- An aminoimidazole and its utility in heterocyclic synthesis
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Aminoacetonitrile (1) reacted with acetamidinium chloride to give 4-aminoimidazole (4), which reacted with DMFDMA to yield imidazole derivative 7 and with benzylidinemalononitrile and ethoxymethylene malononitrile to give imidazo[1,5-a]pyrimidine derivatives 12 and 15. Compound 1 reacted with β-crotononitrile to yield pyridine derivative 20. Imidazo[1,2-a]pyridine derivative 23 could be obtained via the reaction of 20 with DMFDMA.
- Elkholy, Yehya M.,Erian, Ayman W.
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- Synthesis and characterization of go-chit-ni nanocomposite as a recoverable nanocatalyst for reducing nitroarenes in water
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In the present study, nickel nanoparticles (Ni-NPs) immobilized on graphene oxide-chitosan (GO-Chit-Ni) have been synthesized and characterized as a catalyst for reduction of nitroarenes in water. For this purpose, GO has been functionalized with chitosan (GO-Chit). Then, Ni-NPs were immobilized on the surface of GO-Chit using a simple method. The GO-Chi-Ni nanocomposites were characterized using Fourier Transforms Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), X-Ray Diffraction Measurements (XRD), and Atomic Adsorption Spectrometry (AAS). The GO-Chi-Ni nanoparticles demonstrated appropriate catalytic activity in reducing nitroarenes to aryl amines in the existence of sodium borohydride (NaBH4) aqueous solution as a hydrogen source at 80oC. This catalytic system applies environmentally benign water as a solvent that is cheap, easily accessible, non-toxic, non-volatile, non-flammable and thermally stable. This type of catalyst can be applied several times with no considerable change in its performance.
- Azadi, Roya,Sarvestani, Mosayeb
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p. 523 - 531
(2020/07/17)
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- Magnetically Recoverable Gold Nanorods as a Novel Catalyst for the Facile Reduction of Nitroarenes Under Aqueous Conditions
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Abstract: In this work, cysteine-functionalized Fe3O4@Carbon magnetic nanoparticles were used for the synthesis of gold nanorods. Fe3O4@C nanoparticles were first prepared by synthesis of Fe3O4magnetic nanoparticles (MNPs), and then carbon-coated MNPs (Fe3O4@C) were synthesized by glucose carbonization using a hydrothermal method. Finally, the gold NRs were loaded on the modified surface of Fe3O4@C MNPs. The designed magnetically recoverable gold nanorods, after full characterization by FTIR, SEM, TEM, TGA, VSM, XRD, and ICP-OES, were applied to the reduction of nitroarenes. The Fe3O4@C@Cys–Au nanorods showed higher performance than Fe3O4@C@Cys–Au nanospheres in a selective facile reduction of nitroarenes to the corresponding aminoarenes in aqueous medium at room temperature using NaBH4. Graphical Abstract: [Figure not available: see fulltext.]
- Lamei, Kamran,Eshghi, Hossein,Bakavoli, Mehdi,Rostamnia, Sadegh
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p. 491 - 501
(2017/02/18)
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- Novel imidazole compounds and use of these compounds for dyeing keratinous fibers
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The disclosure relates to novel imidazole compounds which can be useful as couplers for the oxidation dyeing of keratinous fibers. The present disclosure also relates to a dyeing composition for dyeing keratinous fibers comprising at least one oxidation base and at least one coupler of the imidazole type as disclosed herein, and the dyeing method using this composition.
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- Efficient reduction of nitroarenes in water catalyzed by reusable Pd nanoparticles immobilized on chitosan-functionalized graphene oxide
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Graphene oxide was functionalized with chitosan for palladium immobilization (GO-Chit-Pd), which was used as an efficient catalyst for the reduction of aromatic nitro compounds using sodium borohydride in water. To achieve the best catalytic efficacy, various parameters such as temperature, solvent, mole ratio of hydrogen sources, and the amount of catalyst were optimized. The method has been applied to the reduction of a broad range of nitroarenes with different properties. The easy purification, convenient operation, environmental friendliness, and high product yields render this method viable for use. The nanocatalyst can be easily separated and efficiently recovered and reused for multiple cycles without appreciable loss in its catalytic activity.
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