Pub Date : 2022-11-04DOI: 10.2174/2213337210666221104101425
K. Kantharaju, Vasant T Tonape, Aravind D Kamath
Several types of catalysts have been cited in the literature. However, the current work showed that a multi-component reaction involving aldehydes, malononitrile, and resorcinol or α/β-naphthol could produce 2-amino-4H-chromene in a more environmentally friendly manner. The reaction is optimized by both stirring and microwave methods, but the reaction carried out under microwave irradiation is found to be faster with easy separation of the product with high yield and purity. The catalyst is analyzed for the presence of elemental composition using Flame Photometry (FP) and SEM-EDX. The synthesis of 2-amino-4H-chromenes is catalyzed by the new, green catalyst HRSPLAE (Water Extract of Hibiscus Rosa Sinensis plant dry leaves ash) within 3-5 min. The final product is analyzed by FT-IR, 1H-, 13C-NMR, and mass spectrometry techniques and the product obtained is free from the use of chromatographic separation with isolation and yield of 80–95%. Selected 2-amino-4H-chromene derivatives (4b and 4c) were screened for their anti-cancer and antimicrobial activity in vitro. The agro-waste sourced from Hibiscus rosa-sinensis plant dry leaves ash is utilized for the preparation of HRSPLAE catalyst, which is employed for the synthesis of 2-amino-4H-chromene derivatives under microwave irradiation. 2-Amino-4H-chromene derivatives were obtained from aromatic aldehyde, malononitrile, and resorcinol or α/β naphthol catalyzed by HRSPLAE. They were comprehensively evaluated using flame emission spectrometry, SEM, and EDX. HRSPLAE outperforms expensive catalysts. An efficient simpler workup without column chromatography for increased yield through a new unique green method for the synthesis of 2-amino-4H-chromene derivatives has been developed.
{"title":"Eco-friendly Synthesis of 2-Amino-4H-Chromene Catalysed by HRSPLAE and Anti-Cancer Activity Studies","authors":"K. Kantharaju, Vasant T Tonape, Aravind D Kamath","doi":"10.2174/2213337210666221104101425","DOIUrl":"https://doi.org/10.2174/2213337210666221104101425","url":null,"abstract":"\u0000\u0000Several types of catalysts have been cited in the literature. However, the current work showed that a multi-component reaction involving aldehydes, malononitrile, and resorcinol or α/β-naphthol could produce 2-amino-4H-chromene in a more environmentally friendly manner. The reaction is optimized by both stirring and microwave methods, but the reaction carried out under microwave irradiation is found to be faster with easy separation of the product with high yield and purity. The catalyst is analyzed for the presence of elemental composition using Flame Photometry (FP) and SEM-EDX. The synthesis of 2-amino-4H-chromenes is catalyzed by the new, green catalyst HRSPLAE (Water Extract of Hibiscus Rosa Sinensis plant dry leaves ash) within 3-5 min. The final product is analyzed by FT-IR, 1H-, 13C-NMR, and mass spectrometry techniques and the product obtained is free from the use of chromatographic separation with isolation and yield of 80–95%. Selected 2-amino-4H-chromene derivatives (4b and 4c) were screened for their anti-cancer and antimicrobial activity in vitro.\u0000\u0000\u0000\u0000The agro-waste sourced from Hibiscus rosa-sinensis plant dry leaves ash is utilized for the preparation of HRSPLAE catalyst, which is employed for the synthesis of 2-amino-4H-chromene derivatives under microwave irradiation.\u0000\u0000\u0000\u00002-Amino-4H-chromene derivatives were obtained from aromatic aldehyde, malononitrile, and resorcinol or α/β naphthol catalyzed by HRSPLAE. They were comprehensively evaluated using flame emission spectrometry, SEM, and EDX.\u0000\u0000\u0000\u0000HRSPLAE outperforms expensive catalysts. An efficient simpler workup without column chromatography for increased yield through a new unique green method for the synthesis of 2-amino-4H-chromene derivatives has been developed.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41639663","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 : 2022-11-03DOI: 10.2174/2213337210666221103122755
