Synthesis, spectroscopic properties and crystal structure determination of 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole derivatives

Substituted 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole derivatives 2, 3 and 6 were synthesized. 2-(2-Pyridin-4-yl-vinyl)-1H-benzimidazole 2 and 6-methyl-2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole 3 were prepared by condensation reaction from 3-pyridin-4-yl-acrylic acid and corresponding 1,2-phenylenediamines in polyphosporic acid (PPA). 2,7,11-b-Triaza-benzo[c]fluorene 4 was prepared by photochemical dehydrocyclization reaction of ethanolic solution of 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole 2. 2-(2-Pyridin-4-yl-vinyl)-3H-benzimidazole-6-carbonitrile 6 was prepared by condensation reaction from 3-pyridin-4-yl-propenal and 4-cyano-1,2-phenylenediamine using p-benzoquinone as oxidants. The structure of novel benzimidazole derivatives has been studied by ¹H and ¹³C NMR, IR, MS, UV/Vis and fluorescence spectroscopy. The structure of 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole 2 was confirmed by X-ray single crystal structure analysis. The conformation of the molecule is E in regard to substituents position around vinyl double C=C bond. The non-planar molecules are mutually connected via the N–H···N and C–H···N type of intermolecular hydrogen bonds into infinite chains spreading along y axis.     

1,4-Diacyl-3-acylamino-5-aryl-4,5-dihydro-1H-1,2,4-triazoles: Ring closure products of aromatic carbaldehyde (diaminomethylene) hydrazones with acylating agents

Summary Treatment of aromatic carbaldehyde (diaminomethylene)hydrazones1 with hot acetic anhydride or benzoyl chloride affords 1,4-diacyl-3-acylamino-5-aryl-4,5-dihydro-1H-1,2,4-triazoles2. In contrast, a new type of 0,N-acetal with an 1,2,4-triazole substructure (3) is obtained from 4-pyridine-carbaldehyde (diaminomethylene)hydrazone (li) by using a similar reaction procedure. The structures of all novel compounds were confirmed by spectroscopic data (¹H and¹³C NMR, MS, IR); some representative compounds were also studied by X-ray analysis.Dedicated to Professor Dr.S. Makleit on the occasion of his 65^th birthday.     

m -Terphenyl derivative of titanium(III): Cp2TiR (Cp=C5H5; R =2,6-(4-MeC6H4)2C6H3)

The title compound, Cp₂TiR (Cp=C₅H₅; R=2,6-(4-MeC₆H₄)₂C₆H₃), 1, was prepared by reaction of RLi with [Cp₂TiCl]₂. Compound 1 was characterized by elemental analysis, EPR, and single crystal X-ray crystallography. The title compound crystallizes in the monoclinic space group C2/c with the following unit cell dimensions: a=11.1466(7) Å, b=16.4429(11) Å, c=13.0786(8) Å; b=106.2040(10)^°;V=2301.9(3) ų. The EPR spectrum of 1 displays two signals, a high field signal at g=1.979 and a lower field signal at g=1.959. Significantly, 1 is a sterically encumbered m-terphenyl-stabilized trivalent titanocene paramagnetic complex and may be a practical one-electron reducing reagent.     

N-(2-氧乙酸-3-甲氧基)苄叉二胺合锌(Ⅱ)配合物的合成、晶体结构及光学性质研究

本文通过修饰邻香草醛芳环上羟基的方法,得到两种Schiff碱配体:N,N′-二(2-氧乙酸-3-甲氧基)苄叉乙二胺(H2L1)和N,N′-二(2-氧乙酸-3-甲氧基)苄叉1,3-丙二胺(H2L2),利用水热合成方法以新合成的配体为基点设计合成了2个新的六配位Schiff碱锌(Ⅱ)配合物[Zn(L1)]·7H2O(1)和[Zn(L2)]·7H2O(2),通过元素分析、红外光谱和核磁共振光谱等测试手段对配合物进行了表征,并用X射线单晶衍射测得Zn(Ⅱ)配合物的晶体结构。X射线晶体学研究表明两种配合物晶体结构中都包含多个溶剂水分子,配合物1是以Zn(Ⅱ)为中心扭曲的三方棱柱构型,配合物2是以Zn(Ⅱ)为中心扭曲的八面体构型。初步研究了两种配合物的固体发光性,结果表明这两种配合物具有良好的光致发光的性能,有望在光学材料方面得到应用。     

