Pub Date : 2023-08-21DOI: 10.3390/reactions4030026
E. Leyva, Silvia E. Loredo-Carrillo, Johana Aguilar
Nitrated products are important since they are intermediates in the synthesis of other compounds, such as explosives, perfumes, dyes and plastics, among others, and they have an easy capacity to convert into other functional groups. The synthesis of compounds with biological activity that have a nitro group in their structure is relevant to improving and/or enhancing their effect. In this work, different methodologies for the nitration of naphthoquinone derivative compounds are presented. The nitration of 3-R-2-(phenylamino)-1,4-naphthoquinone derivatives was carried out with nitric acid and sulfuric acid; milder reaction conditions were also established by diluting the acids or performing the reaction with weaker acids. Other methodologies were tested using nitrate salts for mononitrate product synthesis. We used a solvent-free reaction with oxalic acid using 3-R-2-(phenylamino)-1,4-naphthoquinones (R=H, Br or Cl), noting that the electronegativity of the chlorine group is decisive for achieving nitration with good yields. Finally, a Michael addition was performed with some nitrated anilines. To obtain denitrated compounds in the ortho and para positions, the reaction with strong acids is feasible; however, for the formation of mononitrated products, the Michael-type addition is more convenient.
{"title":"Various Techniques for the Synthesis of 2-Nitrophenylamino-1,4-naphthoquinone Derivatives","authors":"E. Leyva, Silvia E. Loredo-Carrillo, Johana Aguilar","doi":"10.3390/reactions4030026","DOIUrl":"https://doi.org/10.3390/reactions4030026","url":null,"abstract":"Nitrated products are important since they are intermediates in the synthesis of other compounds, such as explosives, perfumes, dyes and plastics, among others, and they have an easy capacity to convert into other functional groups. The synthesis of compounds with biological activity that have a nitro group in their structure is relevant to improving and/or enhancing their effect. In this work, different methodologies for the nitration of naphthoquinone derivative compounds are presented. The nitration of 3-R-2-(phenylamino)-1,4-naphthoquinone derivatives was carried out with nitric acid and sulfuric acid; milder reaction conditions were also established by diluting the acids or performing the reaction with weaker acids. Other methodologies were tested using nitrate salts for mononitrate product synthesis. We used a solvent-free reaction with oxalic acid using 3-R-2-(phenylamino)-1,4-naphthoquinones (R=H, Br or Cl), noting that the electronegativity of the chlorine group is decisive for achieving nitration with good yields. Finally, a Michael addition was performed with some nitrated anilines. To obtain denitrated compounds in the ortho and para positions, the reaction with strong acids is feasible; however, for the formation of mononitrated products, the Michael-type addition is more convenient.","PeriodicalId":20873,"journal":{"name":"Reactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82872772","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 : 2023-08-04DOI: 10.3390/reactions4030025
Nothando C. Shiba, Xinying Liu, Yali Yao
The effect of the different supports and catalyst-reducing agents on the Fischer–Tropsch (FT) reaction was investigated. The large surface area SiO2 support with a smaller pore volume deposited fine, evenly distributed Co3O4. Cubic-shaped Co3O4 appeared in clusters on the TiO2 support, whereas Co3O4 existed as single large particles on the Al2O3 support. The activity data obtained were discussed in terms of cluster size, particle size, particle shape, and mass transport limitations. The SiO2-supported catalysts showed a higher activity for the formation of paraffinic products when reduced in H2 at 250 °C. This is attributed to the formation of the CoO-Co active bond, which enhanced the activation of CO and the hydrogenation reactions. A higher activity was observed for the TiO2-supported catalyst at a higher reduction temperature (350 °C) when the mass of Co metal was higher. It afforded more paraffinic products due to enhanced secondary hydrogenation of olefins at higher reaction rates. The large Co3O4 supported on Al2O3 showed the least activity at both reduction temperatures due to strong metal-support interactions. The H2-reduced catalysts exhibited superior activity compared to all the syngas-reduced catalysts. Syngas reduction led to surface carbon deposition and the formation of surface carbides which suppressed the hydrogenation reactions and are selective to olefinic products.
