8→TSB9→IMB9→P2 is the main pathway, the activation energy of which is the lowest. The dominant product predicted theoretically is in agreement with the experiment results.

1D Lanthanide Coordination Polymers Based on 3-(Pyridin-4-yl)benzoic Acid: Syntheses, Structures and Luminescent Properties

ABSTRACT Four novel 1D lanthanide coordination polymers with formula [Ln（3,4-pybz）3（HzO）2. H2O]n （Ln = 1 Sm; 2 Eu; 3 Tb; 4 Dy, 3,4-Hpybz = 3-（pyridin-4-yl）benzoic acid） have been synthesized by hydrothermal reactions of lanthanide oxide and 3-（pyridine-4-yl） benzoic acid. Single-crystal X-ray diffraction shows that the four compounds are isostructural. They all crystallize in a monoelinic system, space group P1^-. They have a doubly carboxylate-bridged infinite-chain structure with alternating Ln-（carboxylate）2-Ln linkages and one chelating carboxylate group on each metal center. The Ln ion also combines to two water molecules to form an eight-coordinate square antiprismatic geometry. The pyridine nitrogen atoms of the ligand do not coordinate to the metal centers but direct the formation of a 3D network through hydrogen bonding with coordinated water molecules. The photoluminescent properties of 2 and 3 have been also studied.