scholarly journals Microwave-assisted hydrolysis of biomass over activated carbon supported polyoxometalates

RSC Advances ◽  
2017 ◽  
Vol 7 (20) ◽  
pp. 12346-12350 ◽  
Author(s):  
S. Tsubaki ◽  
K. Oono ◽  
A. Onda ◽  
T. Ueda ◽  
T. Mitani ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Microwave Irradiation ◽  
Microwave Assisted ◽  
Hydrolysis Of

Activated carbon supported polyoxometalates (AC-POMs) were used for acceleration of hydrolysis of biomass under microwave irradiation.

scholarly journals Microwave-assisted Acid Hydrolysis of Starch Polymer in Cassava Pulp in the Presence of Activated Carbon

2012 ◽  
Vol 4 ◽  
pp. 238-244 ◽  
Author(s):  
E. Hermiati ◽  
D. Mangunwidjaja ◽  
T.C. Sunarti ◽  
O. Suparno ◽  
B. Prasetya
Keyword(s):  
Activated Carbon ◽  
Acid Hydrolysis ◽  
Microwave Assisted ◽  
Cassava Pulp ◽  
Hydrolysis Of

Microwave Assisted Synthesis of Isoquercitrin Using Enzymatic Hydrolysis of Rutin

2014 ◽  
Vol 1033-1034 ◽  
pp. 311-314 ◽  
Author(s):  
Jun Wang ◽  
Guo Xia Sun ◽  
An Gong ◽  
Xiang Yang Wu
Keyword(s):  
Reaction Time ◽  
Enzymatic Hydrolysis ◽  
Microwave Irradiation ◽  
Microwave Assisted Synthesis ◽  
Rapid Synthesis ◽  
Reaction Efficiency ◽  
Microwave Assisted ◽  
Hydrolysis Of

A novel and rapid synthesis of isoquercitrin using enzymatic hydrolysis of rutin under microwave irradiation was investigated. In the [Bmim][BF4]-buffer (pH 9.0) system under microwave irradiation, rutin conversion, isoquercitrin yield and quercetin yield were 89.18%, 84.74% and 2.79%, respectively, in conditions of 5 min and 30 °C. The preparation cost of isoquercitrin was significantly reduced by decreasing reaction time (from 10 h to 5 min) and increasing reaction efficiency (by 120 times).

Improvement of microwave-assisted hydrolysis of cassava pulp and tapioca flour by addition of activated carbon

2012 ◽  
Vol 87 (1) ◽  
pp. 939-942 ◽  
Author(s):  
Euis Hermiati ◽  
Jun-ichi Azuma ◽  
Shuntaro Tsubaki ◽  
Djumali Mangunwidjaja ◽  
Titi C. Sunarti ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Microwave Assisted ◽  
Cassava Pulp ◽  
Tapioca Flour ◽  
Hydrolysis Of

Microwave-assisted enzymatic hydrolysis of starch

2009 ◽  
Author(s):  
Marcin Lukasiewicz ◽  
Anna Osowiec ◽  
Magdalena Marciniak
Keyword(s):  
Enzymatic Hydrolysis ◽  
Microwave Assisted ◽  
Hydrolysis Of

Regioselective Synthesis of Potent 4,5,6,7-Tetrahydroindazole Derivatives via Microwave-assisted Vilsmeier-Haack Reaction and their Antioxidant Activity Evaluation

2019 ◽  
Vol 16 (3) ◽  
pp. 194-201 ◽  
Author(s):  
Renu Bala ◽  
Vandana Devi ◽  
Pratibha Singh ◽  
Navjot Kaur ◽  
Pawandeep Kaur ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Microwave Irradiation ◽  
Biological Activities ◽  
Reaction Times ◽  
Conventional Heating ◽  
High Chemical ◽  
Microwave Assisted ◽  
Work Up ◽  
Active Methylene ◽  
By Products

Background: Tetrahydroindazole, a member of the fused-pyrazole system, is a least studied class of heterocyclic compounds owing to its scarcity in nature. However, a large number of synthetically prepared tetrahydroindazoles are known to show a variety of biological activities such as interleukin- 2 inducible T-Cell kinase inhibitors, AMPA receptor positive allosteric modulators, antitumor, antituberculosis, anti-inflammatory and antimicrobial activities. Vilsmeier-Haack reaction is one of the most important chemical reactions used for formylation of electron rich arenes. Even though Vilsmeier- Haack reaction was studied on a wide variety of hydrazones derived from active methylene compounds, literature lacks the examples of the use of 4-substituted cyclohexanones as a substrate for the synthesis of 4,5,6,7-tetrahydroindazoles. The study of the reaction of Vilsmeier-Haack reagent with hydrazones derived from cyclic keto compounds having active methylene has been considered the interested topic of investigation. In the present study, ethyl cyclohexanone-4-carboxylate was treated with one equivalent of various hydrazines for two hours and the resulted hydrazones were further treated with an OPC-VH reagent (Vilsmeier-Haack reagent isolated from phthaloyl dichloride and N,Ndimethylformamide) afforded 4,5,6,7-tetrahydroindazoles in excellent yields. The synthesized compounds 4a-f and 5a-f were screened for their antioxidant activities using the DPPH radical scavenging assay. The target compounds were synthesized regioselectively using 4+1 approach in excellent yields. A number of experiments using both conventional heating as well as microwave irradiation methods were tried and on comparison, microwave irradiation method was found excellent in terms of easy work up, high chemical yields, shortened reaction times, clean and, no by-products formation. Some of the synthesized compounds showed significant antioxidant activity. The microwave assisted synthesis of 4,5,6,7-tetrahydroindazoles from ethyl cyclohexanone-4-carboxylate has been reported under mild conditions in excellent yield. Easy work up, high chemical yield, shortened reaction times, clean and no by-products formation are the major advantages of this protocol. These advantages may make this method useful for chemists who are interested in developing novel 4,5,6,7-tetrahydroindazole based drugs.

