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.

Lipase-Catalyzed Acyl-L-Carnitines Synthesis in [Bmim]PF6 Ionic Liquid

2009 ◽  
Vol 5 (1) ◽  
Author(s):  
Jin-qiang Tian ◽  
Qiang Wang ◽  
Zhong-yuan Zhang
Keyword(s):  
Ionic Liquid ◽  
Lipase Activity ◽  
Molecular Sieves ◽  
Reaction Medium ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Optimal Reaction ◽  
Better Than

In order to significantly improve the biosynthesis of acyl-L-carnitines catalyzed by lipase, there must be an efficient and suitable reaction medium that is not only polar but also hydrophobic. [Bmim]PF6, which satisfies the above two requirements, was applied as the medium. The optimal reaction conditions were: for isovaleryl-L-carnitine, 0.22aW, 200mg molecular sieves, 60ºC, 4:1 of molar ratio (fatty acid:L-carnitine), 150rpm and 60h; for octanoyl-L-carnitine and palmitoyl-L-carnitine, 0.22aW, 250 mg molecular sieves, 5:1 of molar ratio (fatty acid:L-carnitine), 200rpm, 48h, 60ºC (octanoyl-L-carnitine) and 65ºC (palmitoyl-L-carnitine). Their overall yields could reach 59.14%, 90.79% and 98.03%, respectively. The yields of isovaleryl-L-carnitine, octanoyl-L-carnitine and palmitoyl-L-carnitine in [Bmim]PF6 were 16.21%, 73.67% and 44.22 % more than those in acetonitrile, respectively. [Bmim]PF6 as the medium was better than acetonitrile. It could not only enhance the yields of acyl-L-carnitines, but also protect the lipase activity.

scholarly journals Biodiesel Production from a Novel Nonedible Feedstock, Soursop (Annona muricata L.) Seed Oil

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2562 ◽  
Author(s):  
Chia-Hung Su ◽  
Hoang Nguyen ◽  
Uyen Pham ◽  
My Nguyen ◽  
Horng-Yi Juan
Keyword(s):  
Reaction Time ◽  
Seed Oil ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Annona Muricata ◽  
Reaction Conditions ◽  
Biodiesel Feedstock ◽  
Acid Catalyzed ◽  
American Society ◽  
Optimal Reaction

This study investigated the optimal reaction conditions for biodiesel production from soursop (Annona muricata) seeds. A high oil yield of 29.6% (w/w) could be obtained from soursop seeds. Oil extracted from soursop seeds was then converted into biodiesel through two-step transesterification process. A highest biodiesel yield of 97.02% was achieved under optimal acid-catalyzed esterification conditions (temperature: 65 °C, 1% H2SO4, reaction time: 90 min, and a methanol:oil molar ratio: 10:1) and optimal alkali-catalyzed transesterification conditions (temperature: 65 °C, reaction time: 30 min, 0.6% NaOH, and a methanol:oil molar ratio: 8:1). The properties of soursop biodiesel were determined and most were found to meet the European standard EN 14214 and American Society for Testing and Materials standard D6751. This study suggests that soursop seed oil is a promising biodiesel feedstock and that soursop biodiesel is a viable alternative to petrodiesel.

Catalytic Synthesis of Isoamyl Acetate by Ion Exchange Resin-Supported (NH4)6[MnMo9O32] • 8H2O with Waugh Structure

2013 ◽  
Vol 750-752 ◽  
pp. 1231-1234 ◽  
Author(s):  
Li Xia Wang ◽  
Shu Heng Liu ◽  
Hua Yuan ◽  
Lin Lin Guo
Keyword(s):  
Ion Exchange ◽  
Exchange Resin ◽  
Orthogonal Experiment ◽  
Catalytic Efficiency ◽  
Ion Exchange Resin ◽  
Isoamyl Acetate ◽  
Molar Ratio ◽  
Solid Catalyst ◽  
Reaction Conditions ◽  
Optimal Reaction

Ion exchange resin-supported (NH4)6[MnMo9O32]8H2O with Waugh structure is used to prepare supported solid catalyst. Performance of this catalyst is researched by means of synthesis of isoamyl acetate. Optimal reaction conditions determined by orthogonal experiment are as follows: acid-alcohol molar ratio is 2.5:1, reaction time is 120 min, catalyst dosage is 0.8 g, dosage of water-carrying agent is 2.5 ml, esterification yield reaches 95.1%. This catalyst is characterized by high catalytic efficiency, easy separation and recovery, absence of environmental pollution and being reusable, etc.

scholarly journals PREPARATION OF [AcMI] HSO4 AND USING AS CATALYST FOR ESTERIFICATION

2011 ◽  
Vol 14 (4) ◽  
pp. 61-73
Author(s):  
Thu Ngoc Ha Le ◽  
Thach Ngoc Le
Keyword(s):  
Ionic Liquid ◽  
Chloroacetic Acid ◽  
Molar Ratio ◽  
Hydrogen Sulfate ◽  
Reaction Conditions ◽  
Brønsted Acidic Ionic Liquid ◽  
Acidic Sites ◽  
Concentrated Sulfuric Acid ◽  
Zwitter Ion ◽  
Optimal Reaction

