Pub Date : 2020-12-07DOI: 10.2174/2213335607999201207151812
Jinjia Du, Yong Yang, M. Omran, Shenghui Guo
Microwave heating technology, as a new green metallurgical method, is the core technology used in metallurgical engineering. Based on a brief overview of the principle of microwave technology heating and its application in the metallurgical industry, this paper summarizes the latest research progress and development status of the current microwave heating technology in the hydrometallurgy leaching process and the trend of the application of microwave heating technology in metallurgy. A detailed classification and discussion on the leaching process of common metals were made. The purpose is to further improve the application level of the technology and provide technical support for the improvement of the market position of China’s metallurgical industry. Finally, the problems that need to be urgently solved in the hydrometallurgy of microwave-assisted leaching are further discussed and prospects and suggestions are also discussed.
{"title":"Research Status and Progress of Microwave Associated Leaching","authors":"Jinjia Du, Yong Yang, M. Omran, Shenghui Guo","doi":"10.2174/2213335607999201207151812","DOIUrl":"https://doi.org/10.2174/2213335607999201207151812","url":null,"abstract":"Microwave heating technology, as a new green metallurgical method, is the core technology\u0000used in metallurgical engineering. Based on a brief overview of the principle of microwave technology\u0000heating and its application in the metallurgical industry, this paper summarizes the latest research progress\u0000and development status of the current microwave heating technology in the hydrometallurgy\u0000leaching process and the trend of the application of microwave heating technology in metallurgy. A detailed\u0000classification and discussion on the leaching process of common metals were made. The purpose\u0000is to further improve the application level of the technology and provide technical support for the improvement\u0000of the market position of China’s metallurgical industry. Finally, the problems that need to\u0000be urgently solved in the hydrometallurgy of microwave-assisted leaching are further discussed and\u0000prospects and suggestions are also discussed.","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47387969","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 : 2020-11-30DOI: 10.2174/2213335607999200520124245
Samane Eftekhari, N. Foroughifar, S. Hallajian, A. Khajeh-Amiri
Schiff bases are excellent compounds. They were synthesized by condensation of active carbonyl and amines. They were widely used as a substrate in the preparation of industrial compounds as well as pharmaceutical purposes. They exhibit a wide range of biological activities. In this study, based on the importance of Schiff bases, a sustainable synthetic method was developed employing reflux and microwave irradiation. Develop a new synthetic method for imidazole Schiff base derivatives synthesis employing reflux, microwave irradiation, and ethanol as a green solvent. Synthesis of imidazole Schiff base derivatives was carried out under reflux and microwave irradiation conditions. Antibacterial activity of imidazole derivatives and standard drugs was examined against two Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and two Gramnegative bacteria (Proteus mirabilis, Escherichia coli). Schiff bases were synthesized in the presence of microwave irradiation and ethanol in high yields 90-98% for 2-4 min. The antibacterial effects of Schiff bases were evaluated against both strains of Gram-positive and Gram-negative. In this paper, a novel series of imidazole Schiff base derivatives were synthesized using reflux, microwave irradiation, and ethanol. Antibacterial effects were investigated. The excellent advantages of microwave irradiation in the synthesis of imidazole derivatives include reduction of reaction time from an hour to a minute, high product yield. In this study, the measurement of antibacterial activity was also important. Imidazole derivatives with Cl, OH, and CH3 groups showed antibacterial effects.
