Pub Date : 2023-05-16DOI: 10.2174/2213335610666230516165046
D. Sengupta, Ranjan Kumar Das, Debdulal Sharma, S. Paul
Microwave synthesis has developed as a powerful tool for the cost-effective and greener synthesis of organic molecules, including quinazolines. Irradiation with microwave leads to the excitation of molecules and equitable distribution of thermal energy in a much shorter time than conventional synthesis. This results in shorter reaction time and, more often than not, higher efficiency. The primary objective of the work presented in this article was to prepare hydrazine hydrate or thiourea derivative of quinazolines through microwave synthesis as small-molecule scaffolds for further need-based functionalisation, isolation, and characterisation. We, herein, report the synthesis of two quinazolinone derivatives of thiourea and hydrazine, 3-amino-2-phenylquinazolin-4(3H)-one (QH) and 4-oxo-2-phenylquinazoline-3(4H)-carbothioamide (QTh), respectively. A multi-step synthetic strategy starting from anthranilic acid was employed to synthesise the small molecule quinazolinones 3-amino-2-phenylquinazolin-4(3H)-one (QH) and 4-oxo-2-phenylquinazoline-3(4H)-carbothioamide (QTh). The compounds were synthesised by reacting hydrazine and thiourea with 2-benzamidobenzoyl chloride in DMF under microwave irradiation (800 W at 135 °C for 4 min) in the presence of potassium carbonate. The acid chloride was prepared by chlorination of 2-benzamidobenzoic acid, which in turn was synthesised from anthranilic acid by benzoylation. This method is an efficient alternative approach to synthesising quinazolinones from benzoxazin-4-ones. We have successfully synthesised, isolated, and characterised the quinazolinone derivative QH (yield: 81%) and QTh (yield: 85%). The structures of the compounds were established through spectroscopic techniques. Theoretical optimisation of the structures was also achieved using DFT. The HOMO-LUMO difference for QH and QTh was calculated to be 4.60 and 4.47 eV, respectively. The reported protocol is advantageous over conventional methods of quinazoline synthesis from benzoxazin-4-ones. The time required for the reaction is much less (4 min) as compared to the usual requirements of reflux (> 4 h); the higher energy gap of QTh indicates greater stability than that of QH. Keywords: 3-amino-2-phenylquinazolin-4(3H)-one (QH), 4-oxo-2-phenylquinazoline-3(4H)-carbothioamide (QTh), HOMO-LUMO, DMF, microwave irradiation.
{"title":"Microwave-assisted Synthesis of 3-amino-2-phenylquinazolin-4(3H)-one (QH) and 4-oxo-2-phenylquinazoline-3(4H)-carbothioamide (QTh)","authors":"D. Sengupta, Ranjan Kumar Das, Debdulal Sharma, S. Paul","doi":"10.2174/2213335610666230516165046","DOIUrl":"https://doi.org/10.2174/2213335610666230516165046","url":null,"abstract":"\u0000\u0000Microwave synthesis has developed as a powerful tool for the cost-effective and greener synthesis of organic molecules, including quinazolines. Irradiation with microwave leads to the excitation of molecules and equitable distribution of thermal energy in a much shorter time than conventional synthesis. This results in shorter reaction time and, more often than not, higher efficiency.\u0000\u0000\u0000\u0000The primary objective of the work presented in this article was to prepare hydrazine hydrate or thiourea derivative of quinazolines through microwave synthesis as small-molecule scaffolds for further need-based functionalisation, isolation, and characterisation. We, herein, report the synthesis of two quinazolinone derivatives of thiourea and hydrazine, 3-amino-2-phenylquinazolin-4(3H)-one (QH) and 4-oxo-2-phenylquinazoline-3(4H)-carbothioamide (QTh), respectively.\u0000\u0000\u0000\u0000A multi-step synthetic strategy starting from anthranilic acid was employed to synthesise the small molecule quinazolinones 3-amino-2-phenylquinazolin-4(3H)-one (QH) and 4-oxo-2-phenylquinazoline-3(4H)-carbothioamide (QTh). The compounds were synthesised by reacting hydrazine and thiourea with 2-benzamidobenzoyl chloride in DMF under microwave irradiation (800 W at 135 °C for 4 min) in the presence of potassium carbonate. The acid chloride was prepared by chlorination of 2-benzamidobenzoic acid, which in turn was synthesised from anthranilic acid by benzoylation. This method is an efficient alternative approach to synthesising quinazolinones from benzoxazin-4-ones.