Microwave-assisted Synthesis of Benzoxazoles Derivatives

2020 ◽  
Vol 7 (3) ◽  
pp. 183-195
Author(s):  
Musa Özil ◽  
Emre Menteşe
Keyword(s):  
Microwave Irradiation ◽  
Reaction Medium ◽  
Pharmaceutical Chemistry ◽  
Conventional Heating ◽  
High Yield ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Optical Brighteners ◽  
Chemistry Research ◽  
Extensive Class

Background: Benzoxazole, containing a 1,3-oxazole system fused with a benzene ring, has a profound effect on medicinal chemistry research owing to its important pharmacological activities. On the other hand, the benzoxazole derivative has exhibited important properties in material science. Especially in recent years, microwave-assisted synthesis is a technique that can be used to increase diversity and quick research in modern chemistry. The utilization of microwave irradiation is beneficial for the synthesis of benzoxazole in recent years. In this focused review, we provide a metaanalysis of studies on benzoxazole in different reaction conditions, catalysts, and starting materials by microwave technique so far, which is different from conventional heating. Methods: Synthesis of different kind of benzoxazole derivatives have been carried out by microwave irradiation. The most used method to obtain benzoxazoles is the condensation of 2-aminophenol or its derivatives with aldehydes, carboxylic acids, nitriles, isocyanates, and aliphatic amines. Results: Benzoxazole system and its derivatives have exhibited a broad range of pharmacological properties. Thus, many scientists have remarked on the importance of the synthesis of different benzoxazole derivatives. Conventional heating is a relatively inefficient and slow method to convey energy in orientation to the reaction medium. However, the microwave-assisted heating technique is a more effective interior heating by straight coupling of microwave energy with the molecules. Conclusion: In this review, different studies were presented on the recent details accessible in the microwave- assisted techniques on the synthesis of the benzoxazole ring. It presents all examples of such compounds that have been reported from 1996 to the present. Benzoxazoles showed an extensive class of chemical substances not only in pharmaceutical chemistry but also in dyestuff, polymer industries, agrochemical, and optical brighteners. Thus the development of fast and efficient achievement of benzoxazoles with a diversity of substituents in high yield is getting more noteworthy. As shown in this review, microwave-assisted synthesis of benzoxazoles is a very effective and useful technique.

scholarly journals Pretreatment of Switchgrass for Production of Glucose via Sulfonic Acid-Impregnated Activated Carbon

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 504
Author(s):  
Yane Ansanay ◽  
Praveen Kolar ◽  
Ratna Sharma-Shivappa ◽  
Jay Cheng ◽  
Consuelo Arellano
Keyword(s):  
Activated Carbon ◽  
Sulfonic Acid ◽  
Solid Acid ◽  
Methanesulfonic Acid ◽  
Biofuel Production ◽  
Acid Catalysts ◽  
Effects Of Temperature ◽  
Carbon Catalysts ◽  
Hydrolysis Of

In the present research, activated carbon-supported sulfonic acid catalysts were synthesized and tested as pretreatment agents for the conversion of switchgrass into glucose. The catalysts were synthesized by reacting sulfuric acid, methanesulfonic acid, and p-toluenesulfonic acid with activated carbon. The characterization of catalysts suggested an increase in surface acidities, while surface area and pore volumes decreased because of sulfonation. Batch experiments were performed in 125 mL serum bottles to investigate the effects of temperature (30, 60, and 90 °C), reaction time (90 and 120 min) on the yields of glucose. Enzymatic hydrolysis of pretreated switchgrass using Ctec2 yielded up to 57.13% glucose. Durability tests indicated that sulfonic solid-impregnated carbon catalysts were able to maintain activity even after three cycles. From the results obtained, the solid acid catalysts appear to serve as effective pretreatment agents and can potentially reduce the use of conventional liquid acids and bases in biomass-into-biofuel production.

scholarly journals Microwave-Assisted Asinger Synthesis of Thiazolines

2020 ◽  
Vol 3 (1) ◽  
pp. 27
Author(s):  
Raúl Eduardo Gordillo-Cruz ◽  
Liliana Gonzalez-Reyes ◽  
Milton Coporo-Reyes ◽  
Nieves Zavala-Segovia ◽  
Bernardo A. Frontana-Uribe ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Reaction Times ◽  
Reaction Conditions ◽  
Microwave Assisted

An array of 2,4-disubstituted thiazolines was obtained through Asinger reaction approach from the straightforward treatment of diverse aldehydes/ketones with 1-mercaptopropan-2-one, in the presence of NH3 assisted by microwave irradiation, displaying similar and sometimes higher yields, as well as shorter reaction times that traditional Asinger reaction conditions at room and lower temperatures.

scholarly journals Microwave-assisted Oxidation of Alcohols by Pyridinium Chlorochromate

1999 ◽  
Vol 23 (2) ◽  
pp. 118-119
Author(s):  
Vaishali Chakraborty ◽  
Manobjyoti Bordoloi
Keyword(s):  
Microwave Irradiation ◽  
Pyridinium Chlorochromate ◽  
Microwave Assisted ◽  
Oxidation Of Alcohols

An efficient and mild methodology for the oxidation of alcohols to the corresponding carbonyl functions is described using pyridinium chlorochromate under microwave irradiation.

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