Tandem Oxidation Process Using Ceric Ammonium Nitrate: Three-Component Synthesis of Trisubstituted Imidazoles Under Aerobic Oxidation Conditions

By combining a ceric ammonium nitrate (CAN)–catalyzed aerobic oxidation of α-hydroxy ketones with a subsequent three-component condensation reaction using aldehydes and ammonium acetate, highly substituted imidazole derivatives can be assembled. This reaction is an important approach for the synthesis of highly substituted imidazole derivatives and was carried out in good to excellent yields in ethanol as an environmentally benign solvent.     

New catalysts of Biginelli reaction

A synthesis was developed of new imidazole derivatives catalyzing three-component condensation of ethyl acetoacetate, aromatic aldehydes, and urea(or thiourea) by Biginelli reaction.     

Brønsted-acidic ionic liquid: green protocol for synthesis of novel tetrasubstituted imidazole derivatives under microwave irradiation via multicomponent strategy

Research on Chemical Intermediates - We present a facile and environmentally benign protocol for synthesis of variously substituted imidazole derivatives via multicomponent condensation of benzil,...     

Research on benzimidazole derivatives

Mercapto derivatives of benzimidazole and imidazole undergo condensation with 2,3-dichloro-1,4-naphthoquinone to give 1,4-naphthoquinonyl derivatives, which can be cyclized to cdioxo derivatives of condensed azole systems.See [2] for communication XXXIX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 783–785, June, 1976.     

Synthesis of Novel Chiral Thioether Ligands Containing Imidazole Rings Based on Natural Amino Acids

Using commercially available natural amino acids (L-Val, L-Leu, L-Phe) as chiral precursors, a series of N-substituted imidazole derivatives containing chiral groups was synthesized from the condensation reaction of amino acids, formaldehyde, glyoxal, and ammonia. Through esterification, reduction, chlorination, and subsequent substitution by thiols, chiral thioethers containing imidazole rings were synthesized, and the synthetic conditions were optimized. All the intermediates and the final products were characterized by NMR, ESI MS, HR MS, and IR.     

Efficient Synthesis of Phosphono‐ and Phosphinoxidomethylated N‐Heterocycles under Solvent‐Free Microwave Conditions

Simple N‐heterocycles were converted to N‐phosphono‐ and phosphinoxidomethyl derivatives by a solvent‐free microwave‐assisted condensation of the heterocycle, paraformaldehyde, and diethylphosphite or diphenylphosphine oxide in a convenient and, in most cases, efficient way. In contrast to an earlier report, imidazole proved to be unreactive in this type of phospha‐Mannich reaction.     

New and practical method for synthesis of 1- and 1,3-substituted xanthines.

[reaction: see text] A new and practical method for the synthesis of 1- and 1,3-substituted xanthines is reported. Direct base-promoted condensation of the imidazole precursor 1 with carbamates 2 gives 1-substituted 7-PMB xanthines 7 in good yields. Alkylation of these derivatives or their potassium salts proceeds under mild conditions to give functionalized 1,3-substituted 7-PMB xanthines 9 in good to excellent yields. The obtained 7-PMB-protected derivatives can be readily deprotected to give the parent 1- and 1,3-substituted xanthines.     

New chiral CuII complexes and their catalytic activity in enantioselective Henry reaction

New chiral polydentante ligands capable of complexation of Cu²⁺ ions were synthesized using readily available derivatives of (S)-proline, d-glyceraldehyde, and imidazole as the starting materials. The synthesized complexes are efficient catalysts for enantioselective nitroaldol condensation (the Henry reaction).     

Toward selectivity control of a heme peptide electrode by modification with a phase-transition polymer.

Reduction currents for H2O2 at a heme peptide (HP)-modified electrodes are suppressed by inhibitors, such as imidazole derivatives. Although this inhibition effect allows determinations of the total inhibition ability of imidazole derivatives, it has no selectivity. In this study the selectivity control of HP-modified electrodes for imidazole derivatives was performed utilizing the thermoresponsive phase transition of poly(N-isopropylacrylamide), which was chemically immobilized on HP-modified electrodes. The inhibition ratios for imidazole derivatives appeared to be small at temperatures below the lower critical solution temperature (LCST), and to be large above the LCST. This change was ascribed to a steric hindrance caused by a phase transition of the polymer. On the other hand, the inhibition ratio for histamine, which has a larger molecular size relative to imidazole, was not significantly changed by the phase transition. Thus, the selectivity of the HP-modified electrode was found to be controllable using an immobilized phase-transition polymer.     

1-Iminoalkylimidazoles via cuprous imidazolide

1-Iminoalkylimidazoles are obtained from the novel reaction of cuprous imidazolide with alkyl halides and nitriles. The condensation produces a new class of imidazole derivatives and the ease of the reactions suggests a reasonable scope. The compound N-(1-N-t-butylimino)ethylimidazole exhibits nematicidal activity against larvae of Meloidogyne javanica at 1 ppm.     

Influence de l'imidazole,de quelques sels métalliques et de mélanges imidazole/sel métallique sur des réactions de condensation «prébiotiques» induites par les polyphosphates en milieu aqueux

Influence of imidazole, metal salts and mixtures of imidazole/metal salt on ‘prebiotic’ condensation reactions induced by polyphosphates in aqueous solutions In the presence of imidazole, aqueous solutions 0.1 M in glycine and 0.1 M in sodium trimetaphosphate, at pH 8.0–8.6 and room temperature, yield after 14 days up to 3% of triglycine. Addition of Cd²⁺ or Zn²⁺ decreases the yields, while Mg²⁺ increases them slightly. The significance of the systems trimetaphosphate/imidazole and trimetaphosphate/imidazole/magnesium salt in the promotion of ‘prebiotic’ condensation reactions in aqueous solutions, especially the condensation of amino acids, is discussed.     