\u0000\u0000\u0000\u0000We have successfully synthesised, isolated, and characterised the quinazolinone derivative QH (yield: 81%) and QTh (yield: 85%). The structures of the compounds were established through spectroscopic techniques. Theoretical optimisation of the structures was also achieved using DFT. The HOMO-LUMO difference for QH and QTh was calculated to be 4.60 and 4.47 eV, respectively.\u0000\u0000\u0000\u0000The reported protocol is advantageous over conventional methods of quinazoline synthesis from benzoxazin-4-ones. The time required for the reaction is much less (4 min) as compared to the usual requirements of reflux (> 4 h); the higher energy gap of QTh indicates greater stability than that of QH.\u0000Keywords: 3-amino-2-phenylquinazolin-4(3H)-one (QH), 4-oxo-2-phenylquinazoline-3(4H)-carbothioamide (QTh), HOMO-LUMO, DMF, microwave irradiation.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47817560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-20DOI: 10.2174/2213335610666230420085314
Deepali Amol Bansode, Tanvi Goel, Raihan Arikkattel Abdu, S. Dev
Nitrogen containing heterocycles such as azoles have gained popularity in medicinal chemistry research due to their versatile pharmacological activities. Imidazole’s are one such class of adaptable compounds. The aim of the study was to explore pharmacological activities of 2,4,5-trisubstituted imidazole’s and also to develop a novel method of synthesis using microwave chemistry. In the present study, the in-silico studies of 2,4,5-trisubstituted imidazole’s was carried out to predict their anti-leishmanial as well as COX-2 inhibitory activity. Although, the results are not satisfactory for the anti-leishmanial activity, the molecules showed comparable docking scores with standard celecoxib for the COX-2 inhibitory activity. Later, the microwave-assisted green synthesis of tri-substituted imidazole’s was attempted using green catalyst and solvent, molecular iodine and ethanol respectively. The synthesised derivatives (TG-1-4) were purified and characterised. The derivatives were subjected to in-vitro COX-2 inhibitory assay, which showed good results. The molecules under study showed exemplary results against COX-2 PDB in molecular docking studies. A novel microwave-irradiation method was developed for the synthesis and also the in-vivo studies carried out for testing COX-2 inhibition was fruitful. the microwave-assisted green synthesis of tri-substituted imidazole’s was attempted using green catalyst and solvent, molecular iodine and ethanol respectively. The synthesised derivatives were purified and characterised. In conclusion, the selected derivatives can be further studied in-vivo to develop new COX-2 inhibitors. -
{"title":"Molecular Docking, Microwave-Assisted Synthesis, Characterization and Pharmacological Evaluation of 2,4,5-trisubstituted Imidazole’s","authors":"Deepali Amol Bansode, Tanvi Goel, Raihan Arikkattel Abdu, S. Dev","doi":"10.2174/2213335610666230420085314","DOIUrl":"https://doi.org/10.2174/2213335610666230420085314","url":null,"abstract":"\u0000\u0000Nitrogen containing heterocycles such as azoles have gained popularity in medicinal chemistry research due to their versatile pharmacological activities. Imidazole’s are one such class of adaptable compounds. The aim of the study was to explore pharmacological activities of 2,4,5-trisubstituted imidazole’s and also to develop a novel method of synthesis using microwave chemistry.\u0000\u0000\u0000\u0000In the present study, the in-silico studies of 2,4,5-trisubstituted imidazole’s was carried out to predict their anti-leishmanial as well as COX-2 inhibitory activity. Although, the results are not satisfactory for the anti-leishmanial activity, the molecules showed comparable docking scores with standard celecoxib for the COX-2 inhibitory activity. Later, the microwave-assisted green synthesis of tri-substituted imidazole’s was attempted using green catalyst and solvent, molecular iodine and ethanol respectively. The synthesised derivatives (TG-1-4) were purified and characterised.\u0000\u0000\u0000\u0000The derivatives were subjected to in-vitro COX-2 inhibitory assay, which showed good results. The molecules under study showed exemplary results against COX-2 PDB in molecular docking studies. A novel microwave-irradiation method was developed for the synthesis and also the in-vivo studies carried out for testing COX-2 inhibition was fruitful.\u0000\u0000\u0000\u0000the microwave-assisted green synthesis of tri-substituted imidazole’s was attempted using green catalyst and solvent, molecular iodine and ethanol respectively. The synthesised derivatives were purified and characterised.\u0000\u0000\u0000\u0000In conclusion, the selected derivatives can be further studied in-vivo to develop new COX-2 inhibitors.\u0000\u0000\u0000\u0000-\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41796507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-30DOI: 10.2174/2213335610666230330164520