{"title":"Green Synthesis of Some Novel Imidazole Schiff base Derivatives Under Microwave Irradiation / Reflux Conditions and Evaluations of the Antibacterial Activity","authors":"Samane Eftekhari, N. Foroughifar, S. Hallajian, A. Khajeh-Amiri","doi":"10.2174/2213335607999200520124245","DOIUrl":"https://doi.org/10.2174/2213335607999200520124245","url":null,"abstract":"\u0000\u0000Schiff bases are excellent compounds. They were synthesized by condensation\u0000of active carbonyl and amines. They were widely used as a substrate in the preparation of industrial\u0000compounds as well as pharmaceutical purposes. They exhibit a wide range of biological activities.\u0000In this study, based on the importance of Schiff bases, a sustainable synthetic method was developed\u0000employing reflux and microwave irradiation.\u0000\u0000\u0000\u0000 Develop a new synthetic method for imidazole Schiff base derivatives synthesis employing reflux, microwave\u0000irradiation, and ethanol as a green solvent.\u0000\u0000\u0000\u0000Synthesis of imidazole Schiff base derivatives was carried out under reflux and microwave\u0000irradiation conditions. Antibacterial activity of imidazole derivatives and standard drugs was examined\u0000against two Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and two Gramnegative\u0000bacteria (Proteus mirabilis, Escherichia coli).\u0000\u0000\u0000\u0000Schiff bases were synthesized in the presence of microwave irradiation and ethanol in high\u0000yields 90-98% for 2-4 min. The antibacterial effects of Schiff bases were evaluated against both\u0000strains of Gram-positive and Gram-negative.\u0000\u0000\u0000\u0000In this paper, a novel series of imidazole Schiff base derivatives were synthesized using\u0000reflux, microwave irradiation, and ethanol. Antibacterial effects were investigated. The excellent advantages\u0000of microwave irradiation in the synthesis of imidazole derivatives include reduction of reaction\u0000time from an hour to a minute, high product yield. In this study, the measurement of antibacterial\u0000activity was also important. Imidazole derivatives with Cl, OH, and CH3 groups showed antibacterial\u0000effects.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45533123","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 : 2020-10-08DOI: 10.2174/2213335607999201008144429
H. Saeed, Devendra S. Wagare, Mujahed Shaikh, A. Durrani
A simple and highly efficient microwave-promoted procedure for the synthesis of imidazo[1,2-a]pyridine derivatives from the reaction of aromatic ketones, N-bromosuccinimide, and 2-aminopyridines in lemon juice was designed. The main advantages of this protocol, such as clean reaction profile, mild reaction condition, high yield, and minimum reaction time, were compared to other previously developed methods. A mixture of aromatic ketones (1a-m) (0.005 m), N-bromosuccinimide (NBS) (0.005 m), and lemon juice (10 ml) was irradiated by microwave at 400-watt power at 85°C, and the formation of α- bromoketones was monitored by Thin Layer Chromatography (TLC). After completion of α-bromination, 2-aminopyridines (0.005 m) was added to the reaction mixture and it was further irradiated at the same reaction condition. After completion of the reaction, the reaction mass was poured in ice-cold water, the solid product obtained was filtered, washed with cold water, and recrystallized from aqueous ethanol. In the present investigation, we have developed an environmentally benign, easy, and highly efficient one-pot procedure for the synthesis of 2-phenylimidazo [1, 2-a] pyridines from the reaction of aromatic ketones, N-bromosuccinimide, and 2-aminopyridines in lemon juice as a natural acid catalyst and solvent under microwave irradiation. This new protocol offers very attractive features such as minimum reaction time, clean reaction profile, mild reaction condition, and green aspects such as avoid poisonous catalyst, hazardous solvents, ease of the work-up procedure, and higher yield. In the present investigation, we have developed an environmentally benign, easy, and highly efficient one-pot procedure for the synthesis of 2-phenylimidazo [1, 2-a] pyridines from the reaction of aromatic ketones, N-bromosuccinimide, and 2-aminopyridines in lemon juice as a natural acid catalyst and solvent under microwave irradiation. This new protocol offers very attractive features such as minimum reaction time, clean reaction profile, mild reaction condition, and green aspects such as no need for a poisonous catalyst and hazardous solvents, ease of work-up procedure, and higher yield.