两个三维柱层式单一手性配位化合物:合成、结构和性质（英文）

在溶剂热合成条件下得到2个单一手性配位聚合物,即[Cd3((R)-CIA)2(bipy)2.5(H2O)2]·xGuest(1)和[Zn3((R)-CIA)(bmib)2(H2O)2 Cl]·H2O·xGuest(2)((R)-H3CIA=(R)-5-(1-羧基乙氧基)间苯二甲酸,bipy=4,4′-联吡啶,bmib=1,4-双(2-甲基-1H-咪唑-1-基)苯)。X射线单晶结构分析揭示配合物1和2都是柱层式结构的三维框架。从拓扑分析的角度看,配位物1具有(3,3,3,6,6)-连接的网络,拓扑符号为(4.5^2)2(4.8^2)2(42.6^8.8^3.10^2)(4^2.6^8.8^3.9^2)(5.8.9)2,而配合物2是(3,4,4)-连接的网络,拓扑符号为(6·7^2)2(6·7^5)2(6^2·7^4)。此外,对上述配合物的热稳定性、圆二色谱和荧光性质也做了研究。     

N-(2-氧乙酸-3-甲氧基)苄叉二胺合锌(Ⅱ)配合物的合成、晶体结构及光学性质研究

本文通过修饰邻香草醛芳环上羟基的方法,得到两种Schiff碱配体:N,N'-二(2-氧乙酸-3-甲氧基)苄叉乙二胺(H₂L¹)和N,N′-二(2-氧乙酸-3-甲氧基)苄叉1,3-丙二胺(H₂L₂),利用水热合成方法以新合成的配体为基点设计合成了2个新的六配位Schiff碱锌(Ⅱ)配合物[Zn(L¹)]·7H₂O(1)和[Zn(L²)]·7H₂O(2),通过元素分析、红外光谱和核磁共振光谱等测试手段对配合物进行了表征,并用X射线单晶衍射测得Zn(Ⅱ)配合物的晶体结构。X射线晶体学研究表明两种配合物晶体结构中都包含多个溶剂水分子,配合物1是以Zn(Ⅱ)为中心扭曲的三方棱柱构型,配合物2构型是以Zn(Ⅱ)为中心扭曲的八面体构型。初步研究了两种配合物的固体发光性,结果表明这两种配合物具有良好的光致发光的性能,有望在光学材料方面得到应用。     

Synthesis and antiemetic activity of 1,2,3,9-tetrahydro-9-methyl-3-(4-substituted-piperazin-1-ylmethyl)-4H-carbazol-4-one derivatives

5-HT₃ receptor antagonists, such as Ondansetron, are used for anti-emesis after chemotherapy, radiotherapy and operations. Some Ondansetron analogs possessing piperazine ring as side chains were synthesized in our lab. Thus, one of the two carbonyl groups of starting material 1,3-cyclohexandione (1) was condensed with phenylhydrazine hydrochloride to form monophenylhydrazone (2). 1,2,3,9-Tetrahydro-4H-carbazol-4-one (3) was prepared from 2 via cyclization and rearranged in the presence of ZnCl₂. Through a methylation reaction, compound 3 was converted to 1,2,3,9-tetrahydro-9-methyl-4H-carbazol-4-one (4). 3-Dimethylaminomethyl substituted compound (5) was synthesized from 4 by a Mannich reaction in glacial acetic acid. Nine novel 1,2,3,9-tetrahydro-9-methyl-3-(4-substituted-piperazin-1-ylmethyl)-4H-carbazol-4-one derivatives (6a–6i) were synthesized through nucleophilic substitution reaction of 5 with piperazines. The structures of all the target compounds were determined by elemental analysis, IR, MS, ¹H NMR and ¹³C NMR spectra. The results of preliminary pharmacological test show that part of the novel compounds have antiemetic activity comparable to that of the control Ondansetron. __________ Translated from Chinese Journal of Organic Chemistry, 2008, 28(2) (in Chinese)     

Crystal structures,selective fluorescent sensing and photocatalytic properties of cobalt(II) and copper(II) coordination architectures with 2,4,5-tri(4-pyridyl)-imidazole