In the past few years, using microwave power to heat and wield chemical reactions has become a gradually more popular subject in the scientific community. Microwave-supported organic synthesis is confirmed to be involved in the rapid synthesis of novel compounds with selectivity and enhanced biological activities. Microwave flash heating for chemical synthesis is a spectacular reduction in reaction times, high yield and purity of the products, etc. A catalysis field wherein small organic molecules like L-Proline is an efficiently and selectively catalyze organic transformations. Microwave-assisted L-Proline catalyzed reactions are valuable tools for the making of different acyclic, heterocycles, and carbocyclic scaffolds that signify the main framework of most of the bio-active compounds. The areas of synthetic organic chemistry, microwave irradiation is speedily discarded the conventional heating methods in the world of multicomponent as well as step-wise synthetic chemistry. In this review, we discuss only L-Proline Catalyzed Organic Reactions under microwave activation using modern organic transformations including condensation, addition, asymmetric, multi-components, and other modular reactions.
{"title":"L-Proline Catalyzed Organic Reactions via Microwave-Activation","authors":"","doi":"10.2174/2213335610666230330164520","DOIUrl":"https://doi.org/10.2174/2213335610666230330164520","url":null,"abstract":"\u0000\u0000In the past few years, using microwave power to heat and wield chemical reactions has become a gradually more popular subject in the scientific community. Microwave-supported organic synthesis is confirmed to be involved in the rapid synthesis of novel compounds with selectivity and enhanced biological activities. Microwave flash heating for chemical synthesis is a spectacular reduction in reaction times, high yield and purity of the products, etc. A catalysis field wherein small organic molecules like L-Proline is an efficiently and selectively catalyze organic transformations. Microwave-assisted L-Proline catalyzed reactions are valuable tools for the making of different acyclic, heterocycles, and carbocyclic scaffolds that signify the main framework of most of the bio-active compounds. The areas of synthetic organic chemistry, microwave irradiation is speedily discarded the conventional heating methods in the world of multicomponent as well as step-wise synthetic chemistry. In this review, we discuss only L-Proline Catalyzed Organic Reactions under microwave activation using modern organic transformations including condensation, addition, asymmetric, multi-components, and other modular reactions.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46509965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-23DOI: 10.2174/2213335610666230223100707
Samuel Lalthazuala Rokhum, Supongsenla Ao, Michael VL Chhandama, Hu Li
Limited crude petroleum and growing awareness of fossil fuel depletion have enabled the development of alternative fuels and new energy sources. Biodiesel, also known as fatty acid methyl esters (FAME), has received a lot of attention due to its biodegradability, renewability, cost effective and nontoxicity. The purity of biodiesel production and uniform heating are the major hurdles for large scale biodiesel production. Recent microwave energy-based heating method has proved the potential for cleaner chemical production, short time duration, uniform heating, and purity over conventional heating method. The goal of this review is to discuss the biodiesel production using microwave-assisted heating. The different feedstocks used for biodiesel production, effects of microwave irradiation, factors affecting the rate of microwave-assisted transesterification to produce biodiesel were comprehensively discussed. Microwave irradiation has been compared to other technologies aiming to enhance the efficiency of overall process. The primary knowledge gaps in biodiesel production can be identified based on this research, ensuring the biodiesel industry's long-term sustainability.