{"title":"Microwave-promoted One-pot Synthesis of Imidazo[1,2-a]pyridines in Lemon Juice","authors":"H. Saeed, Devendra S. Wagare, Mujahed Shaikh, A. Durrani","doi":"10.2174/2213335607999201008144429","DOIUrl":"https://doi.org/10.2174/2213335607999201008144429","url":null,"abstract":"\u0000\u0000A simple and highly efficient microwave-promoted procedure for the synthesis\u0000of imidazo[1,2-a]pyridine derivatives from the reaction of aromatic ketones, N-bromosuccinimide,\u0000and 2-aminopyridines in lemon juice was designed. The main advantages of this protocol,\u0000such as clean reaction profile, mild reaction condition, high yield, and minimum reaction time,\u0000were compared to other previously developed methods.\u0000\u0000\u0000\u0000A mixture of aromatic ketones (1a-m) (0.005 m), N-bromosuccinimide (NBS) (0.005 m),\u0000and lemon juice (10 ml) was irradiated by microwave at 400-watt power at 85°C, and the formation\u0000of α- bromoketones was monitored by Thin Layer Chromatography (TLC). After completion\u0000of α-bromination, 2-aminopyridines (0.005 m) was added to the reaction mixture and it was further\u0000irradiated at the same reaction condition. After completion of the reaction, the reaction mass was\u0000poured in ice-cold water, the solid product obtained was filtered, washed with cold water, and recrystallized\u0000from aqueous ethanol.\u0000\u0000\u0000\u0000In the present investigation, we have developed an environmentally benign, easy, and highly\u0000efficient one-pot procedure for the synthesis of 2-phenylimidazo [1, 2-a] pyridines from the reaction\u0000of aromatic ketones, N-bromosuccinimide, and 2-aminopyridines in lemon juice as a natural\u0000acid catalyst and solvent under microwave irradiation. This new protocol offers very attractive features\u0000such as minimum reaction time, clean reaction profile, mild reaction condition, and green aspects\u0000such as avoid poisonous catalyst, hazardous solvents, ease of the work-up procedure, and\u0000higher yield.\u0000\u0000\u0000\u0000In the present investigation, we have developed an environmentally benign, easy, and\u0000highly efficient one-pot procedure for the synthesis of 2-phenylimidazo [1, 2-a] pyridines from the\u0000reaction of aromatic ketones, N-bromosuccinimide, and 2-aminopyridines in lemon juice as a natural\u0000acid catalyst and solvent under microwave irradiation. This new protocol offers very attractive\u0000features such as minimum reaction time, clean reaction profile, mild reaction condition, and green\u0000aspects such as no need for a poisonous catalyst and hazardous solvents, ease of work-up procedure,\u0000and higher yield.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42019865","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 : 2020-08-31DOI: 10.2174/2213335607999200918155613
N. Patel, Hetal I. Soni, R. Parmar
To synthesise biologically active thiazolidin-4-one by microwave irradiation method and evaluate against different species of bacteria, fungi and Plasmodium falciparum. Microwave irradiation method is serviceable for rapid and sustainable synthesis. In this present study, Thiazolidin-4-one bearing pyrimidine derivatives have been synthesized by microwave irradiation method. Thiazolidin-4-one is a valuable motif because of its broad-spectrum biological evaluation. It is famous for many types of biological profiles, mainly antimicrobial, anti-tuberculosis, anti- convulsant, antihypertensive, hypoglycemic agent and antimalarial. This biological response leads our attention towards the change of Thiazolidin-4-one skeleton to enhance potential. Present study aims to carry out a rapid synthesis of Thiazolidin-4-one derivative of pyrimidine by microwave- assisted heating. 4-(4-substituted phenyl)-6-(substituted aryl) pyrimidin-2-amine was the key intermediate required for the synthesis of 3-(4-(Substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl)-2-(4-hydroxy phenyl) thiozolidin-4-one (5A-J), which was prepared by using microwave irradiation. The structures of all newly synthesized motifs were characterized by spectral analysis (IR, 1H NMR, 13C NMR spectroscopy) and screened for antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pyogenes; antifungal activity against Candida albicans, Aspergillus niger, Aspergillus Clavatus; anti-tuberculosis activity against M. tuberculosis H37RV and antimalarial activity against Plasmodium falciparum. Higher yield with less time-consuming method is the main advantage of Thiazolidin- 4-one bearing pyrimidine motifs synthesis. The excellent biological response of compounds 5B, 5C, 5D, 5G, 5H, 5I, and 5J was observed. As compared to conventional method, less time is required for the preparation of Thiazolidin- 4-one analogues by using advantageous microwave irradiation method. Thiazolidin-4-one derivatives showed improved biological activity.
