نتایج جستجو برای: acid catalyst

تعداد نتایج: 784490  

Abbas Daraie Abdollah Javidan Mohammad javad Taghizadeh

Modafinil (Diphenyl methyl Sulfinyl acetamid) is used clinically in the treatment of narcolepsy and sleeping disorders. The synthesis of R-modafinil, have started with the reaction of benzhydrol and thioglycolic acid in trifluoroacetic acid to afford benzhydryl sulfanyl acetic acid. The reaction of acid with thionyl chloride in benzene followed by treatment with ammonium hydroxide gave acetamid...

A water soluble, Bronsted acid, 5-sulfosalicylic acid as an efficient organocatalyst was used for the synthesis of physiologically active 2-substituted benzimidazole derivatives from o-phenylenediamine and aromatic aldehydes in ethanol at reflux condition. Cost-effectiveness, use of non-hazardous solvents, metal free and commercially available catalyst, single-step, environmentally fri...

2014
KAI HUANG MINGZHENG ZHANG GUANGZHI ZHANG XUE JIANG DAN HUANG

The esterification of rice straw fiber with acetic anhydride, using sulphuric acid as catalyst, under mild conditions in glacial acetic acid, has been investigated. Acetylation conditions, such as dosage of chemicals and catalyst, and time and temperature of acetylation, were optimized. The preferred reaction parameters of acetylation reaction are described as follows: weight ratio of rice stra...

[B(OH)3]0.78[B(OH)2(OSO3H)]0.22 or (BSA) was simply prepared by addition of chlorosulfonic acid to commercial boric acid at room temperature. This cheap and green solid acid was used as an efficient catalyst for synthesis of acylals from aldehydes under solvent-free conditions at room temperature.

[B(OH)3]0.78[B(OH)2(OSO3H)]0.22 or (BSA) was simply prepared by addition of chlorosulfonic acid to commercial boric acid at room temperature. This cheap and green solid acid was used as an efficient catalyst for synthesis of acylals from aldehydes under solvent-free conditions at room temperature.

2013
Hossein Naeimi Zahra Sadat Nazifi

ABSTRACT The functionalization of silica-coated Fe3O4 magnetic nanoparticles (Fe3O4@SiO2) using chlorosulfonic acid were afforded sulfonic acid-functionalized magnetic Fe3O4 nanoparticles (Fe3O4@SiO2-SO3H) that can be applied as an organic-inorganic hybrid heterogeneous catalyst. The used Fe3O4 magnetic nanoparticles are 18-30 nm sized that was rapidly functionalized and can be used as catalyst...

2012
Jincheng Ding Zheng Xia Jie Lu

Oils with high content of free fatty acid (FFA) can be treated by acid esterification where an alcohol reacts with the given oil in the presence of acid catalyst. The investigated parameters include methanol to oil ratio, temperature and amount of catalyst. The optimum conditions for acid esterification which could reduce FFA content in the feedstock to less than 1.88% (acid value 3.76 mg KOH/g...

Ammonium monovanadate (NH4VO3) has been devoted as an efficient, commercially available, eco-friendly and reusable catalyst for the synthesis of bis(indolyl)methanes (BIMs), oxindole derivatives and also Michael adducts of indoles at 50 °C under solvent-free conditions. The reusability of this solid acid catalyst in addition with its selectivity has also been examined.

A highly efficient, simple and clean solvent-free protocol for the synthesis of polyhydroquinolines is described. The one-pot multi-component condensation reaction between arylaldehydes, dimedone (5,5-dimethylcyclohexane-1,3-dione), β-ketoesters and ammonium acetate in the presence of catalytic amount of (2.5 mol%) melamine trisulfonic acid (MTSA) as a recyclable, green and attractive sulfonic ...

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