{"title":"Microwave-assisted sustainable production of biodiesel: A comprehensive review","authors":"Samuel Lalthazuala Rokhum, Supongsenla Ao, Michael VL Chhandama, Hu Li","doi":"10.2174/2213335610666230223100707","DOIUrl":"https://doi.org/10.2174/2213335610666230223100707","url":null,"abstract":"\u0000\u0000Limited crude petroleum and growing awareness of fossil fuel depletion have enabled the development of alternative fuels and new energy sources. Biodiesel, also known as fatty acid methyl esters (FAME), has received a lot of attention due to its biodegradability, renewability, cost effective and nontoxicity. The purity of biodiesel production and uniform heating are the major hurdles for large scale biodiesel production. Recent microwave energy-based heating method has proved the potential for cleaner chemical production, short time duration, uniform heating, and purity over conventional heating method. The goal of this review is to discuss the biodiesel production using microwave-assisted heating. The different feedstocks used for biodiesel production, effects of microwave irradiation, factors affecting the rate of microwave-assisted transesterification to produce biodiesel were comprehensively discussed. Microwave irradiation has been compared to other technologies aiming to enhance the efficiency of overall process. The primary knowledge gaps in biodiesel production can be identified based on this research, ensuring the biodiesel industry's long-term sustainability.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45827116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-13DOI: 10.2174/2213335610666230213113809
Guangshan Zhang, Menghan Cao, Ke Tian, F. Shi
In previous work, we successfully prepared CuO/Al2O3 catalysts and evaluated their catalytic activity, kinetics and degradation mechanism for Fenton-like oxidation of p-nitrophenol (PNP) under microwave irradiation. However, we did not study the effect of important preparation parameters on the activities of catalysts. (1) The effect of preparation conditions: CuSO4 concentration of the impregnating solution, Al2O3 to CuSO4 solution ratio, type and concentration of precipitant and calcination temperature on the physico-chemical properties and catalytic activity were studied. (2) The catalytic performance of the Fenton-like oxidation reaction of PNP under microwave irradiation was evaluated and correlated with the characterization results. (3) The stability and catalytic mechanism of the catalysts were investigated. (1) The effect of preparation conditions: CuSO4 concentration of impregnating solution, Al2O3 to CuSO4 solution ratio, type and concentration of precipitant and calcination temperature on the physico-chemical properties and catalytic activity were studied. (2) The catalytic performance of the Fenton-like oxidation reaction of PNP under microwave irradiation was evaluated and correlated with the characterization results.(3) The stability and catalytic mechanism of the catalysts were investigated. The CuO/Al2O3 catalyst was prepared by the impregnation deposition method. The 20 g pretreated Al2O3 particles were immersed in 0.6 mol/L Cu (NO3)2 solution and 0.4 mol/L NaOH solution for 24 h before and after. After cleaning and drying, the samples were calcined in an air muffle furnace for 4 h at a certain temperature to obtain CuO/Al2O3 catalyst. Then the catalyst was characterized and catalyzed. The CuO/Al2O3 catalyst was prepared by impregnation deposition method. The 20 g pretreated Al2O3 particles were immersed in 0.6 mol/L Cu (NO3)2 solution and 0.4 mol/L NaOH solution for 24 hours before and after. After cleaning and drying, the samples were calcined in an air muffle furnace for 4 hours at a certain temperature to obtain