Comeplexes of 1-(2′-hydroxybenzyl)-2-(2′-hydroxyphenyl)-benzimidazole with U(VI) and Ce(IV)

Some new U(VI) and Ce(IV) complexes of 1-(2′-hydroxybenzyl)-2-(2′-hydroxyphenyl)-benzimidazole have been prepared and characterized by spectrg magnetic and conductance studies. IR spectral data suggests that the ligand in all the complexes is monodenate through the tertiary nitrogen and that the phenolic oxygen is free from coordination. Conductivity measurements indicate that the nitrate and acetate complexes of U(VI) are non-electrolytes, whereas the nitrate complex of Ce(IV) is a 1:1 electrolyte.     

2-Polyfluoroalkylchromones. 11. Synthesis and structures of 5-hydroxy-3-(2-hydroxyaryl)-5-polyfluoroalkyl-Δ2-pyrazolines and 3(5)-(2-hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles

The reaction of 2-hydroxy-2-polyfluoroalkylchroman-4-ones with hydrazine affords 5-hydroxy-3-(2-hydroxyaryl)-5-polyfluoroalkyl-²-pyrazolines, whereas 2-polyfluoroalkylchromones under similar conditions produce 3(5)-(2-hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles. 5-(2-Hydroxyaryl)-1-methyl-3-polyfluoroalkylpyrazoles were synthesized in the reaction with methylhydrazine, and the reaction with phenylhydrazine afforded regioisomeric 3(5)-(2-hydroxyphenyl)-1-phenyl-5(3)-polyfluoroalkylpyrazoles.     

Complexation equilibria and spectrophotometric determination of zinc (II) with 2-(4′-methyl-2′-thiazolylazo)-4,6-dimethylphenol

2-(4′-methyl-2′-thiazolylazo)-4,6-dimethylphenol has been synthesized and its acid—base behaviour (pK_a1=0.03 ± 0.01, pK_a2=9.70±0.09) and complexation equilibria with zinc (logβ₁₀₁=6.70±0.04, logβ₁₀₂ = 13.70±0.02) studied in a 40% (v / v) ethanol—water medium at I=0.25 M NaClO₄. A spectrophotometric method for the determination of 0.2–1.5 ppm of zinc has been developed (ε=1.83 × 10⁴ 1. mol⁻¹ cm⁻¹ at 590 nm) and applied to its determination in lubricating oils.     

Abnormal Reaction of 1-(2′-Methoxybenzoyl)-1-(2′-hydroxy-5′-methoxycarbonylbenzoyl)methane Treated with Etyyl Orthoformate and Acetic Anhydride

邻羟基二苯甲酰基甲烷与Ａｃ２Ｏ和ＨＣ（ＯＥｔ）３反应通常是ＨＣ（ＯＥｔ）３作为酰化剂，得到３－苯甲酰基色酮。本文报道５－甲氧羰基－２－羟基苯甲酰基－（２′－甲氧苯甲酰基）甲烷与Ａｃ２Ｏ和ＨＣ（ＯＥｔ）３反应时，是Ａｃ２Ｏ而不是ＨＣ（ＯＥｔ）３作为酰化剂，生成３－苯甲酰基－２－甲基色酮。其结构经ＮＭＲ、ＭＳ、ＩＲ和ＥＡ证实。并对其反应机理作了讨论。     

Complexation of copper(II) with 2′,2′-dialkyl-para-tert-butylbenzohydrazides

The complexation of copper(II) with 2′,2′-dimethyl-, 2′,2′-dibutyl-, and 2′,2′-diisobutyl-para-tert-butylbenzohydrazide in water-ethanol media was studied. The reagents (HL) formed [Cu(HL)]²⁺ and [Cu(HL)₂]²⁺ cationic complexes in a weakly acidic medium and uncharged CuL₂ complexes in an alkaline medium. logK _st was calculated for these complexes. The effect of 2′,2′-alkyl radicals on the stability of the complexes was considered. The obtained results were compared with data on the complexation of copper(II) ions with 2′,2′-dialkylbenzohydrazides.     