{"title":"Insight into the Physicochemical Properties of Co-Based Catalysts in Fischer–Tropsch Synthesis","authors":"Nothando C. Shiba, Xinying Liu, Yali Yao","doi":"10.3390/reactions4030025","DOIUrl":"https://doi.org/10.3390/reactions4030025","url":null,"abstract":"The effect of the different supports and catalyst-reducing agents on the Fischer–Tropsch (FT) reaction was investigated. The large surface area SiO2 support with a smaller pore volume deposited fine, evenly distributed Co3O4. Cubic-shaped Co3O4 appeared in clusters on the TiO2 support, whereas Co3O4 existed as single large particles on the Al2O3 support. The activity data obtained were discussed in terms of cluster size, particle size, particle shape, and mass transport limitations. The SiO2-supported catalysts showed a higher activity for the formation of paraffinic products when reduced in H2 at 250 °C. This is attributed to the formation of the CoO-Co active bond, which enhanced the activation of CO and the hydrogenation reactions. A higher activity was observed for the TiO2-supported catalyst at a higher reduction temperature (350 °C) when the mass of Co metal was higher. It afforded more paraffinic products due to enhanced secondary hydrogenation of olefins at higher reaction rates. The large Co3O4 supported on Al2O3 showed the least activity at both reduction temperatures due to strong metal-support interactions. The H2-reduced catalysts exhibited superior activity compared to all the syngas-reduced catalysts. Syngas reduction led to surface carbon deposition and the formation of surface carbides which suppressed the hydrogenation reactions and are selective to olefinic products.","PeriodicalId":20873,"journal":{"name":"Reactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78856961","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 : 2023-08-03DOI: 10.3390/reactions4030024
V. Protsenko
A literature review was conducted to examine the current understanding of the kinetics and mechanism of electrochemical reactions occurring during the electrodeposition of chromium coatings from electrolytes based on trivalent chromium compounds. The research in this scientific field is crucial, as it addresses the pressing need for an alternative to chromium plating processes that rely on solutions containing highly toxic and harmful hexavalent chromium compounds. Numerous literature data on the kinetics and mechanism of the stepwise reduction process of Cr(III) complex ions were analyzed. The influence of various additives and surfactants on the reaction kinetics of the stepwise reduction of trivalent chromium ions was considered. Special attention was given to the kinetics of the stepwise discharge of trivalent chromium ions in ionic liquids and deep eutectic solvents.
{"title":"Kinetics and Mechanism of Electrochemical Reactions Occurring during the Chromium Electrodeposition from Electrolytes Based on Cr(III) Compounds: A Literature Review","authors":"V. Protsenko","doi":"10.3390/reactions4030024","DOIUrl":"https://doi.org/10.3390/reactions4030024","url":null,"abstract":"A literature review was conducted to examine the current understanding of the kinetics and mechanism of electrochemical reactions occurring during the electrodeposition of chromium coatings from electrolytes based on trivalent chromium compounds. The research in this scientific field is crucial, as it addresses the pressing need for an alternative to chromium plating processes that rely on solutions containing highly toxic and harmful hexavalent chromium compounds. Numerous literature data on the kinetics and mechanism of the stepwise reduction process of Cr(III) complex ions were analyzed. The influence of various additives and surfactants on the reaction kinetics of the stepwise reduction of trivalent chromium ions was considered. Special attention was given to the kinetics of the stepwise discharge of trivalent chromium ions in ionic liquids and deep eutectic solvents.","PeriodicalId":20873,"journal":{"name":"Reactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82830715","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 : 2023-07-19DOI: 10.3390/reactions4030023
I. Bilera
