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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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}
Pub Date : 2022-08-20DOI: 10.2174/2213335609666220820153559
D. Karati, Dileep Kumar, K. Mahadik
The research aims to develop a sustainable microwave-assisted scheme for synthesizing 5-(benzylidene amino)-1-phenyl-1H-pyrazole-4-carbonitrile congeners. 5-(benzylideneamino)-1-phenyl-1H-pyrazole-4-carbonitrile scaffolds are novel molecules having various pharmacological activities such as neurodegenerative, anti-microbial, anti-cancer. Schiff base congeners are considered as efficient pharmacophores for research. These activities are due to the presence of azomethine (CH=N) group in the Schiff base compounds. To synthesise different novel Schiff base compounds of pyrazole nuclei by green chemistry with a decent yield. The 5-(benzylideneamino)-1-phenyl-1H-pyrazole-4-carbonitrile scaffolds were prepared by two step reactions. Both steps were microwave assisted. The first step was to synthesize 5-amino-1-phenyl-1H-pyrazole-4-carbonitrile as intermediate compound. This compound was synthesized by using phenyl hydrazine and 2-(ethoxymethylene)malononitrile. The temperature, pressure, and time required for this reaction were 1020C, 300W, and 45 minutes respectively. In the second step, the final Schiff base congeners were attained by reacting this compound with several aromatic aldehydes. The yield, reaction condition, and time consumption were all acceptable for the green synthetic methods rather than the conventional schemes. The microwave-assisted method was more efficient. The reactions were less time-consuming, and the overall yield of the all-synthesized compounds was 75-82%. Different spectroscopic methods characterized the synthesized congeners. The IR peak is considered the main functional group [azomethine] at 1611 cm-1 wavelength. This microwave-assisted synthetic scheme thus appears more environmentally due to a significant reduction in organic solvents, resulting in fewer hazardous residues. Using this scheme, we prepared different Schiff base congeners with satisfactory chemical yields
{"title":"Microwave Assisted Synthesis of a Novel Schiff Base Scaffolds of Pyrazole Nuclei: Green Synthetic Method","authors":"D. Karati, Dileep Kumar, K. Mahadik","doi":"10.2174/2213335609666220820153559","DOIUrl":"https://doi.org/10.2174/2213335609666220820153559","url":null,"abstract":"\u0000\u0000The research aims to develop a sustainable microwave-assisted scheme for synthesizing 5-(benzylidene amino)-1-phenyl-1H-pyrazole-4-carbonitrile congeners.\u0000\u0000\u0000\u00005-(benzylideneamino)-1-phenyl-1H-pyrazole-4-carbonitrile scaffolds are novel molecules having various pharmacological activities such as neurodegenerative, anti-microbial, anti-cancer. Schiff base congeners are considered as efficient pharmacophores for research. These activities are due to the presence of azomethine (CH=N) group in the Schiff base compounds.\u0000\u0000\u0000\u0000To synthesise different novel Schiff base compounds of pyrazole nuclei by green chemistry with a decent yield.\u0000\u0000\u0000\u0000The 5-(benzylideneamino)-1-phenyl-1H-pyrazole-4-carbonitrile scaffolds were prepared by two step reactions. Both steps were microwave assisted. The first step was to synthesize 5-amino-1-phenyl-1H-pyrazole-4-carbonitrile as intermediate compound. This compound was synthesized by using phenyl hydrazine and 2-(ethoxymethylene)malononitrile. The temperature, pressure, and time required for this reaction were 1020C, 300W, and 45 minutes respectively.\u0000In the second step, the final Schiff base congeners were attained by reacting this compound with several aromatic aldehydes. The yield, reaction condition, and time consumption were all acceptable for the green synthetic methods rather than the conventional schemes.\u0000\u0000\u0000\u0000The microwave-assisted method was more efficient. The reactions were less time-consuming, and the overall yield of the all-synthesized compounds was 75-82%. Different spectroscopic methods characterized the synthesized congeners. The IR peak is considered the main functional group [azomethine] at 1611 cm-1 wavelength.\u0000\u0000\u0000\u0000This microwave-assisted synthetic scheme thus appears more environmentally due to a significant reduction in organic solvents, resulting in fewer hazardous residues. Using this scheme, we prepared different Schiff base congeners with satisfactory chemical yields\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44405609","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 : 2022-05-18DOI: 10.2174/2213335609666220518100728
Krishnappa B Badiger, S. Khatavi, Kantharaju Kamanna
