scholarly journals New method for synthesis of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropylthiocarbamates by oxidation of ammonium salt of xhantogenic acid

2010 ◽  
Vol 64 (5) ◽  
pp. 401-409 ◽  
Author(s):  
Smiljka Milisavljevic ◽  
Aleksandar Marinkovic ◽  
Milutin Milosavljevic
Keyword(s):  
Hydrogen Peroxide ◽  
Ammonium Salt ◽  
Sodium Hypochlorite ◽  
Reaction Times ◽  
Synthetic Methods ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Optimal Method ◽  
Sodium Ethyl ◽  
Industrial Level

A synthesis of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates by oxidation of ammonium salt of ethyl and isopropylxanthogenic acid in a presence of sodium hypochlorite and hydrogen peroxide were performed. Ammonium salt of ethyl and isopropylxanthogenic acid was obtained by the reaction of alkylammonium sulfate and sodium ethyl and isopropyl xanthate. Studies on a dependence of N-ethyl-O-isopropylthiocarbamate yield and purity with respect to reaction parameters (reaction time, molar ratio of oxidant and ethylamonium salt of isopropylxanthogenic acid) were performed. Optimal reaction conditions for synthesis of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates were established. Synthesized compounds have been fully characterized by FTIR, 1H NMR and MS data, while purity has been determined by GC method. A plausible pathway for the N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates synthesis, in the presence of the oxidative agents sodium hypochlorite and hydrogen peroxide, was proposed. The presented synthetic methods has been developed at laboratory and applied at semi-industrial level. The developed optimal method provides a powerful and versatile method for the preparation of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates. This new optimized method offer several benefits, namely, simple operation, mild reaction conditions, bypass of hazardous organic solvents, moderately toxic and inexpensive reagents, and also short reaction times and high product yields.

scholarly journals Simple one-pot synthesis of thioureas from amine, carbon disulfide and oxidants in water

2016 ◽  
Vol 81 (3) ◽  
pp. 219-231 ◽  
Author(s):  
Milutin Milosavljevic ◽  
Ivan Vukicevic ◽  
Sasa Drmanic ◽  
Jasmina Nikolic ◽  
Aleksandar Marinkovic ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Disulfide ◽  
Reaction Times ◽  
Tetraacetic Acid ◽  
Reaction Conditions ◽  
One Pot ◽  
1H And 13C Nmr ◽  
Industrial Level ◽  
By Products ◽  
Operational Simplicity

The present study reports the new facile methodology for synthesis of symmetrical and asymmetrical thioureas by an one-pot reaction of amine, carbon disulfide and oxidants: hydrogen peroxide, ethylenediamine tetraacetic acid (EDTA)/sodium percarbonate system or air. The structures of the synthesized compounds were confirmed by IR, 1H and 13C NMR and MS methods. Reaction mechanism has been proposed on the basis of reaction intermediate isolation and their structure determination. The synthetic benefits of the presented methods is reflected in the operational simplicity, mild reaction conditions, short reaction times, recycling of solvent, high purity and yield of products, absence of dangerous by-products and technological applicability at industrial scale. Considering commercial importance of the thioureas, it can be emphasized that implementation of the optimal synthesis of thiourea, based on presented methods, at industrial level of production would provide concurrent alternative to existing technologies in use.

Efficient synthesis of pyrido[2,3-d]pyrimidine-7-carboxylic acids catalyzed by a TiO2/SiO2 nanocomposite in aqueous media at room temperature

2018 ◽  
Vol 73 (9) ◽  
pp. 641-645 ◽  
Author(s):  
Sepehr Sadegh-Samiei ◽  
Shahrzad Abdolmohammadi
Keyword(s):  
Heterogeneous Catalyst ◽  
Carboxylic Acids ◽  
Room Temperature ◽  
Aqueous Media ◽  
Reaction Times ◽  
Molar Ratio ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Moderate Reaction ◽  
Recyclable Heterogeneous Catalyst