During high-temperature pulse pyrolysis of acyclic butanes and pentanes under adiabatic compression conditions, cyclopropane, a stressed cyclic hydrocarbon, was found among the reaction products in small quantities for the first time. The analysis of the reaction products was performed by gas chromatography using three capillary columns of different polarity, selectivity and sufficient efficiency. The identification of reaction products, including cyclopropane, was performed using retention times of individual substances and model mixtures, as well as comparing chromatograms with reference chromatograms from the literature and the ScanView Application Database. It was shown that the chromatographic peak attributed to cyclopropane could not be a ghost peak. Additional confirmation of this conclusion was obtained in a series of experiments on the pyrolysis of n-butane at a reduced initial temperature of the adiabatic compression reactor (from 120 °C to 50 °C) and a modified mode of GC analysis. Cyclopropane yields as a function of maximum temperature have a bell-shaped asymmetric dependence. The maximum value of the yield of cyclopropane increases with the transition from normal alkanes to isoalkanes, and from pentanes to butanes; for n-pentane, 0.009 wt. %, and for isobutene, ≈0.017 wt. %. During the pulse pyrolysis of isobutane, n-butane, isopentane and n-pentane, cyclopropane is not a primary product. Further theoretical and experimental studies are needed to establish the mechanism of cyclopropane formation during pyrolysis of C4–C5 acyclic alkanes.
{"title":"The Formation of Small Amounts of Cyclopropane during Pulsed Pyrolysis of C4–C5 Acyclic Alkanes in the Adiabatic Compression Reactor","authors":"I. Bilera","doi":"10.3390/reactions4030023","DOIUrl":"https://doi.org/10.3390/reactions4030023","url":null,"abstract":"During high-temperature pulse pyrolysis of acyclic butanes and pentanes under adiabatic compression conditions, cyclopropane, a stressed cyclic hydrocarbon, was found among the reaction products in small quantities for the first time. The analysis of the reaction products was performed by gas chromatography using three capillary columns of different polarity, selectivity and sufficient efficiency. The identification of reaction products, including cyclopropane, was performed using retention times of individual substances and model mixtures, as well as comparing chromatograms with reference chromatograms from the literature and the ScanView Application Database. It was shown that the chromatographic peak attributed to cyclopropane could not be a ghost peak. Additional confirmation of this conclusion was obtained in a series of experiments on the pyrolysis of n-butane at a reduced initial temperature of the adiabatic compression reactor (from 120 °C to 50 °C) and a modified mode of GC analysis. Cyclopropane yields as a function of maximum temperature have a bell-shaped asymmetric dependence. The maximum value of the yield of cyclopropane increases with the transition from normal alkanes to isoalkanes, and from pentanes to butanes; for n-pentane, 0.009 wt. %, and for isobutene, ≈0.017 wt. %. During the pulse pyrolysis of isobutane, n-butane, isopentane and n-pentane, cyclopropane is not a primary product. Further theoretical and experimental studies are needed to establish the mechanism of cyclopropane formation during pyrolysis of C4–C5 acyclic alkanes.","PeriodicalId":20873,"journal":{"name":"Reactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81904449","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 : 2023-07-15DOI: 10.3390/reactions4030022
L. Sineva, V. Mordkovich, E. Asalieva, V.Ye. Smirnova
The review is dedicated to the topical field of research aimed at creating catalysts combining several types of active sites. At the same time, the composition of Fischer–Tropsch synthesis (FTS) products can be controlled by changing the strength and concentration of the active sites and inter-site distances. A comparative analysis of the literature data allows to formulate the main principles of catalytic particles formation active in FTS and acid-catalyzed transformations of hydrocarbons: (1) the presence of weak Bronsted acid sites to control the cracking depth, (2) an availability of Bronsted acid sites for re-adsorption hydrocarbons and (3) weak Co-zeolite interaction to reduce methane formation.