A variety of methods have been reported for the synthesis of pyrano[2,3-d]pyrimidines in the literature with some limitations, and generally used expensive catalysts, harmful solvent and prolonged reaction time. This paper describes an efficient and rapid multi-component synthesis of pyrano[2,3-d]pyrimidine through condensation of aromatic aldehyde, malononitrile and barbituric acid catalysed by agro-waste solvent catalyst under microwave irradiation. The present method provides several added advantages such as being environmentally friendly, simple work-up, inexpensive, and shorter reaction time affording excellent yields. The synthesized compounds were confirmed by various spectroscopic analysis such as FT-IR, 1H- & 13C-NMR and mass spectrometry. Develop an eco-friendly method for the synthesis of pyrano[2,3-d]pyrimidine derivatives. The pyrano[2,3-d]pyrimidine derivatives are prepared using an agro-waste-based catalyst, which avoids the use of the external base, additives and solvent in multi-component reactions. Further, the rate of the reaction is accelerated by custom-made microwave irradiation. The use of microwave irradiation showed many advantages over conventional methods such as reaction required less time, more yield and fewer by-products. Further, the custom-made microwave oven has the advantage of no spillage of any organic reagent or solvent to the microwave oven walls, because the reaction vessel is connected to a reflux condenser and direct exposure is avoided. We have selected Water Extract of Lemon Fruit Shell ash extract solvent as a greener homogenous organocatalysts, and reaction is accelerated by microwave irradiation for the inexpensive synthesis of pyrano[2,3-d]pyrimidine derivatives. In conclusion, we have developed a simple, efficient, agro-waste-based catalytic approach for the synthesis pyrano[2,3-d]pyrimidine derivatives employing WELFSA as an efficient agro-waste-based catalyst under microwave conditions. The method is found to added advantages of less hazardous, eco-friendly, metal-free, chemical-free, short reaction time, simple workup and isolated product in good to excellent yields.
{"title":"Microwave-Accelerated facile synthesis of pyrano[2,3-d]pyrimidine derivatives via one-pot strategy executed by agro-waste extract as a greener solvent media","authors":"Krishnappa B Badiger, S. Khatavi, Kantharaju Kamanna","doi":"10.2174/2213335609666220518100728","DOIUrl":"https://doi.org/10.2174/2213335609666220518100728","url":null,"abstract":"\u0000\u0000A variety of methods have been reported for the synthesis of pyrano[2,3-d]pyrimidines in the literature with some limitations, and generally used expensive catalysts, harmful solvent and prolonged reaction time. This paper describes an efficient and rapid multi-component synthesis of pyrano[2,3-d]pyrimidine through condensation of aromatic aldehyde, malononitrile and barbituric acid catalysed by agro-waste solvent catalyst under microwave irradiation. The present method provides several added advantages such as being environmentally friendly, simple work-up, inexpensive, and shorter reaction time affording excellent yields. The synthesized compounds were confirmed by various spectroscopic analysis such as FT-IR, 1H- & 13C-NMR and mass spectrometry.\u0000\u0000\u0000\u0000Develop an eco-friendly method for the synthesis of pyrano[2,3-d]pyrimidine derivatives.\u0000\u0000\u0000\u0000The pyrano[2,3-d]pyrimidine derivatives are prepared using an agro-waste-based catalyst, which avoids the use of the external base, additives and solvent in multi-component reactions. Further, the rate of the reaction is accelerated by custom-made microwave irradiation. The use of microwave irradiation showed many advantages over conventional methods such as reaction required less time, more yield and fewer by-products. Further, the custom-made microwave oven has the advantage of no spillage of any organic reagent or solvent to the microwave oven walls, because the reaction vessel is connected to a reflux condenser and direct exposure is avoided.\u0000\u0000\u0000\u0000We have selected Water Extract of Lemon Fruit Shell ash extract solvent as a greener homogenous organocatalysts, and reaction is accelerated by microwave irradiation for the inexpensive synthesis of pyrano[2,3-d]pyrimidine derivatives.\u0000\u0000\u0000\u0000In conclusion, we have developed a simple, efficient, agro-waste-based catalytic approach for the synthesis pyrano[2,3-d]pyrimidine derivatives employing WELFSA as an efficient agro-waste-based catalyst under microwave conditions. The method is found to added advantages of less hazardous, eco-friendly, metal-free, chemical-free, short reaction time, simple workup and isolated product in good to excellent yields.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42882998","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 : 2022-05-16DOI: 10.2174/2213335609666220516112247
S. Avula, N. Rehman, R. Csuk, B. Das, A. Al‐Harrasi