Abstract

Solvothermal reaction of M^II (M?=?Co, Cu) ions with 2,4,5-tri(4-pyridyl)-imidazole (Htpim) gave two MOFs, [Co_1.5(tpim)(FA)₂(H₂O)]_n (1) and [Cu₂(Htpim)(tpim)(FA)(NO₃)₂(DMF)]_n (2) (HFA?=?formic acid, DMF?=?N,N-dimethylformamide). Single-crystal X-ray diffraction analyses indicated that 1 exhibits a 3D {4³.4¹²} topology framework assembled by hexanuclear [Co₆(FA)₈(H₂O)₄] units and tpim ligands, while 2 presents a 2-D double layer {4.6²}₂{4².6⁴.8².10²}{6².8} network. Hereinto, an inorganic acid was not only used to adjust the pH value of reaction system but also to act as an oxidizing agent to participate in in situ organic reactions. Moreover, 1 displays high sensitivity in the detection of nitrobenzene as a fluorescent sensor and exhibits a relatively good photocatalytic activity toward the degradation of rhodamine B in aqueous solution under UV irradiation.     

Über die Darstellung von substituierten 3,4-Dihydro-2(1H)-pyrimidin-iminen und 2-Aminopyrimidinen aus Guanidin und α,β-ungesättigten Ketonen

Guanidine reacts with the 2-alken-1-ones4 a-f and5 to give the unstable dihydropyrimidinimines (or-amines respectively)8 a-f (I, II or III respectively) and the hexahydroquinazolinimine (-amine)9 (I, II or III);8 a-f lose H₂, partly in the course of the reaction, partly during recrystallization to yield the 2-pyrimidinamines10 a-c, e, f, and the 4-methyl-5,6,7,8-tetrahydro-2-quinazolinamine11. With picric acid the unstable compounds8 d, f and9, resp. are converted into the stable 2-amino-3,4-dihydro-1H-2-pyrimidinylium picrates12 d and into the 2-amino-4-methyl-3,5,6,7,8,8 a-hexahydro-1H-2-quinazolinium picrate (13 resp.14, 15)¹⁸, whereas8 e reacts with HCl to give the chloride12 e. The structures of12 d-f follow from their NMR-spectra, and of10 a-c, e, f and11 by alternative syntheses by known methods^12–17 (e.g. from -diketones and guanidine). The reaction of8 d-f and9 to10 d-f and11 respectively is compared with previously described dehydrogenation and disproportionation reactions, especially of 3,4-dihydro-2(1H)-pyrimidinones (6 d ⁴,23 ²⁰) and-thiones (30 ¹) of similar structure and formulated as a base-catalysed elimination of H₂.

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HerrnA. Fuchsgruber danken wir für die Aufnahme und Hilfe bei der Interpretation der NMR-Spektren.     

Experimental and theoretical studies on the functionalization reactions of 4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carboxylic acid and-acid chloride with various aminophenols

The 1H-pyrazole-3-carboxylic acid 1 was converted via reactions of its acid chloride 2 with various aminophenol derivatives 3a--d into the corresponding N-(hydroxyphenyl)-1H-pyrazole-3-carboxamides 4a--d, respectively, in good yields (34–53%). The reactions of 1 or 2 with 3 in benzene or toluene for 5–7 h with no catalytic amounts of base lead to the formation of the products 4. The structures of all new synthesized compounds were established by the ¹³C NMR,¹H NMR, IR, masss spectroscopic data and elemental analyses. The reaction mechanism of 2 with 3 was studied by means of the RHF/3-21G and RHF/6-31G method.     

A 2-D CdI2 coordination network with 7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylate: synthesis,crystal structure,and luminescent properties

The in situ reaction of Cd(ClO₄)₂·6H₂O with 7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylic anhydride in the presence of lithium hydroxide affords a 2-D Cd^II coordination polymer, [Cd(L)(H₂O)]_∞ (1) (L?=?7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylate), which exhibits an unusual (3,6)-connected (4⁶.6⁶.8³)(4³)₂ CdI₂-type topology. The luminescent and thermal properties of 1 were investigated.     