AbstractA novel and efficient synthesis of eight 5-aryl-1,3-dimethyl-2,4-dioxo-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids using a TiO2/SiO2 nanocomposite with a molar ratio of 1:1 as a recyclable heterogeneous catalyst is described. The desired products, five of which are new, are formed in short reaction times (2–3 h) with high to excellent yields (94%–98%) under very moderate reaction conditions (room temperature, aqueous media).

scholarly journals Optimization of the Lipase Catalyzed Production of Structured Acylglycerols With Polyunsaturated Fatty Acids Isolated From Sardine Oil

2013 ◽  
Vol 2 (6) ◽  
pp. 97 ◽  
Author(s):  
Juan Antonio Noriega-Rodriguez ◽  
Esther Carrillo-Perez ◽  
Nohemi Gamez-Meza ◽  
Luis A. Medina-Juarez ◽  
Ramiro Baeza-Jimenez ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Immobilized Lipase ◽  
Reaction Times ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Molar Ratios ◽  
Sardine Oil ◽  
Different Temperatures ◽  
Urea Crystallization

<p>In the present work, direct enzyme-catalyzed esterification of n-3 polyunsaturated fatty acids (n-3 PUFA) isolated from sardine oil was optimized to obtain structured acyglycerols. A n-3 PUFA concentrate was prepared by urea crystallization of refined sardine oil and esterification was carried out mixing free fatty acids and glycerol at different molar ratios (<em>M</em> = 0.48, 1.5, 3.0, 4.5 and 5.52 mol/mol), using an immobilized lipase preparation from <em>Candida antarctica</em> (NV-435) at different temperatures (<em>T</em> = 38, 45, 55, 65 and 72 °C) and reaction times (<em>t</em> = 0.7, 2.75, 5.75, 8.75 and 10.8 h) in a rotatable central composition design. The degree of esterification was determined by analysis of the acylglycerides produced, using liquid chromatography (HPLC-ELSD). Optimization by response surface methodology (RSM) showed that in order to obtain higher esterification levels of n-3 PUFA to glycerol (99.5%), a molar ratio of 1.3 mol n-3 PUFA/mol glycerol, time 8.3 h and temperature 38 °C, are required. However, results of this work show that it is possible to drive the reaction to any determined product (MAG, DAG or TAG) by modifying the reaction conditions.</p>

scholarly journals Comparative analysis of oxidative synthesis of N-alkyl, N,N-dialkyl and N-cykloalkyl-O-isobutyl thioncarbamate

2011 ◽  
Vol 65 (5) ◽  
pp. 541-549 ◽  
Author(s):  
Milica Sovrlic ◽  
Milutin Milosavljevic ◽  
Aleksandar Marinkovic ◽  
Jasmina Djukanovic ◽  
Danijela Brkovic ◽  
...  
Keyword(s):  
Molar Ratio ◽  
Scale Production ◽  
Reaction Conditions ◽  
1H And 13C Nmr ◽  
Comparative Results ◽  
Industrial Level ◽  
Gas Chromatographic Method ◽  
First Time ◽  
Optimal Reaction ◽  
Yield And Purity

A optimized synthesis of N-alkyl, N,N-dialkyl- and N-cycloalkyl-O-isobutyl thioncarbamates by aminolysis of sodium isobutylxanthogenic acid (NaiBXAc) and primary, secondary and cycloalkyl amines was developed at laboratory scale and applied at semi-industrial level. Studies on dependence of N-n-propyl-O-isopropylthiocarbamate yield and purity with respect to reaction parameters: reaction time and molar ratio of n-propylamine and NaiBXAc, were performed. In such way, optimal reaction conditions for synthesis of N-alkyl, N,N-dialkyl- and N-cycloalkyl-O-isobutyl thioncarbamates, by aminolysis of NaiBXAc, were established. Also, comparative results of thioncarbamates synthesis starting from potassium isobutyl xanthate (KiBX) and corresponding amines in presence of different oxidants: hydrogen peroxide, sodium hypochlorite and new oxidative agent potassium peroxodisulfate were evaluated. Synthesized compounds have been fully characterized by FTIR, 1H and 13C NMR and MS data, elemental analysis and purity have been determined by gas chromatographic method (GC). According to our knowledge, ten synthesized thioncarbamates are for the first time characterized. Synthesized compounds could be used as selective reagents for flotation of copper and zinc ores. The presented methods offer several benefits, namely, high product yields and purity, simple operation, mild reaction conditions without use of hazardous organic solvents, while some of them could be implemented on industrial scale production.