A variety of natural products reveal the presence of the 1H-1,2,3-triazole moiety in their chemical structures. In general, these molecules also play a significant role in the agrochemical, medicinal and pharmaceutical industries. Microwave-asisted reactions have attracted great interest for researchers to synthesize 1H-1,2,3-triazole compounds in shorter times with increased yields. The objective of this study is to optimize the purity and yield of the product, shorter the reaction time, and make the reaction more eco-friendly with the help of microwave-assisted organic synthesis. The present work elucidates a very simple but efficient and rapid, highly productive synthesis of various substituted 1H-1,2,3-triazole series, using the Suzuki-Miyaura cross-coupling reaction, employing microwave irradiation in water, with tetrabutylammonium bromide (TBAB). Utilizing (S)- (-) ethyl lactate as the starting material, the synthesis of the substituted 1H-1,2,3-triazole aryl bromide (1) was achieved. This compound (1) was subjected to the Suzuki-Miyaura cross-coupling reaction under microwave irradiation, using a variety of aryl boronic acids in an aqueous medium, to attain high yields of the target products, namely 3a-w. Overall, this is an environmentally benign, very efficient technique under microwave-irradiations as a green and eco-friendly source. Only those methodologies that involve microwave-assisted reactions during synthesis in a related manner have been reviewed. Microwave-assisted Suzuki-Miyaura cross-coupling reactions in water of substituted 1H-1,2,3-triazole series can be employed to quickly explore and increase molecular diversity in synthetic chemistry. In this respect, microwave-mediated methods help researchers to make helpful studies.
{"title":"Microwave-Assisted: An Efficient Aqueous Suzuki-Miyaura Cross-Coupling Reaction of the Substituted 1H-1,2,3-Triazoles","authors":"S. Avula, N. Rehman, R. Csuk, B. Das, A. Al‐Harrasi","doi":"10.2174/2213335609666220516112247","DOIUrl":"https://doi.org/10.2174/2213335609666220516112247","url":null,"abstract":"\u0000\u0000A variety of natural products reveal the presence of the 1H-1,2,3-triazole moiety in their chemical structures. In general, these molecules also play a significant role in the agrochemical, medicinal and pharmaceutical industries. Microwave-asisted reactions have attracted great interest for researchers to synthesize 1H-1,2,3-triazole compounds in shorter times with increased yields.\u0000\u0000\u0000\u0000The objective of this study is to optimize the purity and yield of the product, shorter the reaction time, and make the reaction more eco-friendly with the help of microwave-assisted organic synthesis.\u0000\u0000\u0000\u0000The present work elucidates a very simple but efficient and rapid, highly productive synthesis of various substituted 1H-1,2,3-triazole series, using the Suzuki-Miyaura cross-coupling reaction, employing microwave irradiation in water, with tetrabutylammonium bromide (TBAB). Utilizing (S)- (-) ethyl lactate as the starting material, the synthesis of the substituted 1H-1,2,3-triazole aryl bromide (1) was achieved.\u0000\u0000\u0000\u0000This compound (1) was subjected to the Suzuki-Miyaura cross-coupling reaction under microwave irradiation, using a variety of aryl boronic acids in an aqueous medium, to attain high yields of the target products, namely 3a-w. Overall, this is an environmentally benign, very efficient technique under microwave-irradiations as a green and eco-friendly source. Only those methodologies that involve microwave-assisted reactions during synthesis in a related manner have been reviewed.\u0000\u0000\u0000\u0000Microwave-assisted Suzuki-Miyaura cross-coupling reactions in water of substituted 1H-1,2,3-triazole series can be employed to quickly explore and increase molecular diversity in synthetic chemistry. In this respect, microwave-mediated methods help researchers to make helpful studies.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43323366","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 : 2022-04-14DOI: 10.2174/2213335609666220414141731
D. Karati, K. Mahadik, Dileep Kumar
The research work aims to develop sustainable microwave-assisted scheme for the synthesis of 4-(benzylidene amino)-6-phenylpyrimidine-5-carbonitrile congeners. 4-(benzylidene amino)-6-phenylpyrimidine-5-carbonitrile scaffolds are novel molecules having various pharmacological activities such as neurodegenerative, anti-microbial, anti-cancer. Schiff base congeners are considered as efficient pharmacophores for research. These activities are due to the presence of azomethine (CH=N) group in the Schiff base compounds. To synthesise different novel Schiff base scaffolds of pyrimidine nuclei by green chemistry with good yield. The 4-(benzylidene amino)-6-phenylpyrimidine-5-carbonitrile scaffolds were prepared by two step reactions. Both steps were microwave assisted. The first step was to synthesize 4-amino-6-phenylpyrimidine-5-carbonitrile as intermediate compound. This compound was synthesized by using benzaldehyde, malononitrile and formamidine hydrochloride. The reaction conditions are as following: temperature- 1010C, pressure- 300W, time- 50min. The final Schiff base congeners were obtained by reacting it with various aromatic aldehydes in the second step. The yield, reaction condition, and time consumption all were very acceptable for the green synthetic methods rather than the conventional schemes. Microwave assisted method was more efficient. The reactions were less time consuming and the overall yield of the all-synthesized compounds was in the range of 72-81%. The synthesized congeners were characterized by different spectroscopic methods. The main functional group [azomethine] was considered by the IR peak at 1611 cm-1 wavelength. This microwave assisted synthetic method thus emerges as more eco-friendly due to a much-reduced usage of organic solvents, leading to less harmful residues. Using this scheme, we synthesized different Schiff base congeners with satisfactory chemical yields.