{"title":"Significance of Microwave Irradiation in Synthesis of Thiazolidin-4-one Bearing Pyrimidine Analogues: Their in vitro Antimicrobial, Antituberculosis and Antimalarial Studies","authors":"N. Patel, Hetal I. Soni, R. Parmar","doi":"10.2174/2213335607999200918155613","DOIUrl":"https://doi.org/10.2174/2213335607999200918155613","url":null,"abstract":"\u0000\u0000To synthesise biologically active thiazolidin-4-one by microwave irradiation\u0000method and evaluate against different species of bacteria, fungi and Plasmodium falciparum.\u0000\u0000\u0000\u0000Microwave irradiation method is serviceable for rapid and sustainable synthesis. In\u0000this present study, Thiazolidin-4-one bearing pyrimidine derivatives have been synthesized by microwave\u0000irradiation method.\u0000\u0000\u0000\u0000Thiazolidin-4-one is a valuable motif because of its broad-spectrum biological evaluation.\u0000It is famous for many types of biological profiles, mainly antimicrobial, anti-tuberculosis, anti-\u0000convulsant, antihypertensive, hypoglycemic agent and antimalarial. This biological response\u0000leads our attention towards the change of Thiazolidin-4-one skeleton to enhance potential. Present\u0000study aims to carry out a rapid synthesis of Thiazolidin-4-one derivative of pyrimidine by microwave-\u0000assisted heating.\u0000\u0000\u0000\u00004-(4-substituted phenyl)-6-(substituted aryl) pyrimidin-2-amine was the key intermediate\u0000required for the synthesis of 3-(4-(Substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl)-2-(4-hydroxy\u0000phenyl) thiozolidin-4-one (5A-J), which was prepared by using microwave irradiation. The\u0000structures of all newly synthesized motifs were characterized by spectral analysis (IR, 1H NMR, 13C\u0000NMR spectroscopy) and screened for antibacterial activity against Escherichia coli, Pseudomonas\u0000aeruginosa, Staphylococcus aureus and Streptococcus pyogenes; antifungal activity against Candida\u0000albicans, Aspergillus niger, Aspergillus Clavatus; anti-tuberculosis activity against M. tuberculosis\u0000H37RV and antimalarial activity against Plasmodium falciparum.\u0000\u0000\u0000\u0000Higher yield with less time-consuming method is the main advantage of Thiazolidin-\u00004-one bearing pyrimidine motifs synthesis. The excellent biological response of compounds 5B,\u00005C, 5D, 5G, 5H, 5I, and 5J was observed.\u0000\u0000\u0000\u0000As compared to conventional method, less time is required for the preparation of Thiazolidin-\u00004-one analogues by using advantageous microwave irradiation method. Thiazolidin-4-one\u0000derivatives showed improved biological activity.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42101036","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 : 2020-08-31DOI: 10.2174/2213335607999201207151322
Shunda Lin, M. Omran, Shenghui Guo
Microwave heating technology is considered one of the most likely to replace traditional heating methods due to its efficient, quick, and green heating transmission that meets the requirements of sustainable development. Microwave heating can strengthen chemical reactions and change the morphology of minerals, and it can save energy and achieve rapid and efficient heating, clean production, and emission reduction. Therefore, this paper summarizes the research status of microwave heating in the recovery of valuable metals (Cu, Au, V),) from metallurgical waste ore and rare earth elements from rare earth minerals in recent years, expounds the principle of microwave heating, and summarizes the previous experimental phenomena. Finally, the development potential, opportunities, and difficulties of microwave technology in future industrial applications are discussed.