Synthese und Eigenschaften von N-phosphorylierten Aminomethylen-dimethylphosphinoxiden und -sulfiden / Synthesis and Properties of N-Phosphorylated Aminomethylene-Dimethylphosphine Oxides and -Sulfides

1995 ◽  
Vol 50 (12) ◽  
pp. 1818-1832 ◽  
Author(s):  
Thomas Kaukorat ◽  
Ion Neda ◽  
Reinhard Schmutzler
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphorus Atom ◽  
Addition Product ◽  
Molar Ratio ◽  
Oxidizing Agent ◽  
Reaction Conditions

In the reaction of N-methylaminomethylene-dimethylphosphine oxide and sulfide with diethylaminotrimethylsilane, N-methyl-N-trimethylsilyl-aminomethylene-dimethylphosphine oxide (1) and sulfide (2) were formed. These compounds were allowed to react with a series of P(III)C1 compounds to give the corresponding methylaminomethylene-bridged diphosphorus compounds (3 - 10) with phosphorus in the combination λ4P(V)/λ3P(III). In the oxidation of some of these compounds by the hydrogen peroxide-urea 1:1-adduct (NH2)2CO ·H2O2 or sulfur, the corresponding λ4P-CH2-N(Me)-λ4P-derivatives (11 - 16) were formed. Different reaction behaviour was observed depending on the substituent at λ4P or on the oxidizing agent. Reaction of 1 with trimethylsilylmethyl tetrafiuorophosphorane and with bromotriphenylphosphonium bromide furnished, besides trimethylhalosilane, the corresponding diphosphorus compounds (17 ) and (18) with phosphorus in the combination λ4P(V)/λ5P(V) (17) and λ4P(V)/λ4P(V)+ (18).Oxidation of N-diphenylphosphino-N-methyl-aminomethylene-dimethylphosphine oxide (3) by tetrachloro-o-benzoquinone led to the corresponding addition product in impure form. Reaction of 3 with hexafluoroacetone (HFA) yielded a mixture of two products which could not be separated. Both oxidation (>N-PPh2 → >N-P(:O)Ph2) and insertion of HFA into the P-N-bond (>N-PPh2 → >NC(CF3)2-O-PPh2) occurred. In the reaction of 1 with methyldichlorophosphine, both the mono- and disubstituted products, 22 and 23, were formed, independently of the reaction conditions and molar ratio of the starting compounds. The reaction of 1 with bis(diethylamino)chlorophosphine was unusual. Upon separation of both trimethylchlorosilane and dimethylaminotrimethylsilane, compounds 24 - 26 were formed, with the central phosphorus atom bearing one, two or three methylaminomethylene-dimethylphosphine oxide groups, respectively. Simultaneously, tris(diethylamino)phosphine was formed.

Iodination of Organic Compounds with Elemental Iodine in the Presence of Hydrogen Peroxide in Ionic Liquid Media

2008 ◽  
Vol 61 (12) ◽  
pp. 946 ◽  
Author(s):  
Jasminka Pavlinac ◽  
Kenneth K. Laali ◽  
Marko Zupan ◽  
Stojan Stavber
Keyword(s):  
Hydrogen Peroxide ◽  
Ionic Liquid ◽  
Organic Compounds ◽  
Molar Ratio ◽  
Liquid Media ◽  
Reaction Conditions ◽  
Solid Form ◽  
Elemental Iodine ◽  
Solvent Free Reaction

