A Rapid and High-yield Synthesis of Aryloxyacetyl Hydrazides under Microwave Irradiation and with Phase Transfer Catalysis

2005 ◽  
Vol 2005 (7) ◽  
pp. 432-433 ◽  
Author(s):  
Tai-Bao Wei ◽  
Hong Liu ◽  
Man-Lin Li ◽  
You-Ming Zhang

A series of aryloxyacetyl hydrazides 4a–l were synthesised under microwave irradiation and phase transfer catalysis conditions. By the optimisation of the reaction conditions, a rapid, high-yield and efficient method for the preparation of aryloxyacetyl hydrazide was given.

2021 ◽  
Vol 33 (9) ◽  
pp. 2033-2037
Author(s):  
P. Bashpa ◽  
P. Rajendran ◽  
K. Bijudas

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.


2005 ◽  
Vol 35 (13) ◽  
pp. 1759-1764 ◽  
Author(s):  
Tai‐Bao Wei ◽  
Hong Liu ◽  
Man‐Lin Li ◽  
You‐Ming Zhang

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Pradipta Kumar Basu ◽  
Amrita Ghosh

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.


2013 ◽  
Vol 690-693 ◽  
pp. 1061-1064 ◽  
Author(s):  
Lu Jing ◽  
Guo Qin Liu ◽  
Xin Qi Liu ◽  
Xue De Wang

In the system of heteropoly acid [π-C5H5NC16H33]3[PO4(WO3)4], H2O2 (30 %, w/w), polyethylene glycol, 1,2-dichloroethane, soybean oil under went epoxidation reaction smoothly via reaction-controlled phase transfer catalysis. Effects of the amount of interfacial active agent, H2O2, catalyst and reaction time were investigated and the optimized reaction conditions were as follows: 10 g of soybean oil, 0.3 g of [π-C5H5NC16H33]3[PO4 (WO3)4],8 ml of H2O2 (30 %, w/w), 5.0 ml of PEG, 30 g of 1,2-dichloroethane, and the reaction temperature was 65 °C and reaction time was 3.5-4.0 h. Under these optimized conditions, an epoxy value of 6.30 % and a yield of 90 % were obtained. Hence, it is an environmental-friendly and effective way to synthesize epoxidized soybean oil.


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