V. Srivastava
The synthesis of Proline-2-triethyl-ethylamide hexafluorophosphate (ILPA-PF6) (with 96% yield) and further the application during the synthesis of (R)-9-Methyl-5(10)-octaline-1,6-dione (Wieland–Miescher ketone molecule) are defined in this manuscript. The suggested protocol signifies one of the most efficient methods for the synthesis of these flexible chiral building blocks in good yield. The evident solubility of ionic liquids allows straightforward isolation of the (R)-9-Methyl-5(10)-octaline-1,6-dione product from reaction mass. Additionally, six times catalyst recycling was considered the main conclusion of this proposed procedure. We report the synthesis of a triethyl salt anchored pyrrolidine amide organocatalyst. The route for the synthesis of Proline-2-triethyl-ethylamide hexafluorophosphate ionic liquid is described in Scheme 1. In the first part of the synthesis commercially available Boc-proline, was allowed to react with 2-bromo-ethylamine hydrobromide to obtain N-Boc-proline-2-bromo-ethylamide. Subsequent alkylation of triethylamine with N-Boc-proline-2-bromo-ethylamide gave N-Boc-proline-2-triethyl-ethylamide bromide in 92% yield. After the Boc deprotection step and subsequent anion exchange in water with KPF6, afforded the desired air-stable pale-yellow and transparent Proline-2-triethyl-ethylamide hexafluorophosphate ionic liquid (Proline-2-triethyl-ethylamide hexafluorophosphate, ILPA-PF6) with 97% yield. None
{"title":"Preparation of Ionic Liquid Supported Organocatalysts for the Synthesis of Stereoselective (R)-9-Methyl-5(10)-octaline-1,6-dione","authors":"V. Srivastava","doi":"10.2174/2213337210666221103122755","DOIUrl":"https://doi.org/10.2174/2213337210666221103122755","url":null,"abstract":"\u0000\u0000The synthesis of Proline-2-triethyl-ethylamide hexafluorophosphate (ILPA-PF6) (with 96% yield) and further the application during the synthesis of (R)-9-Methyl-5(10)-octaline-1,6-dione (Wieland–Miescher ketone molecule) are defined in this manuscript. The suggested protocol signifies one of the most efficient methods for the synthesis of these flexible chiral building blocks in good yield. The evident solubility of ionic liquids allows straightforward isolation of the (R)-9-Methyl-5(10)-octaline-1,6-dione product from reaction mass. Additionally, six times catalyst recycling was considered the main conclusion of this proposed procedure.\u0000\u0000\u0000\u0000We report the synthesis of a triethyl salt anchored pyrrolidine amide organocatalyst. The route for the synthesis of Proline-2-triethyl-ethylamide hexafluorophosphate ionic liquid is described in Scheme 1. In the first part of the synthesis commercially available Boc-proline, was allowed to react with 2-bromo-ethylamine hydrobromide to obtain N-Boc-proline-2-bromo-ethylamide. Subsequent alkylation of triethylamine with N-Boc-proline-2-bromo-ethylamide gave N-Boc-proline-2-triethyl-ethylamide bromide in 92% yield. After the Boc deprotection step and subsequent anion exchange in water with KPF6, afforded the desired air-stable pale-yellow and transparent Proline-2-triethyl-ethylamide hexafluorophosphate ionic liquid (Proline-2-triethyl-ethylamide hexafluorophosphate, ILPA-PF6) with 97% yield.\u0000\u0000\u0000\u0000None\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43961865","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 : 2022-08-02DOI: 10.2174/2213337209666220802105301
R. N. Yadav, A. Shaikh, Aparna Das, D. Ray, B. Banik
The aim of this study is to investigate the p-toluene sulphonic acid (p-Ts.OH) catalyzed reaction of racemic-azetidine-2,3-diones with enantiomerically pure cis and trans-4-hydroxy-L-proline in refluxing ethanol culminating in a synthesis of substituted novel 3-(pyrrol-1-yl)-azetidin-2-ones at the C-3 position. This work describes an alternative synthetic route enabling the tandem transformation of proline to pyrrole, followed by intramolecular chirality transfer to the -lactams ring. All four diastereomers of 3-(pyrrol-1-yl)-azetidin-2-ones could be achieved in good to excellent yield with high diastereoselectivity in a single-pot operation.