{"title":"Microwave assisted synthetic scheme of a novel Schiff base congeners of pyrimidine nuclei by using water as solvent: green approach of synthesis","authors":"D. Karati, K. Mahadik, Dileep Kumar","doi":"10.2174/2213335609666220414141731","DOIUrl":"https://doi.org/10.2174/2213335609666220414141731","url":null,"abstract":"\u0000\u0000The research work aims to develop sustainable microwave-assisted scheme for the synthesis of 4-(benzylidene amino)-6-phenylpyrimidine-5-carbonitrile congeners.\u0000\u0000\u0000\u00004-(benzylidene amino)-6-phenylpyrimidine-5-carbonitrile scaffolds are novel molecules having various pharmacological activities such as neurodegenerative, anti-microbial, anti-cancer. Schiff base congeners are considered as efficient pharmacophores for research. These activities are due to the presence of azomethine (CH=N) group in the Schiff base compounds.\u0000\u0000\u0000\u0000To synthesise different novel Schiff base scaffolds of pyrimidine nuclei by green chemistry with good yield.\u0000\u0000\u0000\u0000The 4-(benzylidene amino)-6-phenylpyrimidine-5-carbonitrile scaffolds were prepared by two step reactions. Both steps were microwave assisted. The first step was to synthesize 4-amino-6-phenylpyrimidine-5-carbonitrile as intermediate compound. This compound was synthesized by using benzaldehyde, malononitrile and formamidine hydrochloride. The reaction conditions are as following: \u0000temperature- 1010C, pressure- 300W, time- 50min.\u0000The final Schiff base congeners were obtained by reacting it with various aromatic aldehydes in the second step. The yield, reaction condition, and time consumption all were very acceptable for the green synthetic methods rather than the conventional schemes.\u0000\u0000\u0000\u0000Microwave assisted method was more efficient. The reactions were less time consuming and the overall yield of the all-synthesized compounds was in the range of 72-81%. The synthesized congeners were characterized by different spectroscopic methods. The main functional group [azomethine] was considered by the IR peak at 1611 cm-1 wavelength.\u0000\u0000\u0000\u0000This microwave assisted synthetic method thus emerges as more eco-friendly due to a much-reduced usage of organic solvents, leading to less harmful residues. Using this scheme, we synthesized different Schiff base congeners with satisfactory chemical yields.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48323164","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 : 2022-03-24DOI: 10.2174/2213335609666220324144409
Subhraraj Panda
Ultrasonic research can be used to recognise molecular connections and structural behaviour of molecules. The combination of ultrasonic velocity, density, and viscosity data provides a plethora of information on ion interactions, dipoles, hydrogen bonding, multi-polar, and dispersive forces. To find out the molecular interaction of solute dextran of different concentration with distilled water as a solvent. The “ultrasonic speed (U), density (ρ), and viscosity (η)” at 323 K have been determined at four different frequencies, i.e.“1MHz,5MHz,9MHz and 12 MHz”. The derived acoustical parameters such as “acoustic impedance (Z), adiabatic compressibility (β), intermolecular free length (Lf), relaxation time (τ), Gibb’s free energy (ΔG)” have been determined from the experimental data. The significance gives subjective data with respect to nature and quality of the particles interactions between solute and solvent in the liquids solutions. To measure the density by specific gravity bottle, viscosity by Ostwald’s viscometer and ultrasonic velocity through ultrasonic interferometer of the solution and to calculate the thermo acoustical parameters using the measured parameters. Ultrasonic wave propagation affects the physical properties of the medium and hence furnishes information on the physics of liquid and solution. The measured parameters like ultrasonic velocity, density, and viscosity have been used to understand the solute-solute and solute-solvent interactions in the solution containing dextran with water. The effect of frequency on thermo acoustical parameters has been studied. From the above studies, the nature of forces between molecules such as hydrogen bonds, charge transfer complexes, breaking of hydrogen bonds and complexes has been interpreted.
