Brönsted acidic ionic liquid supported on rice husk ash (RHA–[pmim]HSO<sub>4</sub>): a highly efficient and reusable catalyst for the formylation of amines and alcohols
hydrogen sulfate. The immobilized acidic ionicliquid was characterized with a variety of techniques including infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and pH analysis. The catalytic performance of this heterogeneous ionicliquid was probed for the N-formylation of a variety of amines using formic acid under solvent free
In this work, nanoporous sodium montmorilloniteclay (Na+-MMT) was used as a support for the immobilization of 1-methyl-3-(trimethoxysilylpropyl)-imidazolium hydrogen sulfate. The Na+-MMT chemical modification ([Na+-MMT-[pmim]HSO4) was confirmed by a variety of techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron
Simultaneous Determination of C<sub>1</sub>−C<sub>4</sub> Carboxylic Acids and Aldehydes Using 2,4-Dinitrophenylhydrazine-Impregnated Silica Gel and High-Performance Liquid Chromatography
4-dinitrophenylhydrazides exhibited maximum absorption wavelengths of 331-334 nm and molarabsorption coefficients of 1.4 x 10(4) L/mol/cm. They were completely separated by high-performance liquid chromatography (HPLC) with an RP-Amide C16 column. Cartridges packed with DNPH-coated silica particles (DNPH cartridge) were used for sampling formic acid and aldehydes. Formic acid was physically adsorbed on
描述了一种同时测定空气中脂肪族羧酸和醛类的新方法。在这项工作中,使羧酸与2,4-二硝基苯肼(DNPH)反应形成相应的羧基2,4-二硝基苯肼。这些衍生物具有出色的热稳定性,其熔点比相应的高32-50摄氏度。C1-C4羧酸2,4-二硝基苯酰肼的最大吸收波长为331-334 nm,摩尔吸收系数为1.4 x 10(4)L / mol / cm。使用RP-Amide C16色谱柱的高效液相色谱(HPLC)将它们完全分离。使用装有DNPH涂层的二氧化硅颗粒的小柱(DNPH小柱)对甲酸和醛进行采样。作为采样机制的第一步,甲酸物理吸附在二氧化硅颗粒上。随后与DNPH逐渐反应。甲酸在室温(20摄氏度)下与DNPH反应非常缓慢,但在80摄氏度下历时4小时完全反应。在现场测量中,通过DNPH滤芯吸入样品空气。取样后,将小柱在80摄氏度下加热5小时,然后用乙腈萃取进行HPLC分析。在这些优化条件下,对于以100 mL
An eco-benign and highly efficient procedure for N-acylation catalyzed by heteropolyanion-based ionic liquids using carboxylic acid under solvent-free conditions
An eco-benign and highly efficient route for N-acylation of amines has been developed by treating amines with corresponding carboxylic acids in the presence of 2 mol % of heteropolyanion-based ionic liquids as catalysts under solvent-free conditions. This practical reaction could tolerate a wide range of substrates. Thus, various N-acylation products including N-acyl alpha-amino acid derivatives were obtained in moderate to excellent yields at 70 degrees C to 120 degrees C. Moreover, recycling studies revealed that heteropolyanion-based ionic liquids were easily reusable for this N-acylation. This method provides a green and much improved protocol over the existing methods.(c) 2014 Elsevier Ltd. All rights reserved.
A very simple and highly efficient procedure for N-formylation of primary and secondary amines at room temperature under solvent-free conditions
作者:Goutam Brahmachari、Sujay Laskar
DOI:10.1016/j.tetlet.2010.02.119
日期:2010.4
N-Formylation of primary and secondary amines has efficiently been carried out at room temperature in excellent yields by using catalytic amount of sodium formate in formic acid under solvent-free conditions. The process is remarkably simple and environmentally benign. (C) 2010 Elsevier Ltd. All rights reserved.