二茂铁四唑和二茂铁甲醛缩3-取代丙二醇衍生物的合成

以甲酰基二茂铁6为原料, 通过与NH₄OH•HCl的缩合反应得到二茂铁肟7, 再经脱水剂脱水得到二茂铁腈8, 最后在(n-C₄H₉)₃SnCl的作用下与NaN₃反应生成新化合物二茂铁四唑(9). 以甲酰基二茂铁为原料, 在对甲苯磺酸(PTSA)的催化作用下与原甲酸三甲酯反应生成二甲基二茂铁缩醛(10), 然后与(R)-(－)-3-氯-1,2-丙二醇反应得到新的二茂铁缩醛衍生物12, 12再与NaN₃发生取代反应得到新的二茂铁缩醛衍生物13. 而新的二茂铁缩醛衍生物15的合成则是先由(R)-(－)-3-氯-1,2-丙二醇与CH₃OH在NaOH的作用下生成(R)-(－)-1-甲氧基-2,3-丙二醇(14), 再由14与二甲基二茂铁缩醛(10)反应得到的. 所合成的新化合物都用MS, ¹H NMR和IR谱确证了它们的结构.     

Untersuchungen von Reaktionsmechanismen durch Isotopenmarkierung,VII. Zum Mechanismus der Ringverengung von 2,2-Dichlor-6-methyl-4H-1-thiochroman-3,4-dion

It is shown by use of¹⁴C-labeling that the ring contraction reaction of 2,2-dichloro-6-methyl-4H-1-thiochroman-3,4-dione (1) leads to elimination of C-2 as CO₂. Formation of the 5-methyl-2,3-dihydrobenzo[b]thiophen-2,3-dione (2) is suggested to proceed via hydrolytic opening of the thiolactone-binding in1. recyclisation and subsequent oxidation by unreacted1.

Herrn emer. Univ. Prof. Dr.E. Ziegler zur Vollendung seines 70. Lebensjahres mit besten Wünschen gewidmet.     

Preparation and Characterization of Some Novel Diphenylphosphine Hydrazones and Semicarbazones and Their Metal Complex Derivatives

Interaction of hydrazones and semicarbazones derivatives I _{a ? t} with diphenylchlorophosphine II , gave new compounds III _a?t , and their complexation ability towards various divalent metal acetates Mn(OAc)₂. 4H₂O, Co(OAc)₂. 4H₂O, Ni(OAc)₂. 4H₂O, and Cu(OAc)₂. H₂O, in organic solvents are described. The metal/ phosphorsemi-carbazones ratios are measured and the results discussed. All these complexes are insoluble in organic solvents and in water. The structures of the isolated products were proposed on the basis of microanalyical data, TGA, IR, (UV/ VIS), (MS), and ¹H, ¹³C, and ³¹P-NMR spectroscopic analyses and magnetic susceptibility. The proposed structure of the complexes is based on a 1: 2 metal: ligand ratio. All of the complexes are found to have an octahedral geometry, with the exception of the square planar copper (II) complexes. The corrosion inhibition of aluminium and copper in 1 M HCl and chromium–nickel steel in crude oil using III_n have been studied by weight loss method.     

Synthesis,crystal structure,and antimicrobial activity of a series of cobalt(III) Schiff base complexes

Abstract

A series of six new mononuclear Schiff base complexes, 1–6 of cobalt(III) of the general formula, [CoLX] or its adduct with methanol, is reported. The pentadentate Schiff base ligand (H₂L) was obtained by the condensation of N-(3-aminopropyl)-N-methylpropane-1,3-diamine with 1-(2-hydroxyphenyl)ethanone (H₂L¹) or 1-(2-hydroxyphenyl)propan-1-one (H₂L²). X stands for the pseudohalides, N₃^–, N(CN)₂^? , and NCS^–. The complexes have been synthesized by the reaction of equimolar amounts of cobalt(II) nitrate with H₂L¹ or H₂L² in the presence of the respective pseudohalide in methanol medium. All the complexes have been characterized by microanalytical, spectroscopic, single crystal XRD (except 3), and other physicochemical studies. Structural studies reveal that the central Co(III) ion in 1, 2, 4, 5, and 6 adopts a distorted octahedral geometry with a CoN₄O₂ chromophore. Weak intermolecular H-bonding and/or π-interactions are operative in these complexes to bind the molecular units. The antimicrobial activity of all the complexes and their constituent Schiff bases has been tested against some common bacteria and fungi.     

Action des Hydrazines Fluoroalkylées Sur Les α-Cetophosphonates: Synthèse des Hydrazones α-Phosphonylées N-Fluoroalkylées

In the present work, we study the reaction of fluorinated hydrazines H ₂ N-NHR _F with α-ketophosphonates 1, which lead to N-fluoroalkylated α-phosphonylated hydrazones 2. The stereochemistry of the hydrazones 2 was determined by multinuclear NMR experiments ( ¹ H, ¹³ C, ¹⁹ F, and ³¹ P) and IR spectroscopy.     