Reactions of 2(3′-oxoalkyl)-1,3-cyclohexanediones with nitrogenous reagents

Condensed 1,4-dihydropyridines, which do not contain a substituent in position 4 and which are formed in the reaction of 2-(3-oxoalkyl)-1,3-cycohexanediones with ammonium acetate in acetic acid, undergo disproportionation. Pyridine bases are formed as the result of two competing reactions: disproportionation and oxidation of 1,4-dihydropyridines, intermediates in the heterocyclization of oxo-1,3-diketones with participation of the nitrogen atom, by air oxygen.N. G. Chernyshevskii Saratov State University Saratov 410026. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 647–651, May, 1994. Original article submitted April 22, 1994.     

Reaction of 4-(2′-Hydroxyaryl)-1,3-dithiolium Salts with Sodium Sulfide. A Selective Synthesis of 2′-Hydroxyacetophenones

Abstract

The treatment of 4-(2′-hydroxyaryl)-2-(N,N-dialkylamino)-1,3-dithiolium perchlorates (1a–g) with sodium sulfide nonahydrate in ethanol at room temperature affords the corresponding 1,3-dithiole-2-thiones (2a–g). When these reactions are conducted in boiling ethanol, 2′-hydroxyacetophenones (3a–g) have been obtained in good to excellent yield. A tentative mechanism for the formation of 3a–g shows that this reaction is regioselective, this being established by the presence of hydroxyl group in 2′-position. That has been confirmed in a control experiment, 4-phenyl-2-(piperidin-1-yl)-1,3-dithiolium perchlorate affording a mixture of condensation products of acetophenone and phenylacetaldehyde, under similar reaction conditions.     

Complexes of palladium,platinum and rhodium with 2,2′-biquinoline and 2-(2′-pyridyl)quinoline

Summary The reactions of 2,2-biquinoline(biq) with M(PhCN)₂X₂ (M=Pd; X=Cl or Br; M=Pt, X=Cl, Br or I), K₂PtCl₄ and RhCl₃·3H₂O and of 2-(2-pyridyl)quinoline (pq) with K₂PtCl₄ and RhCl₃·3H₂O have been investigated. The isolated complexescis-[Pd(biq)X₂] (X=Cl or Br),cis-[Pt(biq)Cl₂],cis-[Pt(biq)Cl₂]·H₂O,trans-[Pt(biq)₂Br₂]·5H₂O, [Pt₃(biq)₂I₆],mer-[Rh(biq)Cl₃-(H₂O)] andmer-[Rh(pq)Cl₃(H₂O)] have been characterized by elemental analyses, conductivity measurements, i.r., electronic, and¹H n.m.r. spectra. The reaction of pq with K₂PtCl₄ in 1M H₂SO₄ gave the salt 2-(2-pyridyl) quinolinium tetrachloroplatinate(II) pentahydrate, (pqH)₂[PtCl₄]·5H₂O; when the reaction was carried out in aqueous acetone,cis-[Pt(pq)Cl₂] was obtained. A new method for the synthesis ofcis-[Rh(biq)₂X₂]X (X=Cl or Br) is described; both compounds have been further characterized by¹H n.m.r.     

High-spin complexes of iron(III) with ethylene glycol and 3(2′-hydroxyphenyl)-5-(4′-substituted phenyl) pyrazolines

Complexes of iron(III) with ethylene glycol and 3(2′-hydroxyphenyl)-5-(4′-substituted phenyl) pyrazolines, [Fe(OCH₂CH₂O)(C₁₅H₁₂N₂OX)] _m ? nH₂O and [Fe(C₁₅H₁₂N₂OX)₂(OCH₂CH₂OH)] (where OCH₂CH₂O and OCH₂CH₂OH = ethylene glycol moiety; C₁₅H₁₂N₂OX = 3(2′-hydroxyphenyl)-5-(4-X-phenyl)pyrazoline; X = H, CH₃, OCH₃, or Cl; m = 2–3 and n = 2–3) have been synthesized and characterized by elemental analysis (C, H, N, Cl, and Fe), molecular weight measurement, magnetic moment data, thermogravimetric analysis, molar conductance, spectral (UV-Vis, IR, and FAB mass), scanning electron microscopy, and X-ray diffraction studies. Bonding of ethylene glycol and pyrazolines in these complexes and the particle size of iron(III) complexes are discussed. Antibacterial and antifungal potential of free pyrazoline and some iron(III) complexes are also discussed.     

