نتایج جستجو برای: acid catalyst
تعداد نتایج: 784490 فیلتر نتایج به سال:
Three kinds of HZSM-5 nanoparticles with different acidity were tailored by impregnating MgO or varying Si/Al ratios. Both the textural and acidic properties of the as-prepared nanoparticles were characterized by nitrogen adsorption-desorption measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), ammonia temperature-programmed desorption (NH3-TPD) and Fourier transform infr...
A Periodic Mesoporous Organosilica (PMO) functionalized with sulfonic acid groups has been successfully synthesized via a sequence of post-synthetic modification steps of a trans-ethenylene bridged PMO material. The double bond is functionalized via a bromination and subsequent substitution obtaining a thiol functionality. This is followed by an oxidation towards a sulfonic acid group. After fu...
1-Methyl-3-(2-oxyethyl)-1H-Imidazol-3-ium-Borate Sulfonic Acid ([MOEI]-BSA) was easily prepared and used as a new and highly efficient solid acid catalyst for the synthesis of benzimidazole derivatives with high isolated yields. Various substituted benzimidazoles were synthesized by a combination of o-phenylenediamines and aldehydes in the presence of [MOEI]-BSA with excellent yields in water a...
α-Hydroxy ketones are valuable synthons in organic chemistry. Here we show that oxidation of vic-diols to α-hydroxy ketones with H2O2 can be achieved with an in situ prepared catalyst based on manganese salts and pyridine-2-carboxylic acid. Furthermore the same catalyst is effective in alkene epoxidation, and it is shown that alkene oxidation with the MnII catalyst and H2O2 followed by Lewis ac...
The cascade reaction sequence is a fascinating subject in catalysis. A rationally designed cascade reaction sequence can simplify the synthetic route, reduce the amount of waste and lower the operation cost. The key for a successful cascade reaction sequence is the multifunctional catalyst. With a suitable multifunctional catalyst, multiple synthesis steps can proceed in one pot with high yield...
silica-bonded n-propyldiethylenetriamine sulfamic acid (spdtsa) is employed as a recyclable heterogeneous solid acid catalyst for the synthesis of benzopyrano[2,3-d]pyrimidines through one-pot condensation reaction of salicylaldehydes, malononitrile and secondary amines at room temperature under solvent-free conditions. spdtsa showed much the same efficiency when used in consecutive reaction ...
N-methylol compounds, such as dimethyloldihydroxyethyleneurea (DMDHEU), are the most commonly used durable press finishing agents for cotton fabrics by the industry. In this research, we have examined the effects of the catalyst systems used for DMDHEU on the mechanical strength of the crosslinked cotton fabric. The catalysts induce degradation of cellulose as indicated by the decrease in the t...
A simple solvent-free protocol for the preparation of flunixin, a potent non-narcotic, non-steroidal anti-inflammatory drugs is reported using boric acid as catalyst. Its salt, flunixin meglumine are then prepared under reflux in EtOH. This sustainable method are then extended for the synthesis of a series of 2-(arylamino) nicotinic acid derivatives. The present protocol combines non-hazardous ...
nanocrystalline sio2–hclo4, as a newly reported catalyst, has been used as an efficient and reusable catalyst for the synthesis of pyrimidine derivatives. the procedure can be successfully applied to the efficient synthesis of mono substituted pyrimidine derivatives, using triethyl orthoformate, ammonium acetate, methyl ketone derivatives. in practice, this method is a combination of a satisfac...
Correction We found an important error in our published paper [1]. On page 7, Section: One-step conversion of Jatropha oil to biodiesel, line 3, we wrote a reaction temperature of 120degreesC. The correct temperature should be 220degreesC. The pressure was also omitted from the same reaction description and should be 7.1 MPa. Direct production of biodiesel from high-acid value Jatropha oil with...
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