Iodo-transformations using the reagent system I2/H2O2 were studied in the water miscible ionic liquid (IL) 1-butyl-3-methyl imidazolium tetrafluoroborate (bmimBF4) and in water immiscible IL, 1-butyl-3-methyl imidazolium hexafluorophosphate (bmimPF6). Two different forms of H2O2 as mediators of iodination were investigated, namely 30% aq. H2O2 and urea-H2O2 (UHP) in solid form. The role of the oxidant during the course of a reaction could be distinguished based on the amount of reagent required for the most efficient transformation. Two types of iodo-functionalizations through an electrophilic process were observed depending on the structure of the substrates. Whereas ring iodination took place in the case of dimethoxy- and trimethoxy-benzenes, with arylalkyl ketones the alkyl group α to the carbonyl was regioselectively iodinated. The results were further evaluated in comparison with iodination using the reagent system I2/H2O2 in water as medium, and under solvent-free reaction conditions, in terms of efficiency, selectivity, mechanism, and the ‘green’ aspects. The reusability/recycling of water immiscible bmimPF6 was investigated for 1,3,5-trimethoxy benzene (1b), which required a 1/0.5/0.6 molar ratio of substrat/I2/oxidant, and for 1,2,3-trimethoxy benzene (1f), which required a 1/1/1 ratio for complete iodine introduction. In addition, the efficiency of iodination was tested by varying the substrates, and employing the recycled hydrophobic IL bmimPF6.

Research on Synthesis Regularity of Epoxysuccinic Acid

2013 ◽  
Vol 316-317 ◽  
pp. 942-945
Author(s):  
Qing He Gao ◽  
Yi Can Wang ◽  
Zhi Feng Hou ◽  
Hui Juan Qian ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Maleic Anhydride ◽  
Reaction Temperature ◽  
Raw Material ◽  
Molar Ratio ◽  
Mass Ratio ◽  
Synthesis System ◽  
Reaction Conditions ◽  
Sodium Hydrate

The yield of epoxysuccinic acid was obtained by determining the content of unreacted maleic anhydride and tartaric acid as a by-product in synthesis system. This method could calculate the yield of epoxysuccinic acid precisely and overcome the disadvantage of obtaining inpure product by recrystallization method. Epoxysuccinic Acid was synthesized using maleic anhydride as raw material, hydrogen peroxide as oxidizer and tungstate as catalyst. The effects of reaction temperature, reaction time, ratio of materials, dosage of oxidizer and catalyst on epoxidation and hydrolysis reaction was investigated. The results showed that the yield of epoxysuccinic acid was 88% when the reaction conditions were as follows: reaction temperature 65°C, reaction time 1.5h, catalyst dosage 3%(based on mass of maleic anhydride), molar ratio of sodium hydrate to maleic anhydride 2:1, mass ratio of hydrogen peroxide to maleic anhydride 1:1.

scholarly journals Production of biodiesel by esterification and transesterification from waste cooking oils

2020 ◽  
Vol 38 (1) ◽  
pp. 105-127
Author(s):  
Elsy Arenas ◽  
Aidin Urribarrí ◽  
John Sánchez ◽  
Marisela Rincón ◽  
Karina Martínez ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Fast Food ◽  
Methyl Esters ◽  
Reaction Times ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Waste Cooking Oils ◽  
Hcl Concentration ◽  
Cooking Oils

Large quantities of used vegetable oils (AVUs) are generated annually, as a result of food preparation, which can cause contamination of waters and soils, if they are not disposed of properly, but in turn have great potential in the production of biodiesel. In this work, the AVU collected from fast food establishments were subjected to an esterification pretreatment, varying the reaction conditions, molar ratio, catalyst concentration and time, to decrease the content of free fatty acids generated in the frying processes; after an alkaline transesterification. The initial acidity of the AVUs (10,08 ± 0,22 %) was found to drop below 1 % during esterification at 60 °C and 100 rpm, with RMAVU:MeOH of 1: 7 and HCl concentration of 0.3 % v/v, with a conversion of free fatty acids (FFA) to methyl esters of 94.48 and 98.61 % for reaction times of 4 and 6 hours, respectively. The previously esterified AVUs were subjected to a transesterification process with KOH as a catalyst in the presence of methanol, at 60 °C and 100 rpm, finding that the biodiesel produced was a mixture composed of the methyl esters of linoleic acids (57 %), palmitic (14 %), oleic (22 %), stearic (4 %) and elaidic (3 %). The highest concentration of methyl esters (93,797 ± 0.685 g.L-1) was obtained when using the esterified AVU during 6 hours of reaction. FTIR spectra confirmed the conversion of fatty acids to methyl esters, so this product could be used as a biofuel.