{"title":"Analysis of Aqueous Dextran: An Ultrasonic Studies","authors":"Subhraraj Panda","doi":"10.2174/2213335609666220324144409","DOIUrl":"https://doi.org/10.2174/2213335609666220324144409","url":null,"abstract":"\u0000\u0000Ultrasonic research can be used to recognise molecular connections and structural behaviour of molecules. The combination of ultrasonic velocity, density, and viscosity data provides a plethora of information on ion interactions, dipoles, hydrogen bonding, multi-polar, and dispersive forces.\u0000\u0000\u0000\u0000To find out the molecular interaction of solute dextran of different concentration with distilled water as a solvent. The “ultrasonic speed (U), density (ρ), and viscosity (η)” at 323 K have been determined at four different frequencies, i.e.“1MHz,5MHz,9MHz and 12 MHz”. The derived acoustical parameters such as “acoustic impedance (Z), adiabatic compressibility (β), intermolecular free length (Lf), relaxation time (τ), Gibb’s free energy (ΔG)” have been determined from the experimental data. The significance gives subjective data with respect to nature and quality of the particles interactions between solute and solvent in the liquids solutions.\u0000\u0000\u0000\u0000To measure the density by specific gravity bottle, viscosity by Ostwald’s viscometer and ultrasonic velocity through ultrasonic interferometer of the solution and to calculate the thermo acoustical parameters using the measured parameters.\u0000\u0000\u0000\u0000Ultrasonic wave propagation affects the physical properties of the medium and hence furnishes information on the physics of liquid and solution. The measured parameters like ultrasonic velocity, density, and viscosity have been used to understand the solute-solute and solute-solvent interactions in the solution containing dextran with water.\u0000\u0000\u0000\u0000The effect of frequency on thermo acoustical parameters has been studied. From the above studies, the nature of forces between molecules such as hydrogen bonds, charge transfer complexes, breaking of hydrogen bonds and complexes has been interpreted.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45252746","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 : 2022-03-24DOI: 10.2174/2213335609666220324145341
F. Norouzi, N. Foroughifar, A. Khajeh-Amiri, H. Pasdar
Choline Chloride - Thiourea / Sulfuric Acid is a powerful and efficient green catalyst used for one-pot synthesis of quinazoline-4 (3H) -one derivatives via a reaction between various amines, acetic anhydride, and anthranilic acid under microwave irradiation and solvent-free conditions (4a-q). Microwave irradiation, which is a faster, more cost-effective, less energy-intensive, and more efficient method than conventional heating, has been used to synthesize some quinazolinone derivatives. For the past ten years, one of the major subjects in synthetic organic chemistry has been green synthesis, which has used efficient and environmentally friendly methods to synthesize biological compounds. The use of catalysts has significant advantages, including ease of preparation and separation, chemical and thermal stability, and environmental friendliness due to features such as reusability, low cost, and efficient, easy workup techniques. Therefore, the mechanism is performed by a non-toxic organic catalyst that uses the least energy and chemical reactants in accordance with the principles of green chemistry and least waste. One-pot and sequential addition methods have been used to synthesize quinazolinone derivatives. In the sequential addition method, the reaction was started by adding acetic anhydride and anthranilic acid to the reaction vessel under microwave irradiation and continued by adding choline chloride thiourea / sulfuric acid as efficient recyclable green catalysts and the desired amine. In vitro, the well diffusion method against different pathogenic strains was used to evaluate the antimicrobial activity of quinazoline-4 (3H) -one derivatives. Pathogenic strains used were Candida albicans ATCC 10231 (yeast), Aspergillus niger ATCC 16404 (fungus), Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 (bacteria) and ATCC 6538, and Staphylococcus aureus S. epidermidis ATCC 12228. Pyrimidine-containing compounds in which the 3-hydroxyl, 2,5-Dimethoxy, 4-bromo, 4 ‐ Methoxy, and 4 ‐ chloro groups are attached to the phenyl ring of pyrimidine exhibit antimicrobial properties. In a short reaction time, a variety of biologically active quinazolinone derivatives were synthesized with a high efficiency. According to the results, it was found that with aliphatic amines, the reaction time was shorter and the reaction efficiency was higher. Products synthesized from aromatic amines had more antibacterial properties. In this work, a variety of 2-methyl-quinazoline-4 (3H) -one derivatives (4a–q) were synthesized as potent antibacterial agents under microwave irradiation and solvent-free conditions in the presence of ChCl-thiourea / H2SO4 as an efficient, eco-friendly, and recyclable catalyst.