CuO/Al2O3 catalyst. Then the catalyst was characterized and catalyzed. XRD, BET and FESEM results have demonstrated that the catalyst claimed at 300 and 350 ℃ showed a smaller size, a higher specific surface area and a better distribution of the CuO species than their counterparts prepared at higher calcination temperatures. The CuO/Al2O3 catalyst claimed at 300 and 350 ℃ also showed higher removal efficiencies for PNP than other catalysts prepared at higher calcination temperatures. XRD, BET and FESEM results have demonstrated that the catalyst claimed at 300 and 350 ℃ showed a smaller size, a higher specific surface area and a better distribution of the CuO species than their counterparts prepared at higher calcination temperatures. the CuO/Al2O3 catalyst claimed at 300 and 350 ℃ also showed higher removal efficiencies for PNP than other catalysts prepared at higher calcination temperatures. I
在之前的工作中，我们成功制备了CuO/Al2O3催化剂，并在微波照射下对Fenton-like氧化对硝基苯酚(PNP)的催化活性、动力学和降解机理进行了评价。(1)研究了浸渍液中CuSO4浓度、Al2O3与CuSO4溶液比例、沉淀剂种类和浓度、煅烧温度等制备条件对催化剂理化性质和催化活性的影响。(2)评价微波辐照下PNP类fenton氧化反应的催化性能，并与表征结果进行关联。(1)研究了浸渍液CuSO4浓度、Al2O3与CuSO4溶液比例、沉淀剂种类和浓度、煅烧温度等制备条件对催化剂理化性能和催化活性的影响。(2)评价了微波辐照下PNP类fenton氧化反应的催化性能，并与表征结果进行了关联。(3)考察了催化剂的稳定性和催化机理。采用浸渍沉淀法制备CuO/Al2O3催化剂。将20 g预处理后的Al2O3颗粒分别浸入0.6 mol/L Cu (NO3)2溶液和0.4 mol/L NaOH溶液中浸泡24 h。样品清洗干燥后，在空气马弗炉中在一定温度下煅烧4 h，得到CuO/Al2O3催化剂。然后对催化剂进行表征和催化。采用浸渍沉积法制备CuO/Al2O3催化剂。将20 g预处理后的Al2O3颗粒分别浸入0.6 mol/L Cu (NO3)2溶液和0.4 mol/L NaOH溶液中24小时。样品清洗干燥后，在空气马弗炉中在一定温度下煅烧4小时，得到CuO/Al2O3催化剂。然后对催化剂进行表征和催化。XRD、BET和FESEM结果表明，在300℃和350℃制备的催化剂比在较高煅烧温度下制备的催化剂具有更小的尺寸、更高的比表面积和更好的CuO组分分布。在300℃和350℃下制备的CuO/Al2O3催化剂对PNP的去除率也高于在较高焙烧温度下制备的其他催化剂。XRD、BET和FESEM结果表明，在300℃和350℃制备的催化剂比在较高煅烧温度下制备的催化剂具有更小的尺寸、更高的比表面积和更好的CuO组分分布。在300℃和350℃下制备的CuO/Al2O3催化剂对PNP的去除率也高于在较高焙烧温度下制备的其他催化剂。结果表明，在350℃煅烧温度下制备的催化剂比表面积大，CuO粒径小，CuO粒径分布均匀，具有较好的催化活性，稳定性和可重复使用性较好。此外，催化剂的XPS结果显示，微波增强Fenton-like反应后Isat/Ip比降低，证实CuO在一定程度上被还原为Cu2O。
{"title":"Effect of Synthesis Conditions on the Catalytic Performances of CuO/Al2O3 in Microwave-enhanced Fenton-like System","authors":"Guangshan Zhang, Menghan Cao, Ke Tian, F. Shi","doi":"10.2174/2213335610666230213113809","DOIUrl":"https://doi.org/10.2174/2213335610666230213113809","url":null,"abstract":"\u0000\u0000In previous work, we successfully prepared CuO/Al2O3 catalysts and evaluated their catalytic activity, kinetics and degradation mechanism for Fenton-like oxidation of p-nitrophenol (PNP) under microwave irradiation. However, we did not study the effect of important preparation parameters on the activities of catalysts.\u0000\u0000\u0000\u0000(1) The effect of preparation conditions: CuSO4 concentration of the impregnating solution, Al2O3 to CuSO4 solution ratio, type and concentration of precipitant and calcination temperature on the physico-chemical properties and catalytic activity were studied. (2) The catalytic performance of the Fenton-like oxidation reaction of PNP under microwave irradiation was evaluated and correlated with the characterization results. (3) The stability and catalytic mechanism of the catalysts were investigated.\u0000\u0000\u0000\u0000(1) The effect of preparation conditions: CuSO4 concentration of impregnating solution, Al2O3 to CuSO4 solution ratio, type and concentration of precipitant and calcination temperature on the physico-chemical properties and catalytic activity were studied. (2) The catalytic performance of the Fenton-like oxidation reaction of PNP under microwave irradiation was evaluated and correlated with the characterization results.(3) The stability and catalytic mechanism of the catalysts were investigated.