scholarly journals Oxidative Desulfurization of Diesel Fuel Using Three Kinds of Carboxylic Acids Supported by Iron(III) Chloride

2021 ◽  
Vol 11 (1) ◽  
pp. 104-111
Author(s):  
Jalil H. Kareem
Keyword(s):  
Hydrogen Peroxide ◽  
Carboxylic Acids ◽  
Diesel Fuel ◽  
Sulfur Removal ◽  
Oxidative Desulfurization ◽  
Reaction Times ◽  
Petroleum Products ◽  
Molar Ratio ◽  
Similar Reaction ◽  
Hydrotreated Diesel

Aqueous carboxylic acids (CA) are generally used as attractive catalytic extractants in the field of desulfurization of petroleum products. In the present study, a triple system consisting of CA-ferric chloride-hydrogen peroxide has been used for the removal of aromatic S-compounds from partially hydrotreated diesel by liquid−liquid oxidative-extraction. The influence of various operating parameters affecting the oxidative desulfurization was experimentally investigated. Formic acid (HCOOH), acetic acid (CH3COOH), and propanoic acid (CH3CH2COOH) as aqueous solutions with hydrogen peroxide and iron(III) chloride (FeCl3) as oxidant and catalytic agent, respectively, were used. All experiments were carried out at 55°C with different oxidant to sulfur mole ratios (nH2O2/nS) (15–36), CA to sulfur mole ratios (nCA/nS) (2–26), and oxidation reaction times (5–25 min). Within 25 min of the treatment, a maximum elimination of aromatic S-compounds of 65.1% was obtained when molar ratio of oxidant to sulfur (nH2O2/nS) was 36 and molar ratio of CA to sulfur (nCA/nS) was 26. Surface tension calculations for the CAs demonstrated that the average void radius of the acids has a pronounced effect on the fitting of S-compounds from diesel fuel into acids and is important to sulfur removal. Further, increasing the desulfurization efficiency was also energetically affected in the presence of ferric halide. The obtention of the sulfur removal ability value was noticeably higher than was achieved by employing similar reaction conditions in the absence of FeCl3.

Synthesis of Phosphonates via Michaelis-Arbuzov Reaction

2017 ◽  
Vol 14 (6) ◽  
pp. 883-903 ◽  
Author(s):  
Boppudi Hari Babu ◽  
Gandavaram Syam Prasad ◽  
Chamarthi Naga Raju ◽  
Mandava Venkata Basaveswara Rao
Keyword(s):  
Reaction Times ◽  
Biologically Active ◽  
Fine Tuning ◽  
Arbuzov Reaction ◽  
Reaction Conditions ◽  
Solvent Type ◽  
Potential Applications ◽  
Synthetic Methodologies ◽  
Optimal Reaction ◽  
The Arbuzov Reaction

Background: Michaelis–Arbuzov reaction has played a key role for the synthesis of dialkyl or diaryl phosphonates by reacting various alkyl or aryl halides with trialkyl or triaryl phosphite. This reaction is very versatile in the formation of P-C bond from the reaction of aliphatic halides with phosphinites or phosphites to yield phosphonates, phosphinates, phosphine oxides. The Arbuzov reaction developed some methodologies, possible mechanistic pathways, selectivity, potential applications and biologically active various phosphonates. Objective: The synthesis of phosphonates via Michaelis–Arbuzov reaction with many new and fascinating methodologies were developed and disclosed in the literature, and these are explored in this review. Conclusion: This review has discussed past developments and vast potential applications of Arbuzov reaction in the synthesis of organophosphonates. As presented in this review, various synthetic methodologies were developed to prepare a large variety of phosphonates. Improvements in the reaction conditions of Lewis-acid mediated Arbuzov rearrangement as well as the development of MW-assisted Arbuzov rearrangement were discussed. Finally, to achieve high selectivities and yields, fine-tuning of reaction conditions including solvent type, temperature, and optimal reaction times to be considered.

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