A Facile Synthesis of an Advanced Glycosylation Endproduct 2-(2′-furoyl)-4(5)-(2′-furanyl)-1H-imidazole

Abstract: A three step synthesis of the advanced glycosylation endproduct 2-(2′-furoyl)-4(5)-(2′-furanyl)-1H-imidazole (4, FFI) has been achieved from 2-acetylfuran. The key step in the synthesis was the rearrangement of the hydrazinium bromide 3 in refluxing methanol.     

Synthesis of (Z)-(2′R)-1-O-(2′-methoxynonadec-10′-enyl)-sn-glycerol,a new analog of bioactive ether lipids

An unsaturated 2-methoxy-substituted 1-O-alkylglycerol, (Z)-(2′R)-1-O-(2′-methoxynonadec-10′-enyl)-sn-glycerol, a new analog of bioactive ether lipids, was synthesized from oleic acid and 2,3-isopropylidene-sn-glycerol. The two key steps of this synthesis were the conversion of oleyl aldehyde to a monounsaturated epoxide using Matteson’s method followed by hydrolytic kinetic resolution and a nucleophilic epoxide opening by 2,3-isopropylidene-sn-glycerol in the presence of potassium tert-butoxide in anhydrous DMF, which appeared to be a good reagent for this purpose. Furthermore, the diol by-product of the HKR process was also easily converted back to the starting epoxide thus almost doubling the amount of target molecule.     

Spectroscopic and structural properties of complexes of 3,3′-bis(2-benzimidazolyl)-2,2′-bipyridine with copper(I) and silver(I)

The pseudo-tetrahedral complexes [CuL₂]PF₆·7H₂O·CH₃OH (1) and [AgL₂]CF₃SO₃·H₂O (2) (L?=?3,3′-bis(2-benzimidazolyl)-2,2′-bipyridine) have been synthesized and characterized through crystal structure analyses, electrochemistry, and spectroscopic methods. X-ray structural analyses of 1 and 2 indicate that sterically constrained N₄ ligands L are cis and behave as bidentate chelates to a single metal ion in a pseudo-tetrahedral fashion through the benzimidazole. As two benzimidazolyl rings exhibit considerable steric hindrance, the bipyridine unit of L remains uncoordinated. The pseudo-tetrahedral cation [CuL₂]⁺ shows a quasi-reversible Cu^I/Cu^II oxidation–reduction wave in the CV in DMF (counter-ion PF₆^?). The fluorescence titration of L with copper(I), silver(I), and also with pH have been conducted to examine the selectivity. The ligand shows remarkably high selectivity and sensitivity for Ag(I).     

Lanthanide complexes with bis(2′-quinolyl)-2,6-pyridine

Complexes of lanthanide (III) nitrates, thiocyanates and perchlorates with the tridendate ligand, bis(2′-quinolyl)-2,6-pyridine are reported. The molar conductivity values in acetonitrile-benzene mixture (80−20) and IR data indicate that the nitrate and thiocyanate complexes are non electrolytes and the perchlorate 1:3 electrolytes. The electronic spectra of the Pr, Nd, Ho, and Er complexes show enhancement of intensities for the hypersensitive bands; moreover, except in the case of the Er^III complexes, where a very slight red shift is observed, other complexes show the expected nephelauxetic effect.     

Transition metal(II) complexes of 1-(α-hydroxynaphthyl)-2-(3′-methyl-5′-mercapto-1′,2′,4′-triazole)-2-aza-ethane

Summary Binuclear metal complexes of the type [M(HMTE)-(H₂O)₂]₂, where HMTE=1-(-hydroxynaphthyl)-2-(3-methyl-5-mercapto-1,2,4-triazolc)2-aza-ethane and M-Cu^II, Co^II, Ni^II and Mn^II have been prepared and characterized. An octahedral geometry around the metals is proposed. The complexes have been screened as possible fungicides.     