{"title":"Asymmetric Synthesis of 3-Pyrrole Substituted -Lactams Through p-Toluene sulphonic Acid-Catalyzed Reaction of azetidine-2,3-diones with Hydroxyprolines","authors":"R. N. Yadav, A. Shaikh, Aparna Das, D. Ray, B. Banik","doi":"10.2174/2213337209666220802105301","DOIUrl":"https://doi.org/10.2174/2213337209666220802105301","url":null,"abstract":"\u0000\u0000The aim of this study is to investigate the p-toluene sulphonic acid (p-Ts.OH) catalyzed reaction of racemic-azetidine-2,3-diones with enantiomerically pure cis and trans-4-hydroxy-L-proline in refluxing ethanol culminating in a synthesis of substituted novel 3-(pyrrol-1-yl)-azetidin-2-ones at the C-3 position. This work describes an alternative synthetic route enabling the tandem transformation of proline to pyrrole, followed by intramolecular chirality transfer to the -lactams ring. All four diastereomers of 3-(pyrrol-1-yl)-azetidin-2-ones could be achieved in good to excellent yield with high diastereoselectivity in a single-pot operation.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":"28 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41298646","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 : 2022-07-28DOI: 10.2174/2213337209666220728114131
R. Tafer, R. Boulcina, A. Debache
The synthesis of 2-azapyrrolizidine scaffolds has fascinated scientists due to their potential biological activities. An efficient and environmentally sustainable synthetic method has been presented to synthesize structurally various 2-azapyrrolizidines via three-component reaction. The condensation of aldehydes, hydantoin, and malononitrile in the presence of green and sustainable sulfamic acid as catalyst in mild conditions has been achieved. The present protocol leads in most cases to the desired products in high yields. The synthetic efficiency and operational simplicity make the present procedure cost effective, time efficient and eco-friendly for the synthesis of substituted 2-azapyrrolizidines.
{"title":"A novel idea of sulfamic acid as an efficient catalyst for the synthesis of 2-azapyrrolizidine derivatives","authors":"R. Tafer, R. Boulcina, A. Debache","doi":"10.2174/2213337209666220728114131","DOIUrl":"https://doi.org/10.2174/2213337209666220728114131","url":null,"abstract":"\u0000\u0000The synthesis of 2-azapyrrolizidine scaffolds has fascinated scientists due to their potential biological activities.\u0000\u0000\u0000\u0000An efficient and environmentally sustainable synthetic method has been presented to synthesize structurally various 2-azapyrrolizidines via three-component reaction.\u0000\u0000\u0000\u0000The condensation of aldehydes, hydantoin, and malononitrile in the presence of green and sustainable sulfamic acid as catalyst in mild conditions has been achieved.\u0000\u0000\u0000\u0000The present protocol leads in most cases to the desired products in high yields.\u0000\u0000\u0000\u0000The synthetic efficiency and operational simplicity make the present procedure cost effective, time efficient and eco-friendly for the synthesis of substituted 2-azapyrrolizidines.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46301002","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 : 2022-07-28DOI: 10.2174/2213337209666220728094248
José Ferraz-Caetano
This brief perspective outlines the pivotal role of Machine Learning methods in the green, digital transition of industrial chemistry. The focus on homogenous catalysis highlights the recent methodologies in the development of industrial processes, including the design of new catalysts and the enhancement of sustainable reaction conditions to lower production costs. We report several examples of Machine Learning assisted methodologies through recent Data Science trends on innovation of industrial homogeneous organocatalytic systems. We also stress the current benefits, drawbacks, and limitations towards the mass implementation of these Data Science methodologies.
{"title":"Current Outlooks on Machine Learning Methods for the Development of Industrial Homogeneous Catalytic Systems","authors":"José Ferraz-Caetano","doi":"10.2174/2213337209666220728094248","DOIUrl":"https://doi.org/10.2174/2213337209666220728094248","url":null,"abstract":"\u0000\u0000This brief perspective outlines the pivotal role of Machine Learning methods in the green, digital transition of industrial chemistry. The focus on homogenous catalysis highlights the recent methodologies in the development of industrial processes, including the design of new catalysts and the enhancement of sustainable reaction conditions to lower production costs. We report several examples of Machine Learning assisted methodologies through recent Data Science trends on innovation of industrial homogeneous organocatalytic systems. We also stress the current benefits, drawbacks, and limitations towards the mass implementation of these Data Science methodologies.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43875294","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 : 2022-05-25DOI: 10.2174/2213337209666220525161703
Raziyeh Keshavarz, Mahnaz Farahi
Carbon-based materials, due to their unique properties such as lightweight, many varieties of forms, doping capability with hetero atoms, low cost, and ease of processability, are suitable support, for heterogeneous catalysts. Among them, cellulose, as one of the most abundant and renewable organic polymers, preserves a key position in many organic raw materials. Pyranopyrimidine derivatives, due to their high biological activity are of interest to both medicinal chemists and biochemists. Moreover, they play the most fundamental structural role in many natural compounds and medicinally useful molecules. Owing to the great variety of biologically active pyridines, it is not surprising that the pyridine ring system has become a vital basic component in many pharmaceutical agents. In this study, cellulose as heterogeneous support was used to prepare an efficient solid catalyst. Cellulose, as the most abundant organic polymer, is a suitable material for this purpose. Then, by immobilizing polyoxomolybdate by a linker on the surface of this carbon-based material, we succeeded in producing Cell@(CH2)3N=Mo[Mo5O18] nanocatalyst. The structure and properties of this catalyst were confirmed by various analyzes including FT-IR, XRD, EDS-map, FE-SEM, and TGA, and its efficacy was evaluated by its use in the preparation of Pyrano[2,3-d]pyrimidine derivatives through a multicomponent reaction between aryl aldehydes, malononitrile, and barbituric acid. The results of this study showed that this new and non-toxic organo-inorganic hybrid nanocatalyst provides the desired products in a short time and with appropriate efficiency. The key features of the present protocol include reusability of the catalyst, ease of recovery, ambient reaction conditions, and simple work-up procedure that make it economic and sustainable.
