Synthesis of p-Aminophenol by Catalytic Hydrogenation of Nitrobenzene

Organic Process Research & Development - ORG PROCESS RES DEV 11/1999; 3(6). DOI: 10.1021/op990040r

ABSTRACT The present work describes the preparation of p-aminophenol via single-step catalytic hydrogenation of nitrobenzene in acid medium. A conventional method of synthesis of p-aminophenol is a two-step reaction involving iron−acid reduction of p-nitrophenol. This method causes serious effluent disposal problems due to the stoichiometric use of iron−acid, which leads to the formation of Fe−FeO sludge (1.2 kg/kg of product) in the process, which cannot be recycled. The single-step hydrogenation of nitrobenzene was carried out using platinum catalyst, and the process conditions were optimized. Complete conversion of nitrobenzene was achieved with selectivity to p-aminophenol as high as 75% under the best set of conditions. Furthermore, the catalyst can be easily recovered and efficiently recycled giving the TON as high as 1.38 × 10.5 This paper presents studies on the effect of various process parameters such as temperature, hydrogen pressure, and substrate and acid concentration on the rate of reaction and selectivity to p-aminophenol.

  • [Show abstract] [Hide abstract]
    ABSTRACT: One pot synthesis of Ni nanoparticles were carried by solution reduction process successfully in aqueous media by using hydrazine hydrate as a reducing agent. Greener stabilizing agent Starch is used as a stabilizer which also acts as a particle protector towards oxidation. The morphology of the synthesized Ni nanoparticles were characterized by TEM and XRD. The prepared Ni nanoparticles were used as a catalyst in the reduction of p-Nitrophenol to p-Aminophenol under hydrothermal condition in the presence of Sodium borohydrate as a source of hydrogen. The conversion was excellent (97%) as confirm by LCMS. This also confirmed by the UV-Visible spectrum study of the reaction mixture. The Ni nanoparticles were recycled for at least five times without much loss in the catalytic activity.
    Synthesis and Reactivity in Inorganic Metal-Organic and Nano-Metal Chemistry 01/2012; · 0.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: New catalyst, prepared through Au nanoparticles anchored on the Ionic Liquid of 3,4,9,10-perylene tetracarboxylic acid-noncovalent functionalized graphene (Au/PDIL-GS), was fabricated using a facile and environment-friendly approach. The information of the morphologies, sizes, dispersion of Au nanoparticles (NPs) and chemical composition for the as-prepared catalysts was verified by systematic characterizations, including transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectra, X-ray diffraction (XRD) and X-Ray photoelectron spectroscopy (XPS). As a new catalyst, the resulting Au/PDIL-GS exhibited excellent catalytic activity in the reduction of 4-nitrophenol because of the synergistic effect between the PDIL-GS and Au NPs. The facile and environment-friendly approach provides a green way to effectively synthesize low cost Au-based catalysts for 4-NP reduction and is promising for the development of other useful materials.
    Journal of hazardous materials 01/2014; 270C:11-17. · 4.14 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: An easy one step and scalable process for the synthesis of multilayer macroporous polymer and carbon films is demonstrated by using spin coated thin films of polyacrylonitrile (PAN) in N, Ndimethyl formamide (DMF) solvent followed by their carbonization. The interconnected porous carbon films were characterized by various techniques including SEM, HRTEM, Raman, XRD, BET and AFM. Phase separation/dewetting in sub-micrometer thick films spontaneously produced a macroporous (pore diameter > 50 nm) polymer films with hole density in the range of 108 – 109 per cm2 and BET area of ~175 m²/g. Increased porosity can be tailored under the conditions that favor greater destabilization of the spin coated films such as reduced film thickness, higher evaporation rate and lower viscosity. Further, Ag/carbon hybrid films were prepared by incorporation of a silver salt in the solution prior to spin coating. The Ag/carbon porous films show good activity in the reduction of para-nitrophenol to para-aminophanol with sodium borohydride.
    Colloids and Surfaces A Physicochemical and Engineering Aspects 03/2013; · 2.11 Impact Factor