{"title":"A novel powerful Choline Chloride – Thiourea /Sulfuric Acid, efficient and recyclable catalyst via microwave‐assisted for the synthesis of Quinazolin- 4(3H)–one derivatives as Antibacterial Agents in green media","authors":"F. Norouzi, N. Foroughifar, A. Khajeh-Amiri, H. Pasdar","doi":"10.2174/2213335609666220324145341","DOIUrl":"https://doi.org/10.2174/2213335609666220324145341","url":null,"abstract":"\u0000\u0000Choline Chloride - Thiourea / Sulfuric Acid is a powerful and efficient green catalyst used for one-pot synthesis of quinazoline-4 (3H) -one derivatives via a reaction between various amines, acetic anhydride, and anthranilic acid under microwave irradiation and solvent-free conditions (4a-q). Microwave irradiation, which is a faster, more cost-effective, less energy-intensive, and more efficient method than conventional heating, has been used to synthesize some quinazolinone derivatives.\u0000\u0000\u0000\u0000For the past ten years, one of the major subjects in synthetic organic chemistry has been green synthesis, which has used efficient and environmentally friendly methods to synthesize biological compounds. The use of catalysts has significant advantages, including ease of preparation and separation, chemical and thermal stability, and environmental friendliness due to features such as reusability, low cost, and efficient, easy workup techniques. Therefore, the mechanism is performed by a non-toxic organic catalyst that uses the least energy and chemical reactants in accordance with the principles of green chemistry and least waste.\u0000\u0000\u0000\u0000One-pot and sequential addition methods have been used to synthesize quinazolinone derivatives. In the sequential addition method, the reaction was started by adding acetic anhydride and anthranilic acid to the reaction vessel under microwave irradiation and continued by adding choline chloride thiourea / sulfuric acid as efficient recyclable green catalysts and the desired amine. In vitro, the well diffusion method against different pathogenic strains was used to evaluate the antimicrobial activity of quinazoline-4 (3H) -one derivatives. Pathogenic strains used were Candida albicans ATCC 10231 (yeast), Aspergillus niger ATCC 16404 (fungus), Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 (bacteria) and ATCC 6538, and Staphylococcus aureus S. epidermidis ATCC 12228. Pyrimidine-containing compounds in which the 3-hydroxyl, 2,5-Dimethoxy, 4-bromo, 4 ‐ Methoxy, and 4 ‐ chloro groups are attached to the phenyl ring of pyrimidine exhibit antimicrobial properties.\u0000\u0000\u0000\u0000In a short reaction time, a variety of biologically active quinazolinone derivatives were synthesized with a high efficiency. According to the results, it was found that with aliphatic amines, the reaction time was shorter and the reaction efficiency was higher. Products synthesized from aromatic amines had more antibacterial properties.\u0000\u0000\u0000\u0000In this work, a variety of 2-methyl-quinazoline-4 (3H) -one derivatives (4a–q) were synthesized as potent antibacterial agents under microwave irradiation and solvent-free conditions in the presence of ChCl-thiourea / H2SO4 as an efficient, eco-friendly, and recyclable catalyst.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45890532","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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