{"title":"Cellulose Supported Propylamine/Molybdate Complex: A Novel and Recyclable Nanocatalyst for the Synthesis of Pyranopyrimidine Derivatives","authors":"Raziyeh Keshavarz, Mahnaz Farahi","doi":"10.2174/2213337209666220525161703","DOIUrl":"https://doi.org/10.2174/2213337209666220525161703","url":null,"abstract":"\u0000\u0000Carbon-based materials, due to their unique properties such as lightweight, many varieties of forms, doping capability with hetero atoms, low cost, and ease of processability, are suitable support, for heterogeneous catalysts. Among them, cellulose, as one of the most abundant and renewable organic polymers, preserves a key position in many organic raw materials.\u0000Pyranopyrimidine derivatives, due to their high biological activity are of interest to both medicinal chemists and biochemists. Moreover, they play the most fundamental structural role in many natural compounds and medicinally useful molecules. Owing to the great variety of biologically active pyridines, it is not surprising that the pyridine ring system has become a vital basic component in many pharmaceutical agents.\u0000\u0000\u0000\u0000In this study, cellulose as heterogeneous support was used to prepare an efficient solid catalyst. Cellulose, as the most abundant organic polymer, is a suitable material for this purpose. Then, by immobilizing polyoxomolybdate by a linker on the surface of this carbon-based material, we succeeded in producing Cell@(CH2)3N=Mo[Mo5O18] nanocatalyst. The structure and properties of this catalyst were confirmed by various analyzes including FT-IR, XRD, EDS-map, FE-SEM, and TGA, and its efficacy was evaluated by its use in the preparation of Pyrano[2,3-d]pyrimidine derivatives through a multicomponent reaction between aryl aldehydes, malononitrile, and barbituric acid.\u0000\u0000\u0000\u0000The results of this study showed that this new and non-toxic organo-inorganic hybrid nanocatalyst provides the desired products in a short time and with appropriate efficiency.\u0000\u0000\u0000\u0000The key features of the present protocol include reusability of the catalyst, ease of recovery, ambient reaction conditions, and simple work-up procedure that make it economic and sustainable.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46743425","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 : 2022-05-17DOI: 10.2174/1389200223666220517124125
Zohreh Mahmoudi, H. Kabirifard, M. Ghasemzadeh
In this study, a heterogeneous catalyst containing MIL-101(Cr) functionalized TEDA-BAIL was used to achieve an efficient four-component reaction between aromatic aldehydes, barbituric acid, dimedone, and aryl amines, resulting in the synthesis of a new class of pyrimido[4,5-b]quinolinetrione derivatives. Pyrimido[4,5-b]quinolinetriones were synthesized through a one-pot four-component reaction between aromatic aldehydes, barbituric acid, dimedone, and aryl amines, in the presence of triethylenediamine-based ionic liquid@MIL-101(Cr) composite as a catalyst under reflux conditions. The TEDA-BAIL@MIL-101(Cr), which is a recoverable catalyst, was fully characterized by Fourier transform infrared spectrophotometry (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) and Transmission electron microscopy (TEM). Four-component synthesis of pyrimido[4,5-b]quinolinetriones catalyzed by TEDA-BAIL@MIL-101(Cr) with aromatic aldehydes, barbituric acid, dimedone, and aryl amines under reflux conditions. The obtained experimental results revealed that the employed synthesis approach is a simple method which offers several advantages including sustainability, facile separation from the reaction medium, and reusability after six consecutive runs without loss of activity. The present method is an efficient method for the synthesis of pyrimido[4,5-b]quinolinetriones in the presence of TEDA-BAIL@MIL-101(Cr) under reflux conditions. This procedure provides multiple advantages such as ease of execution, high yields, clean reaction conditions, shorter reaction time, and catalyst sustainability.