Synthesis and X-ray structural characterization of dioxomolybdenum(VI) complexes with N′-(5-chloro-2-hydroxybenzylidene)-4-methylbenzohydrazide and N′-(2-hydroxybenzylidene)-4-methylbenzohydrazide

Two new dioxomolybdenum(VI) complexes, [MoO₂(ClHm)(CH₃OH)] (I) and [MoO₂(Hm)(CH₃OH)] (II) with the hydrazone ligands H₂ClHm and H₂Hm derived from 4-methylbenzohy-drazide with 5-chlorosalicylaldehyde and salicylaldehyde, respectively, have been synthesized and structurally characterized by physicochemical methods and single-crystal X-ray determination. The crystal of I crystallizes in the triclinic space group \(P\bar 1\), with a = 7.839(2), b = 9.656(3), c = 11.548(4) Å α = 88.885(3)°, β = 87.454(3)°, γ = 88.996(3)°, V = 873.0(5) ų, Z = 2, R ₁ = 0.0292, wR ₂ = 0.0685, S = 1.092. The crystal of II crystallizes in the triclinic space group \(P\bar 1\), with a = 7.780(2), b = 10.584(3), c = 10.628(3) Å, α = 91.462(3)°, β = 104.818(3)°, γ = 103.288(3)°, V = 820.1(4) ų, Z = 2, R ₁ = 0.0403, wR ₂ = 0.0784, S = 1.065. An X-ray analysis indicates that the structures of both complexes are similar to each other. The molybdenum atom in each complex is in an octahedral coordination environment constructed by two oxo groups, an NO₂ donor set of the hydrazone ligand, and one methanol O atom.     

Synthesis and Structure Determination of (2S, 2′S)-3-Phenyl-2-(pyrrolidin-2′-yl)- propionic Acid

Abstract

Aβ²,β³-homoproline derivative, (2S, 2′S)-3-phenyl-2-(pyrrolidin-2′-yl)propionic acid, was synthesized starting from l-proline. After preparation of the (4S, 4aS)-4-benzyl-4a,5,6,7-tetrahydro-pyrrolo-[1,2-c]pyrimidine-1,3-dione under a mild condition, the absolute configuration of target compound was assigned using 2D H-H COSY and H-H NOESY technologies.     

Synthesis of 2-(3′Bromo-3′-phenylallyl)indoles via ZnBr2-Mediated Addition of Bromomethylindoles/Indolylmethylacetates with Phenylacetylene

Abstract

An efficient synthesis of 2-(3′-bromo-3′-phenylallyl)indoles has been developed via direct carbon–carbon bond formation between bromomethylindoles/indolylmethylacetates and phenylacetylene.     

A Kinetic Fluorimetric Method for Determination of Microamounts of Pt(IV) with 2-2′ Dipyridylketone Hydrazone

Abstract

A kinetic method for determination of traces of Pt(IV) based on the aerobic oxidation of the hydrazone of 2-2′ dipyridylketone, in which the formation of a fluorescent product (λ_ex = 359 nm, λ_em = 435 nm) takes place, is described. The reaction is followed by the measurement of the rate of appearance of the fluorescence. The proposed method suffers very few interferences.     

Lanthanide Complexes with N,N′-Bis(2- hydroxybenzylidene)-2-hydroxyphenylmethanediamine

Complexes of lanthanides with N,N-bis(2-hydroxybenzylidene)-2-hydroxyphenylmethanediamine (H₃L) were synthesized and investigated by the elemental, IR, magnetochemical, and thermogravimetric methods. Using the data obtained, they were found to have compositions Ln₂L₂ · nH₂O and La₂L₂ · MCl₂ · 4H₂O (Ln = La³⁺, Pr³⁺, Nd³⁺, Dy³⁺, Er³⁺; M = Cu²⁺, Co²⁺, Ni²⁺; n = 4, 6). Suggestions on their structures were made. In the interval of 20–140°C, these complexes were shown to be high-resistance semiconductors.