\u0000\u0000\u0000\u0000The CuO/Al2O3 catalyst was prepared by the impregnation deposition method. The 20 g pretreated Al2O3 particles were immersed in 0.6 mol/L Cu (NO3)2 solution and 0.4 mol/L NaOH solution for 24 h before and after. After cleaning and drying, the samples were calcined in an air muffle furnace for 4 h at a certain temperature to obtain CuO/Al2O3 catalyst. Then the catalyst was characterized and catalyzed.\u0000\u0000\u0000\u0000The CuO/Al2O3 catalyst was prepared by impregnation deposition method. The 20 g pretreated Al2O3 particles were immersed in 0.6 mol/L Cu (NO3)2 solution and 0.4 mol/L NaOH solution for 24 hours before and after. After cleaning and drying, the samples were calcined in an air muffle furnace for 4 hours at a certain temperature to obtain CuO/Al2O3 catalyst. Then the catalyst was characterized and catalyzed.\u0000\u0000\u0000\u0000XRD, BET and FESEM results have demonstrated that the catalyst claimed at 300 and 350 ℃ showed a smaller size, a higher specific surface area and a better distribution of the CuO species than their counterparts prepared at higher calcination temperatures. The CuO/Al2O3 catalyst claimed at 300 and 350 ℃ also showed higher removal efficiencies for PNP than other catalysts prepared at higher calcination temperatures.\u0000\u0000\u0000\u0000XRD, BET and FESEM results have demonstrated that the catalyst claimed at 300 and 350 ℃ showed a smaller size, a higher specific surface area and a better distribution of the CuO species than their counterparts prepared at higher calcination temperatures. the CuO/Al2O3 catalyst claimed at 300 and 350 ℃ also showed higher removal efficiencies for PNP than other catalysts prepared at higher calcination temperatures.\u0000\u0000\u0000\u0000I","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48681301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-05DOI: 10.2174/2213335610666230105154742
Deepali Bansode, Tanvi Goel, Naman Jain
The organic and peptide synthesis, various nanotechnology, and biochemistry processes are being carried out using microwave irradiation. The use of microwaves for synthesis has increased in the past two decades. The microwave offers several advantages such as ease of handling, lesser reaction times, quality of the product, and eco-friendly, which is green. The conventional method of synthesis, on the other hand, requires a longer time, is difficult to handle and maintenance of temperature is also difficult. The use of microwave-assisted reactions over conventional methods is advantageous in medicinal chemistry research as they will be less time-consuming and crucial in drug discovery and development. On the other side, they might not work in bulk synthesis due to their limited capacity for loading the reaction mixture. The present work aims to compare reaction time, temperature and percentage of yield of the microwave-assisted synthesis method against the conventional method. A novel, simple, and green method was developed for the synthesis of tri-substituted imidazoles by microwave irradiation. Both derivatives from conventional and microwave-assisted synthesis were characterized by IR spectroscopy, Mass spectrometry, and 1H-NMR spectroscopy. The same derivatives were also synthesized by the conventional method for comparison. A comparison of both methods was made by comparing the reaction time and the percentage yield. It was found that microwave-assisted reactions produced greater yield in the minimal time, though at different reaction temperatures. It can be concluded from the present comparison study that the use of the microwave for synthesis provides numerous advantages; thus, newer molecules are developed quickly anthat are developed quickly. To further proceed in this direction and to produce evidences, synthesis of more derivatives may be required. The only disadvantage is that it cannot be used for bulk synthesis of the compounds.