{"title":"MIL-101(Cr)Functionalized TEDA-BAIL: An Efficient and Recyclable Catalyst for Synthesis of Pyrimido[4,5-b]quinolinetrione Derivatives","authors":"Zohreh Mahmoudi, H. Kabirifard, M. Ghasemzadeh","doi":"10.2174/1389200223666220517124125","DOIUrl":"https://doi.org/10.2174/1389200223666220517124125","url":null,"abstract":"\u0000\u0000In this study, a heterogeneous catalyst containing MIL-101(Cr) functionalized TEDA-BAIL was used to achieve an efficient four-component reaction between aromatic aldehydes, barbituric acid, dimedone, and aryl amines, resulting in the synthesis of a new class of pyrimido[4,5-b]quinolinetrione derivatives.\u0000\u0000\u0000\u0000Pyrimido[4,5-b]quinolinetriones were synthesized through a one-pot four-component reaction between aromatic aldehydes, barbituric acid, dimedone, and aryl amines, in the presence of triethylenediamine-based ionic liquid@MIL-101(Cr) composite as a catalyst under reflux conditions. The TEDA-BAIL@MIL-101(Cr), which is a recoverable catalyst, was fully characterized by Fourier transform infrared spectrophotometry (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) and Transmission electron microscopy (TEM).\u0000\u0000\u0000\u0000Four-component synthesis of pyrimido[4,5-b]quinolinetriones catalyzed by TEDA-BAIL@MIL-101(Cr) with aromatic aldehydes, barbituric acid, dimedone, and aryl amines under reflux conditions. The obtained experimental results revealed that the employed synthesis approach is a simple method which offers several advantages including sustainability, facile separation from the reaction medium, and reusability after six consecutive runs without loss of activity.\u0000\u0000\u0000\u0000The present method is an efficient method for the synthesis of pyrimido[4,5-b]quinolinetriones in the presence of TEDA-BAIL@MIL-101(Cr) under reflux conditions. This procedure provides multiple advantages such as ease of execution, high yields, clean reaction conditions, shorter reaction time, and catalyst sustainability.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42269355","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 : 2022-05-12DOI: 10.2174/2213337209666220512093626
Anjitha Satheesh, Gopika Gokuldas, K. Gayathri, E. Kandasamy
Quinazolinones are a class of heterocyclic compounds that have a wide variety of applications. They are also used in agrochemicals. There are several methodologies reported for the synthesis of 2,3-dihydroquinazolines using various catalysts. Here, by using 1-butyl-1,2,4-triazolium as cation and trifluoroacetate as anion, 2,3-dihydroquinazolin-4(1H)-one has been synthesized. For the synthesis of 2,3-dihydroquinazolin-4(1H)-one condensation of anthranilamide with the corresponding aldehyde in the presence of organocatalyst and solvent is done. Using benzaldehyde as the parent aldehyde, to validate the outcome, the benzaldehydes were selected as follows a) benzaldehyde, b) 4-methoxybenzaldehyde – electron releasing group and c) 4-nitrobenzaldehyde – electronwithdrawing group. Solvent study has been done with solvents varied from polar to apolar. Both polar protic and polar aprotic solvents are used for the reactions. The polar protic solvents used were water, methanol, ethanol, isopropanol, butanol, hexane-1-ol, and glycerol. The polar aprotic solvents used are ethyl acetate, DMF,acetonitrile, and DMSO. The moderately apolar solvents used are DCM, carbon tetrachloride, 1,4 dioxane, and chloroform. The synthesized triazolium salts are found soluble in polar aprotic, polar protic solvents and few moderately apolar solvents such as DCM, chloroform, acetonitrile, water, methanol and ethanol whereas insoluble with apolar solvents like toluene, benzene, and hexane.The yield of 2-phenyl-2,3-dihydroquinazolin-4(1H)-one was low for 1-butyl-1,2,4-triazolium trifluoroacetate based organocatalyst. But for substituted benzaldehyde, the yield was comparatively high. Comparatively, the yield for 2-(4-methoxyphenyl)-2,3-dihydroquinazolin-4(1H)-one, where the aromatic benzaldehyde had electron-donating group, is less than 2-(4-nitrophenyl)-2,3-dihydroquinazolin-4(1H)-one, where the aromatic benzaldehyde had an electron-withdrawing group. Substituted benzaldehyde gave better yields than benzaldehyde. And nitro group which is electrowithdrawing attached to benzaldehyde enhanced the electrophilic nature at carbonyl center showed higher yields than methoxy group which is electron donating attached to benzaldehyde as it deactivates the carbonyl carbon. The polar protic solvents like water, ethanol and methanol stabilizes the ionic intermediates and gave better yield. Even the moderately apolar solvents like DCM, chloroform resulted in good yields, green solvents like water, ethanol and methanol would be a better choice as solvents. The carbon chain on the solvent has got an effect on product yield. As the carbon chain increases in solvent, the yield decreases due to the separation difficulties. The polar aprotic solvents did gave better yields but not as good as polar protic solvents.