{"title":"Zeolite-Containing Co Catalysts for Fischer–Tropsch Synthesis with Tailor-Made Molecular-Weight Distribution of Hydrocarbons","authors":"L. Sineva, V. Mordkovich, E. Asalieva, V.Ye. Smirnova","doi":"10.3390/reactions4030022","DOIUrl":"https://doi.org/10.3390/reactions4030022","url":null,"abstract":"The review is dedicated to the topical field of research aimed at creating catalysts combining several types of active sites. At the same time, the composition of Fischer–Tropsch synthesis (FTS) products can be controlled by changing the strength and concentration of the active sites and inter-site distances. A comparative analysis of the literature data allows to formulate the main principles of catalytic particles formation active in FTS and acid-catalyzed transformations of hydrocarbons: (1) the presence of weak Bronsted acid sites to control the cracking depth, (2) an availability of Bronsted acid sites for re-adsorption hydrocarbons and (3) weak Co-zeolite interaction to reduce methane formation.","PeriodicalId":20873,"journal":{"name":"Reactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87666205","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 : 2023-07-04DOI: 10.3390/reactions4030021
A. A. Mohana, M. Rahman, Md. Hafezur Rahaman, M. Maniruzzaman, S. Farhad, Md Meftaul Islam, Md. Sirajul Islam Khan, Md. Zahid Parvez
Water pollution by contaminants such as toxic metals and dyes is now a major concern due to their high toxicity and persistence in the environment. Advances in nanotechnology have enabled the use of micro/nanomaterials to treat and purify water in various industries. In this study, Bijoypur clay was modified with ethyldiamine and incorporated into an okra fiber (Abelmoschus esculentus) micro-cellulose crystal (MCC) to produce a composite that could absorb copper (Cu), nickel (Ni), and dyes like basic yellow (II) from industrial wastewater. Composites were prepared using different percentages of MCC and clay. Atomic absorption spectroscopy (AAS) was used to determine the concentrations of Cu and Ni whereas a UV–Visible spectrophotometer measured the absorbance of basic yellow (II). The synthesized composites were extensively characterized using a range of techniques including thermogravimetry (TG) and differential thermogravimetry (DTG), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Results show that both the MCC and clay could absorb Cu, Ni, and basic yellow (II) from the contaminated wastewater. The MCC and clay composite showed the maximum efficiency of metals removal, which was up to 95% (24 mg/g) for Cu at pH 6, 20 min contact time, 2 g/L adsorbent dose, and 100% (31 mg/g) for Ni at pH 8, 60 min contact time, and 2 g/L adsorbent dose, respectively, at the initial concentration of 50 mg/L. The maximum dye uptake capacity of 85% (19 mg/g) was observed by the MCC and clay composite under optimized conditions at the initial concentration of 50 mg/L, pH 8, 30 min contact time, and 1 g/L adsorbent dose compared to the pure clay, which had an efficiency up to 26% for Cu and 24% for dye removal. All of the results indicate that incorporating clay into MCC increases the absorption capacity of contaminants from wastewater, which could be more effective for environmental applications compared to untreated cellulose.
