نتایج جستجو برای: Solvent‐free reaction

تعداد نتایج: 412405  

Abdol Hajipour Amin Zarei Leila Khazdooz Nafisehsadat Sheikhan

A convenient and efficient procedure for the synthesis of 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes by condensation of 2-naphthol and aldehydes in the presence of Methylimidazolium hydrogensulfate, as a Brönsted acidic ionic liquid ([Hmim]HSO4), is described. Both aromatic and aliphatic aldehydes reacted easily to afford the corresponding 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes in good yiel...

Abdol Hajipour Amin Zarei Leila Khazdooz Nafisehsadat Sheikhan

A convenient and efficient procedure for the synthesis of 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes by condensation of 2-naphthol and aldehydes in the presence of Methylimidazolium hydrogensulfate, as a Brönsted acidic ionic liquid ([Hmim]HSO4), is described. Both aromatic and aliphatic aldehydes reacted easily to afford the corresponding 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes in good yiel...

Sayyed Zahra Sayyed-Alangi

The stable phosphonate derivatives have easily synthesized by the reactions involving trialkyl(aryl) phosphites and dimethyl acetylenedicarboxylate in the presence of 4-nitrophenol and/or acid chlorides, dialkyl(aryl) phosphites and N-methylimidazole at 70 oC under solventfree conditions.

2006
KENNETH M. DOLL RANDAL L. SHOGREN J. L. WILLETT GRAHAM SWIFT

Copolymers of citric acid and D-sorbitol were synthesized with a solventfree vacuum-oven synthesis with molar ratios of citric acid to D-sorbitol ranging from 1/1 to 6/1. The extent of the reaction was followed by the monitoring of the residual acid content of the system. As expected, the reaction occurred much more rapidly at 150 than at 110 8C. The Fourier transform infrared (FTIR) spectra of...

2009
Liang-Nian He Jin-Quan Wang Jing-Lun Wang

The development of catalytic methods for chemical transformation of CO2 into useful compounds is of paramount importance from a standpoint of C1 chemistry and so-called green chemistry. The kinetic and thermodynamic stability of CO2 molecule presents significant challenges in designing efficient chemical transformations based on this potential feedstock. In this context, efforts to convert CO2 ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1392

abstract in aggregate, active forms of reactive silica with mineral names are sometimes associated with sand and gravel in concrete mixture. alkali hydroxides originated from alkalis in the cement or other resources form an alkaline silica gel with this reactive silica which becomes swallowed and expanded during time causing damage to concrete. there have been growing researches on alkaline r...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1390

in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...

2012
Kadir Ozden Yerdelen

In this study, solvent-free and phase transfer catalysis conditions coupled with microwave irradiation and their advantages in synthesis of N-alkylation of primary anilines were reported. In this way two different microwave processing techniques were compared in terms of reaction yields. Consequently, microwave irradiation significantly reduced reaction times compared to traditional heating met...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید بهشتی - دانشکده علوم 1371

we describe here a suitable approach for the synthesis of n-unsubstituted monocyclic b-lactams under mild reaction conditions by the annelation of imines with substituted acetylchlorides. in this method the reaily available phtalimidoacetyl chloride were allowed to react with - dibenzylideneiminotoluene (hydrobenzamide) in the presence of an equimolar amount of triethylamine in refluxing toluen...

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