Synthesis of Novel Diselenide-Linked Porphyrin Dimers under Phase-Transfer Catalysis Condition and Their Interactions with DNA

2009 ◽  
Vol 6 (7) ◽  
pp. 1131-1143 ◽  
Author(s):  
Zhi Xue ◽  
Daniel Wei-Jing Kwong ◽  
Ling-Wei Xue ◽  
Qing Liu ◽  
An-Xin Hou ◽  
...  
Keyword(s):  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Catalysis Condition ◽  
Porphyrin Dimers

scholarly journals Microwave-Assisted Improved Regioselective Synthesis of 12H-Benzopyrano[3,2-c][1]benzopyran-5-ones by Radical Cyclisation

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Pradipta Kumar Basu ◽  
Amrita Ghosh
Keyword(s):  
Microwave Irradiation ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Benzyl Bromide ◽  
Catalytic Amount ◽  
Ammonium Bromide ◽  
Catalysis Condition ◽  
Microwave Assisted ◽  
Tributyltin Hydride ◽  
Tetrabutyl Ammonium

Two new effective methodologies have been adopted for the preparation of 4-(2′-bromobenzyloxy)benzopyran-7-ones 3(a–h). In the first methodology, 4-hydroxy[1]benzopyran-2-ones 1(a–d) was alkylated with 2-bromobenzyl bromide 2a or 2-bromo-5-methoxy benzyl bromide 2b under phase transfer catalysis condition using lithium hydroxide/tetrabutyl ammonium bromide in N,N-dimethylformamide at 40–50°C and in the second method the microwave irradiation protocol has been exploited by simply mixing of 4-hydroxy[1]benzopyran-2-ones 1(a–d) with 25% excess of 2-bromobenzyl bromide 2a or 2-bromo-5-methoxy benzyl bromide 2b. A catalytic amount of TBAB and potassium carbonate were added and irradiated in an open Erlenmeyer flask in a microwave oven for 4–10 min. The tributyltin-hydride-mediated radical cyclisation of 3(a–h) was carried out under microwave irradiation to generate 12H-benzopyrano[3,2-c][1]benzopyran-5-ones 4(a–h) in 78–88% yield and in this technique yields were significantly improved and reaction time was shortened compared to the previously reported conventional radical cyclisation method.

scholarly journals Oxidation of Cyclohexanol and Cyclohexanone by Monochromate Ions in Organic Solvents and on Solvent Free Microwave Irradiation under Phase Transfer Catalysis - A Comparative Study

2021 ◽  
Vol 33 (9) ◽  
pp. 2033-2037
Author(s):  
P. Bashpa ◽  
P. Rajendran ◽  
K. Bijudas
Keyword(s):  
Microwave Irradiation ◽  
Organic Phase ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Mineral Acid ◽  
Solvent Free ◽  
High Yield ◽  
Catalysis Condition ◽  
Solvent Free Condition ◽  
Spectral Technique

Oxidation of cyclohexanol and cyclohexanone were carried out by acidified monochromate ions in ethyl acetate and toluene under phase transfer catalysis and also in solvent free condition under microwave irradiation. The extraction of monochromate ions from aqueous medium to organic phase was carried by employing various phase transfer catalysts in the presence of mineral acids. The effect of [catalyst] and [mineral acid] on extraction of monochromate from aqueous phase to organic phase was also studied. The product obtained, namely adipic acid obtained with both reactants was characterized by its melting point and infrared spectral technique. The reaction was over within 15 min with more than 85% yield at a temperature of 323 K under microwave irradiation where as it gave around 70% yield at 353 K within 150 min under phase transfer catalysis condition. The enhanced reaction rate and high yield of product substantiate the application of phase transfer catalytic technique under microwave irradiation for organic synthesis. A suitable mechanism for the oxidation of substrates by monochromate under phase transfer catalysis is also suggested.

scholarly journals Ultrasonically Promoted Synthesis of Ethyl 2-(naphthalen-2-yloxy)acetate in Solid-Liquid Heterogeneous Phase Transfer Catalysis Condition

2016 ◽  
Vol 11 (3) ◽  
pp. 273 ◽  
Author(s):  
Pachaiyappan Abimannan ◽  
Venugopal Rajendran
Keyword(s):  
Rate Constant ◽  
Quaternary Ammonium ◽  
Apparent Rate Constant ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Tetrabutylammonium Bromide ◽  
Phase Reaction ◽  
Catalysis Condition ◽  
Heterogeneous Phase ◽  
Solid Liquid

<p>In this paper, the synthesis of ethyl 2-(naphthalen-2-yloxy)acetate from β-naphthol and ethyl 2-bromoacetate under ultrasound and catalyzed by quaternary ammonium salt in solid-liquid heterogeneous condition was described. Trace amount of water play a major role in this solid-liquid reaction. The reaction follows pseudo first order rate law. The apparent rate constant of the organic phase reaction was obtained form the experimental data. The combination of small amount of tetrabutylammonium bromide (TBAB) and ultrasound (k<sub>app</sub> = 25.22×10<sup>-3 </sup>min<sup>-1</sup>) shows several fold enhanced rate of the reaction than the conventional operation (k<sub>app</sub> = 6.42×10<sup>-3 </sup>min<sup>-1 </sup>for TBAB only).  The rate constant increases (0.05 to 0.3 g) with increase in the concentration of catalyst (from k<sub>app</sub> = 10.12×10<sup>-3 </sup>min<sup>-1 </sup>to k<sub>app</sub> = 34.46×10<sup>-3 </sup>min<sup>-1</sup>). The other kinetic effects such as, effect of agitation speed, kind of frequency of ultrasound, kind of various quantity of K<sub>2</sub>CO<sub>3</sub>, quantity of water, temperature, different quaternary ammonium salts, solvents and volume of organic solvents on the conversion of ethyl 2-bromoacetate  and apparent rate constant were investigated in detail and rational explanations are provided. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 4<sup>th</sup> November 2015; Revised: 13<sup>rd</sup> January 2016; Accepted: 16<sup>th</sup> January 2016</em></p><p><strong>How to Cite:</strong> Abimannan, P., Rajendran, V. (2016). Ultrasonically Promoted Synthesis of Ethyl 2-(naphthalen-2-yloxy)acetate in Solid-Liquid Heterogeneous Phase Transfer Catalysis Condition. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (3): 273-283 (doi:10.9767/bcrec.11.3.567.273-283)</p><p><strong>Permalink/DOI:</strong><a href="http://doi.org/10.9767/bcrec.11.3.567.273-283"> http://doi.org/10.9767/bcrec.11.3.567.273-283</a></p>

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