Syntheses and biological activity of chalcones-imidazole derivatives

A number of novel 13-membered chalcone-imidazole derivatives were prepared and have been synthesized and characterized by IR, ¹H NMR, ¹³C NMR and elemental analysis, the results conformed well to expected structures. Substituted acetophenones and benzaldehydes were condensed using the Claisen–Schmidt base-catalyzed aldol condensation. Methyl on the aromatic ring of chalcones was brominated by NBS, and then the resulting mixture was reacted with imidazole to get the target compound. Several chalcones showed in vitro antibacterial activity against Gram-bacterial. The results showed that these are potential antibacterial compounds.     

豆腐果苷-咪唑衍生物的合成及镇静活性研究

以豆腐果苷、2-羟基-1,2-二芳基乙酮(2a～2d)、乙酸铵和脂肪胺为原料,碘单质作为催化剂,成功地合成了一系列豆腐果苷-咪唑类衍生物4a～4h,新化合物4a～4h的结构经~1H NMR,~(13)C NMR,IR和HRMS确认.并用小白鼠实验对目标化合物4a～4h进行了镇静活性筛选,其中4e(400mg·kg~(-1))与豆腐果苷相比有较强的镇静活性.     

Luminescent study on the binding interaction of bioactive imidazole with bovine serum albumin-A static quenching mechanism

Novel bioactive imidazole derivatives were synthesized and characterized by NMR spectra, mass and CHN analysis. The interaction between the imidazole derivative and bovine serum albumin (BSA) was investigated by fluorescence and UV-vis absorption spectroscopy. The fluorescence quenching of BSA by the imidazole derivatives may be due to the formation of imidazole-BSA complex. The fluorescence quenching mechanism of BSA by imidazole was analyzed and the binding constant has been calculated. The binding distance between imidazole and BSA was obtained based on Forester's non-radiation energy transfer (FRET). The effect of some common ions on the binding constant between imidazole and BSA was also examined.     

A practical and green approach towards synthesis of multisubstituted imidazoles using boric acid as efficient catalyst

An efficient one-pot, cyclocondensation of ammonium acetate, 1,2-diphenyl ethanedione, aromatic aldehyde or arylamine, and catalyzed by boric acid is achieved to form multisubstituted imidazole derivatives. Boric acid as green property is harmless to the environment and has improved the yield of multisubstituted imidazole derivatives. Moreover, we have tested the biological activities of imidazole derivatives by the four fungi. And the investigations showed most of imidazole derivatives have antifungal action on four fungus.     

An expedient one-pot synthesis of highly substituted imidazoles using supported ionic liquid-like phase（SILLP） as a green and effcient catalyst and evaluation of their anti-microbial activity

An effcient method for the synthesis of imidazole derivatives by a three-component condensation of benzil or 9,10-phenanthrenequinone,aldehydes and ammonium acetate using supported ionic liquidlike phase（SILLP）catalyst under ultrasonic irradiation or classical heating conditions is reported.The present methodology offers several advantages,such as excellent yields,simple procedures,short reaction times,simple work-up and mild conditions.The catalyst is easily separated from the products by fltration and also exhibits remarkable reusable activity.These highly substituted imidazoles were also evaluated for their anti-microbial activity.     

Polymer-supported zinc chloride: a highly active and reusable heterogeneous catalyst for one-pot synthesis of 2,4,5-trisubstituted imidazoles

Abstract  A polymer-supported Lewis acid catalyst was prepared and found to be extremely efficient for the preparation of imidazole derivatives via three-component condensation of benzil, aldehydes, and ammonium acetate under mild conditions. The catalyst is stable and can be easily recovered and reused at least four times without any loss of activity. Graphical Abstract        

Synthesis of Bi- and tridentate imidazole ligands

A number of imidazole derivatives were prepared in the course of studying the limits of carbon-metal bond formation in complexes of imidazole with first-row transition metals. Seven of the compounds were new. The 4- and 5-methyl and 4,5-dimethyl derivatives of l-(2-pyridyl)-imidazole were prepared by reaction of the appropriate imidazole with 2-bromopyridine. Alkylation of imidazole, 4,5-dimethylimidazole, and benzimidazole with 2-chloromethylpyridine gave a series of 1-(2-pyridylmethyl)imidazoles. 1-(2,3-Diaminopropyl)imidazole was prepared in six steps via a Gabriel sequence.     

A novel approach to study the inclusion mechanism of imidazole derivatives in micellar chromatography

A chromatographic approach was proposed to describe the existence of surfactant micelles in a surfactant/hydroorganic phosphate buffer mobile phase. Using this mixture as a mobile phase, a novel mathematical theory is presented to describe the inclusion mechanism of imidazole derivatives in surfactant micelles. Using this model, enthalpy, entropy and the Gibbs free energy were determined for two chromatographic chemical processes: (i) the transfer of the imidazole derivative from the mobile phase to the stationary phase; and (ii) the imidazole derivative inclusion in surfactant micelles. These thermodynamic data indicate that the main parameter determining chromatographic retention is distribution of the imidazole derivatives to micelles of surfactant while the interaction with the stationary phase play a minor role.     

某些1-酰基苯并咪唑及1-酰基咪唑衍生物的合成

2-取代的苯氧甲基苯并咪唑、咪唑分别与酰氯在缚酸剂存在下反应,制备了24个新的1-酰基2-苯氧甲基苯并咪唑及1-苯氧乙酰咪唑衍生物.后者容易吸水,转变成相应的铵盐.所制得的化合物中某些经小麦垂直生长法测定表现出一定的促进或抑制生长活性.