{"title":"Conventional vs. microwave-assisted synthesis: A comparative study on the synthesis of tri-substituted imidazoles","authors":"Deepali Bansode, Tanvi Goel, Naman Jain","doi":"10.2174/2213335610666230105154742","DOIUrl":"https://doi.org/10.2174/2213335610666230105154742","url":null,"abstract":"\u0000\u0000The organic and peptide synthesis, various nanotechnology, and biochemistry processes are being carried out using microwave irradiation. The use of microwaves for synthesis has increased in the past two decades. The microwave offers several advantages such as ease of handling, lesser reaction times, quality of the product, and eco-friendly, which is green. The conventional method of synthesis, on the other hand, requires a longer time, is difficult to handle and maintenance of temperature is also difficult. The use of microwave-assisted reactions over conventional methods is advantageous in medicinal chemistry research as they will be less time-consuming and crucial in drug discovery and development. On the other side, they might not work in bulk synthesis due to their limited capacity for loading the reaction mixture.\u0000\u0000\u0000\u0000The present work aims to compare reaction time, temperature and percentage of yield of the microwave-assisted synthesis method against the conventional method.\u0000\u0000\u0000\u0000A novel, simple, and green method was developed for the synthesis of tri-substituted imidazoles by microwave irradiation. Both derivatives from conventional and microwave-assisted synthesis were characterized by IR spectroscopy, Mass spectrometry, and 1H-NMR spectroscopy. The same derivatives were also synthesized by the conventional method for comparison.\u0000\u0000\u0000\u0000A comparison of both methods was made by comparing the reaction time and the percentage yield. It was found that microwave-assisted reactions produced greater yield in the minimal time, though at different reaction temperatures.\u0000\u0000\u0000\u0000It can be concluded from the present comparison study that the use of the microwave for synthesis provides numerous advantages; thus, newer molecules are developed quickly anthat are developed quickly. To further proceed in this direction and to produce evidences, synthesis of more derivatives may be required. The only disadvantage is that it cannot be used for bulk synthesis of the compounds.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46444255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-05DOI: 10.2174/2213335610666230105162405
G. Keglevich
{"title":"The Application of Microwaves in the Esterification of P-acids","authors":"G. Keglevich","doi":"10.2174/2213335610666230105162405","DOIUrl":"https://doi.org/10.2174/2213335610666230105162405","url":null,"abstract":"<jats:sec>\u0000<jats:title />\u0000<jats:p />\u0000</jats:sec>","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46292926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-26DOI: 10.2174/2213335610666221226143419
D. Liu, Jinjia Du, Qingqing Dai, Junwen Zhou
Manganese is a vital metal resource, and increased consumption of manganese is leading to the shortage of high-grade manganese ore resources. However, a large number of low-grade manganese ore resources ((Mn<30%) accounts for about 60% of the total manganese resources) have not been effectively utilized because of the lack of efficient industrial utilization methods. Researching new technologies for reducing low-grade pyrolusite is an urgent problem to be solved. Microwave is an effective and environmentally friendly heat source widely used in mining, metallurgy, and chemistry. Different substances have different dielectric constants. The difference in dielectric constant affects the absorption rate of substances, resulting in different heating rates for different substances when heated by microwaves. Microwave is widely used in the metal smelting process because of its unique heating method. So far, few works have been done to verify that microwave heating can effectively promote the reduction of pyrolusite. This article summarizes some current methods of reducing low-grade pyrolusite and compares them with the method of reducing pyrolusite by microwave heating. In addition, this article introduces the principle of microwave-enhanced reduction of pyrolusite and discusses the opportunities and challenges faced by microwave heating technology in its subsequent development. The aim is to analyze and study the promoting effect of microwave heating technology on the reduction of pyrolusite, further improve the utilization of low-grade pyrolusite, and provide new methods and approaches for the comprehensive utilization of mineral resources and provide assistance in industrial production.