Solvent effects on the dimensionality of oxamato-bridged manganese(II) compounds

Abstract

Two new oxamate-containing manganese(II) complexes, [{Mn(H₂edpba)(H₂O)₂}₂]_n (1) and [Mn(H₂edpba)(dmso)₂]?dmso?CH₃COCH₃?H₂O (2) (H₄edpba = N,N′-ethylenediphenylenebis(oxamic acid) and dmso = dimethylsulfoxide), have been synthesized and the structures of 1 and 2 were characterized by single crystal X-ray diffraction. The structure of 1 consists of neutral honeycomb networks in which each manganese(II) is six-coordinate by one H₂edpba^2? ligand and two carboxylate–oxygens from two other H₂edpba^2? ligands building the equatorial plane. Each manganese is connected to its nearest neighbor through two carboxylate(monoprotonated oxamate) bridges in an anti-syn conformation. A dmso solution of single crystals of 1 was placed under acetone atmosphere affording 2, whereas putting 2 in equimolar water:ethanol mixture results in 1. The molecular structure of 2 is made up of mononuclear manganese(II) units which are interlinked by weak C–H?π and edge-to-face π-stacking interactions leading to supramolecular chains along the crystallographic b axis. Magnetic measurements reveal the occurrence of an antiferromagnetic coupling between two manganese(II) ions through anti-syn carboxylate bridges for 1 [J = ?1.18 cm^?1, the Hamiltonian being defined as H = ?J S₁^.S₂] and very weak intrachain ferromagnetic interactions in 2 [J = + 0.046 cm^?1, H = ?J ∑_iS_i^.S_i + 1].     

Construction of Cd(II) complexes based on 2-(1H-imidazol-1-methyl)-1H-benzimidazole and 1,4-benzenedicarboxylate

Three new Cd(II) complexes incorporating both 2-(1H-imidazol-1-methyl)-1H-benzimidazole (imb) and 1,4-benzenedicarboxylate (bdic^2?), [CdCl(bdic)_1/2(imb)₂]_n (1), {[Cd(bdic)(imb)(H₂O)]·DMF·2H₂O}_n (2), and [Cd(bdic)(imb)]·3H₂O}_n (3), have been prepared and structurally characterized by single crystal X-ray diffraction. Bdic^2? anions connect the?Cd-imb-Cd-imb?chains leading to a 2-D structure of 1. Bdic^2?(A) and bdic^2?(B) anions link the binuclear [Cd₂(imb)₂(H₂O)₂] units forming a 2-D structure of 2. Complex 3 features a 2-D structure involving supramolecular “double-layer” motifs. IR spectra and thermogravimetric curves are consistent with the results of the X-ray crystal structure analysis; 1–3 exhibit good fluorescence in the solid state at room temperature.     

Efficient synthesis of some novel furo[3,2-e]pyrazolo[3,4-b]pyrazines and related heterocycles

A series of novel 6-functionalized-5-amino-3-methyl-1-phenyl-1H-furo[3,2-e]pyrazolo[3,4-b]pyrazines (4a–c) was synthesized by the reaction of 3-methyl-6-oxo-1-phenyl-6,7-dihydro-1H-pyrazolo[3,4-b]pyrazine-5-carbonitrile (2) with α-halocarbonyl compounds such as: diethyl 2-bromomalonate, phenacyl bromide and chloroacetone. Cyclocondensation of the amino benzoyl 4b with diethyl malonate yielded the oxopyridine carboxylate derivative 5. Also, the starting intermediate amino ester compound 4a was allowed to react with ethanol amine to afford the hydroxyethyl caboxamide derivative 6. Furthermore, hydrazinolysis of the amino ester 4a afforded the corresponding amino carbohydrazide 7 which was used as a versatile precursor for synthesis of other heterocyclic compounds attached or fused to the furopyrazolopyrazine moiety. The chemical structures of the newly synthesized compounds were confirmed on the basis of elemental and spectral analyses containing FT-IR, ¹H NMR, ¹³C NMR, and mass spectrometry hoping these molecules should allow us to investigate their pharmacological activities in the future study.