{"title":"Effect of Solvents in 1-Butyl-1,2,4-Triazolium Trifluoroacetate Triggered Synthesis of 2,3-Dihydroquinazolin..","authors":"Anjitha Satheesh, Gopika Gokuldas, K. Gayathri, E. Kandasamy","doi":"10.2174/2213337209666220512093626","DOIUrl":"https://doi.org/10.2174/2213337209666220512093626","url":null,"abstract":"\u0000\u0000Quinazolinones are a class of heterocyclic compounds that have a wide variety of applications. They are also used in agrochemicals. There are several methodologies reported for the synthesis of 2,3-dihydroquinazolines using various catalysts.\u0000\u0000\u0000\u0000Here, by using 1-butyl-1,2,4-triazolium as cation and trifluoroacetate as anion, 2,3-dihydroquinazolin-4(1H)-one has been synthesized. For the synthesis of 2,3-dihydroquinazolin-4(1H)-one condensation of anthranilamide with the corresponding aldehyde in the presence of organocatalyst and solvent is done. Using benzaldehyde as the parent aldehyde, to validate the outcome, the benzaldehydes were selected as follows a) benzaldehyde, b) 4-methoxybenzaldehyde – electron releasing group and c) 4-nitrobenzaldehyde – electronwithdrawing group. Solvent study has been done with solvents varied from polar to apolar. Both polar protic and polar aprotic solvents are used for the reactions. The polar protic solvents used were water, methanol, ethanol, isopropanol, butanol, hexane-1-ol, and glycerol. The polar aprotic solvents used are ethyl acetate, DMF,acetonitrile, and DMSO. The moderately apolar solvents used are DCM, carbon tetrachloride, 1,4 dioxane, and chloroform.\u0000\u0000\u0000\u0000The synthesized triazolium salts are found soluble in polar aprotic, polar protic solvents and few moderately apolar solvents such as DCM, chloroform, acetonitrile, water, methanol and ethanol whereas insoluble with apolar solvents like toluene, benzene, and hexane.The yield of 2-phenyl-2,3-dihydroquinazolin-4(1H)-one was low for 1-butyl-1,2,4-triazolium trifluoroacetate based organocatalyst. But for substituted benzaldehyde, the yield was comparatively high. Comparatively, the yield for 2-(4-methoxyphenyl)-2,3-dihydroquinazolin-4(1H)-one, where the aromatic benzaldehyde had electron-donating group, is less than 2-(4-nitrophenyl)-2,3-dihydroquinazolin-4(1H)-one, where the aromatic benzaldehyde had an electron-withdrawing group.\u0000\u0000\u0000\u0000Substituted benzaldehyde gave better yields than benzaldehyde. And nitro group which is electrowithdrawing attached to benzaldehyde enhanced the electrophilic nature at carbonyl center showed higher yields than methoxy group which is electron donating attached to benzaldehyde as it deactivates the carbonyl carbon. The polar protic solvents like water, ethanol and methanol stabilizes the ionic intermediates and gave better yield. Even the moderately apolar solvents like DCM, chloroform resulted in good yields, green solvents like water, ethanol and methanol would be a better choice as solvents. The carbon chain on the solvent has got an effect on product yield. As the carbon chain increases in solvent, the yield decreases due to the separation difficulties. The polar aprotic solvents did gave better yields but not as good as polar protic solvents.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44654914","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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