{"title":"Recovery of Metals and Rare Earth Elements by Microwave heating Technology - A Review","authors":"Shunda Lin, M. Omran, Shenghui Guo","doi":"10.2174/2213335607999201207151322","DOIUrl":"https://doi.org/10.2174/2213335607999201207151322","url":null,"abstract":"\u0000\u0000Microwave heating technology is considered one of the most likely to replace traditional\u0000heating methods due to its efficient, quick, and green heating transmission that meets the requirements\u0000of sustainable development. Microwave heating can strengthen chemical reactions and change\u0000the morphology of minerals, and it can save energy and achieve rapid and efficient heating, clean\u0000production, and emission reduction. Therefore, this paper summarizes the research status of microwave\u0000heating in the recovery of valuable metals (Cu, Au, V),) from metallurgical waste ore and rare\u0000earth elements from rare earth minerals in recent years, expounds the principle of microwave heating,\u0000and summarizes the previous experimental phenomena. Finally, the development potential, opportunities,\u0000and difficulties of microwave technology in future industrial applications are discussed.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46080924","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 : 2020-08-06DOI: 10.2174/221333560702200714141435
B. Banerjee
{"title":"Microwave-assisted Carbon-Carbon and Carbon-Heteroatom Bond Forming Reactions - Part 1B","authors":"B. Banerjee","doi":"10.2174/221333560702200714141435","DOIUrl":"https://doi.org/10.2174/221333560702200714141435","url":null,"abstract":"","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47837025","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 : 2020-07-01DOI: 10.2174/2213335607666200701214200
Mengmeng Li, Shuang Huang, Han Zhang, Lei Wang, Shengliang Zhong
Researchers have pursued the new synthesis method. As a newly developed method, microwave (MW), ultrasound (US) and ultraviolet light (UV) assisted synthesis has drawn increasing interests. Under the synergistic effect, many materials with new structure, morphology and properties may be found. As an important rare-earth phosphate, DyPO4 was selected and the effect of MW, US and UV on the preparation was investigated. The DyPO4·1.5H2O nanostructures were prepared by MW, US, UV and their combination. Hexagonal DyPO4·1.5H2O microcrystals obtained under MW irradiation were broomstick bundles. Needle-shaped products were formed in the presence of MW and US. Interestingly, the broom-sheaf-like structures can self-assemble into flower-shaped structures upon the irradiation of MW and UV. Whereas, MW/UV/US synergetic heating results in mixed morphologies of flower-like and needle-shaped structures. The growth of DyPO4 nanostructures can be tuned by selecting the combination of heating method of MW, US and UV.
{"title":"DyPO4·1.5H2O Microcrystals: Microwave/Ultrasound/ Ultraviolet Light- Assisted Synthesis, Characterization and Formation Mechanism","authors":"Mengmeng Li, Shuang Huang, Han Zhang, Lei Wang, Shengliang Zhong","doi":"10.2174/2213335607666200701214200","DOIUrl":"https://doi.org/10.2174/2213335607666200701214200","url":null,"abstract":"\u0000\u0000Researchers have pursued the new synthesis method. As a newly developed\u0000method, microwave (MW), ultrasound (US) and ultraviolet light (UV) assisted synthesis has drawn\u0000increasing interests. Under the synergistic effect, many materials with new structure, morphology and\u0000properties may be found. As an important rare-earth phosphate, DyPO4 was selected and the effect of\u0000MW, US and UV on the preparation was investigated.\u0000\u0000\u0000\u0000The DyPO4·1.5H2O nanostructures were prepared by MW, US, UV and their combination.\u0000\u0000\u0000\u0000Hexagonal DyPO4·1.5H2O microcrystals obtained under MW irradiation were broomstick\u0000bundles. Needle-shaped products were formed in the presence of MW and US. Interestingly, the\u0000broom-sheaf-like structures can self-assemble into flower-shaped structures upon the irradiation of\u0000MW and UV. Whereas, MW/UV/US synergetic heating results in mixed morphologies of flower-like\u0000and needle-shaped structures.\u0000\u0000\u0000\u0000The growth of DyPO4 nanostructures can be tuned by selecting the combination of heating\u0000method of MW, US and UV.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43133579","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}