{"title":"Study on microwave-assisted reduction of pyrolusite","authors":"D. Liu, Jinjia Du, Qingqing Dai, Junwen Zhou","doi":"10.2174/2213335610666221226143419","DOIUrl":"https://doi.org/10.2174/2213335610666221226143419","url":null,"abstract":"\u0000\u0000Manganese is a vital metal resource, and increased consumption of manganese is leading to the shortage of high-grade manganese ore resources. However, a large number of low-grade manganese ore resources ((Mn<30%) accounts for about 60% of the total manganese resources) have not been effectively utilized because of the lack of efficient industrial utilization methods. Researching new technologies for reducing low-grade pyrolusite is an urgent problem to be solved. Microwave is an effective and environmentally friendly heat source widely used in mining, metallurgy, and chemistry. Different substances have different dielectric constants. The difference in dielectric constant affects the absorption rate of substances, resulting in different heating rates for different substances when heated by microwaves. Microwave is widely used in the metal smelting process because of its unique heating method. So far, few works have been done to verify that microwave heating can effectively promote the reduction of pyrolusite. This article summarizes some current methods of reducing low-grade pyrolusite and compares them with the method of reducing pyrolusite by microwave heating. In addition, this article introduces the principle of microwave-enhanced reduction of pyrolusite and discusses the opportunities and challenges faced by microwave heating technology in its subsequent development. The aim is to analyze and study the promoting effect of microwave heating technology on the reduction of pyrolusite, further improve the utilization of low-grade pyrolusite, and provide new methods and approaches for the comprehensive utilization of mineral resources and provide assistance in industrial production.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41777562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-08DOI: 10.2174/2213335610666221208163107
B. Török, T. Mooney, Maysa Ilamanova
Using combined microwave-assisted flow chemistry approaches is one of the most active areas of microwave chemistry and green synthesis. Microwave-assisted organic synthesis (MAOS) has contributed significantly to developing green synthetic methods, while flow chemistry applications are quite popular in industrial chemistry. The combination of the two has far-reaching advantages. In early studies, the flow chemistry concept was applied in domestic microwave ovens already indicating strong potential for future applications. The relatively small diameter of the flow reactors can address the limited penetration depth of microwaves, which is a major impediment in large-scale batch reactors. With the commercial availability of dedicated microwave synthesizers with tunable frequencies and better temperature control, the possibilities to apply flow synthesis grew even broader. The developments focus on several issues; the two major ones are the design and application of reactors and catalysts. Common reactor types include microwave-absorbing, such as silicon carbide, and microwave-transparent materials, such as borosilicate glass, quartz, or Teflon, with the catalyst or solvent adjusted accordingly. Several heterogeneous catalysts are considered strong microwave absorbers that can heat the reaction from inside the reactor. Such materials include clays, zeolites, or supported metal catalysts. Here, the major advances in design and applications and the benefits gained will be illustrated by synthesizing fine chemicals, from organic compounds to nanoparticles and new materials.
{"title":"Microwave-Assisted Flow Chemistry for Green Synthesis and Other Applications","authors":"B. Török, T. Mooney, Maysa Ilamanova","doi":"10.2174/2213335610666221208163107","DOIUrl":"https://doi.org/10.2174/2213335610666221208163107","url":null,"abstract":"\u0000\u0000Using combined microwave-assisted flow chemistry approaches is one of the most active areas of microwave chemistry and green synthesis. Microwave-assisted organic synthesis (MAOS) has contributed significantly to developing green synthetic methods, while flow chemistry applications are quite popular in industrial chemistry. The combination of the two has far-reaching advantages. In early studies, the flow chemistry concept was applied in domestic microwave ovens already indicating strong potential for future applications. The relatively small diameter of the flow reactors can address the limited penetration depth of microwaves, which is a major impediment in large-scale batch reactors. With the commercial availability of dedicated microwave synthesizers with tunable frequencies and better temperature control, the possibilities to apply flow synthesis grew even broader. The developments focus on several issues; the two major ones are the design and application of reactors and catalysts. Common reactor types include microwave-absorbing, such as silicon carbide, and microwave-transparent materials, such as borosilicate glass, quartz, or Teflon, with the catalyst or solvent adjusted accordingly. Several heterogeneous catalysts are considered strong microwave absorbers that can heat the reaction from inside the reactor. Such materials include clays, zeolites, or supported metal catalysts. Here, the major advances in design and applications and the benefits gained will be illustrated by synthesizing fine chemicals, from organic compounds to nanoparticles and new materials.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41789388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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