{"title":"Okra Micro-Cellulose Crystal (MCC) and Micro-Clay Composites for the Remediation of Copper, Nickel, and Dye (Basic Yellow II) from Wastewater","authors":"A. A. Mohana, M. Rahman, Md. Hafezur Rahaman, M. Maniruzzaman, S. Farhad, Md Meftaul Islam, Md. Sirajul Islam Khan, Md. Zahid Parvez","doi":"10.3390/reactions4030021","DOIUrl":"https://doi.org/10.3390/reactions4030021","url":null,"abstract":"Water pollution by contaminants such as toxic metals and dyes is now a major concern due to their high toxicity and persistence in the environment. Advances in nanotechnology have enabled the use of micro/nanomaterials to treat and purify water in various industries. In this study, Bijoypur clay was modified with ethyldiamine and incorporated into an okra fiber (Abelmoschus esculentus) micro-cellulose crystal (MCC) to produce a composite that could absorb copper (Cu), nickel (Ni), and dyes like basic yellow (II) from industrial wastewater. Composites were prepared using different percentages of MCC and clay. Atomic absorption spectroscopy (AAS) was used to determine the concentrations of Cu and Ni whereas a UV–Visible spectrophotometer measured the absorbance of basic yellow (II). The synthesized composites were extensively characterized using a range of techniques including thermogravimetry (TG) and differential thermogravimetry (DTG), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Results show that both the MCC and clay could absorb Cu, Ni, and basic yellow (II) from the contaminated wastewater. The MCC and clay composite showed the maximum efficiency of metals removal, which was up to 95% (24 mg/g) for Cu at pH 6, 20 min contact time, 2 g/L adsorbent dose, and 100% (31 mg/g) for Ni at pH 8, 60 min contact time, and 2 g/L adsorbent dose, respectively, at the initial concentration of 50 mg/L. The maximum dye uptake capacity of 85% (19 mg/g) was observed by the MCC and clay composite under optimized conditions at the initial concentration of 50 mg/L, pH 8, 30 min contact time, and 1 g/L adsorbent dose compared to the pure clay, which had an efficiency up to 26% for Cu and 24% for dye removal. All of the results indicate that incorporating clay into MCC increases the absorption capacity of contaminants from wastewater, which could be more effective for environmental applications compared to untreated cellulose.","PeriodicalId":20873,"journal":{"name":"Reactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84568823","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 : 2023-06-21DOI: 10.3390/reactions4030020
Vladimir V. Kouznetsov, Daniela Calderón Lamus, Carlos E. Puerto Galvis
We hereby describe an efficient method for the preparation of a series of new 1-substituted 1,2,3-triazole-based acetaminophen derivatives through a clean, good-yielding, simple, and expeditious procedure based on the O-propargylation reaction of the acetaminophen (APAP) obtained from expired commercial tablets and the CuBr(PPh3)3-catalyzed Huisgen reaction between O-propargylated APAP and diverse organoazides prepared from commercially available anilines as available starting reagents. An interesting nitric oxide-releasing 1,2,3-triazole hybrid of APAP was also obtained easily using the developed method. The structures of the designed hybrid compounds, which are expected to be pharmacologically active, were characterized by FT-IR, 1H-, and 13C-NMR and are reported for the first time. According to the in-silico ADMET prediction studies performed in this work and literature analysis, these hybrids are interesting models in search of new pharmacological nontoxic agents endowed with anti-inflammatory and anticancer properties.
{"title":"Synthesis and Characterization of New Functionalized 1,2,3-Triazole-Based Acetaminophen Derivatives via Click Chemistry from Expired Commercial Acetaminophen Tablets","authors":"Vladimir V. Kouznetsov, Daniela Calderón Lamus, Carlos E. Puerto Galvis","doi":"10.3390/reactions4030020","DOIUrl":"https://doi.org/10.3390/reactions4030020","url":null,"abstract":"We hereby describe an efficient method for the preparation of a series of new 1-substituted 1,2,3-triazole-based acetaminophen derivatives through a clean, good-yielding, simple, and expeditious procedure based on the O-propargylation reaction of the acetaminophen (APAP) obtained from expired commercial tablets and the CuBr(PPh3)3-catalyzed Huisgen reaction between O-propargylated APAP and diverse organoazides prepared from commercially available anilines as available starting reagents. An interesting nitric oxide-releasing 1,2,3-triazole hybrid of APAP was also obtained easily using the developed method. The structures of the designed hybrid compounds, which are expected to be pharmacologically active, were characterized by FT-IR, 1H-, and 13C-NMR and are reported for the first time. According to the in-silico ADMET prediction studies performed in this work and literature analysis, these hybrids are interesting models in search of new pharmacological nontoxic agents endowed with anti-inflammatory and anticancer properties.","PeriodicalId":20873,"journal":{"name":"Reactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135045411","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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