New Bronsted acidic ionic liquid, 1-carboxymethyl-3-methylimidazolium hydrogen sulfate [AcMI]HSO4, has two acidic sites -COOH and HSO4 -. It has been synthesized by three steps. First, 1-carboxymethyl-3-methylimidazolium chloride [AcMI]Cl was prepared by alkylation of 1- methylimidazole with chloroacetic acid (molar ratio is 1.5:1) under microwave irradiation in 6 min (84 % isolated yield). Then, zwitter ion 1-carboxylatmethyl-3-methylimidazolium was obtained by using Ag2O to remove ion chloride Cl- from [AcMI]Cl. At last, concentrated sulfuric acid (98 %) was added into zwitter ion to give 1-carboxymethyl-3-methylimidazolium hydrogen sulfate (yield 96 %). This ionic liquid used as a recyclabe catalyst for the esterification of isopropanol and chloroacetic acid. The optimal reaction conditions were obtained as follows: isopropanol: chloroacetic acid:[AcMI]HSO4 are 1.3:1:0.2, reaction time for 10 min at 60 oC under microvave irradiation. The yield of isopropyl chloroacetate was 86 %. This ionic liquid was removed from ester easily, recovered and recycled without loss of activity.

scholarly journals Identification and Antioxidant Abilities of Enzymatic-Transesterification (−)-Epigallocatechin-3-O-gallate Stearyl Derivatives in Non-Aqueous Systems

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1282
Author(s):  
Chengyu Jiang ◽  
Li Wang ◽  
Xin Huang ◽  
Song Zhu ◽  
Chaoyang Ma ◽  
...  
Keyword(s):  
Soybean Oil ◽  
Lipid Oxidation ◽  
Aqueous System ◽  
Molar Ratio ◽  
Antioxidant Ability ◽  
High Fat ◽  
Reaction Conditions ◽  
Enzymatic Transesterification ◽  
Optimal Reaction ◽  
Application Prospects

Vinyl stearate was added to enzymatic transesterification of (−)-Epigallocatechin-3-O-gallate (EGCG) to enhance its lipophilicity and antioxidant ability in a non-aqueous system. The lipase DF “Amano” 15 was used as the catalyst. The optimal reaction conditions were: acetonitrile as the solvent, the molar ratio of vinyl stearate: EGCG as 3:1, an enzyme amount of 4.0% (ratio of substrate mass), and a reaction temperature and time of 50 °C and 96 h, respectively, achieving 65.2% EGCG conversion. HPLC–MS and NMR were used to determine the structure of EGCG stearyl derivative (3″,5″-2-O-stearyl-EGCG). The lipophilicity of EGCG stearyl derivatives (3.49 ± 0.34) was higher (5.06 times) than that of the parent EGCG (0.69 ± 0.08). Furthermore, EGCG stearyl derivatives had excellent lipid oxidation compared with BHT, BHA, and parent EGCG. The POVs of soybean oil with EGCG stearyl derivatives (18.17 ± 0.92 mEq/kg) were significantly reduced (by 62.5%) at 21 d compared with those of EGCG (48.50 ± 1.23 mEq/kg). These results indicate that EGCG derivatives have broad antioxidant application prospects in lipophilic environments/high-fat food.

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.

scholarly journals SYNTHESIS OF ETHYL ETHER OF 4(4-HYDROXYPHENYL)- AND 4′-METHYL-4(4-HYDROXYPHENYL)CYCLOHEXANCARBONIC ACIDS AND THEIR AMINOMETHYLATED DERIVATIVES

2020 ◽  
Vol 63 (4) ◽  
pp. 22-27
Author(s):  
Mehriban V. Naghiyeva
Keyword(s):  
Reaction Time ◽  
Orthophosphoric Acid ◽  
Zeolite Y ◽  
Ethyl Esters ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Acid Yield ◽  
Aminomethyl Derivatives ◽  
Derivatives Of ◽  
Optimal Reaction

The article presents the results of cycloalkylation of phenol with ethyl cyclohexane- and 4-methylcyclohexenecarboxylic esters in the presence of a zeolite-Y catalyst impregnated with phosphoric acid. It has been established that to perform the cycloalkylation of phenol with ethyl cyclohexenecarboxylic acid in the presence of a zeolite-Y catalyst impregnated with orthophosphoric acid, the optimal conditions are: temperature 120 °С, reaction time 5 h, molar ratio of phenol to ether 1 : 1 mol/mol. And amount of catalyst is 10% for taken phenol. The yield of the target product was 74.7% of the theory for taken phenol, and selectivity - 93.8% for the target products. It was found that under optimal reaction conditions cycloalkylation (temperature 110 °C, reaction time 4 h, the ratio of phenol to ether 1 : 1, the amount of catalyst 7%) of phenol with ethyl 4-methylcyclohexenecarboxylic acid yield of ethyl 4 (4-hydroxyphenyl) -4'-methylcyclohexane-carboxylic) acid was 78.3% of the theory per phenol taken, and the selectivity was 95.7% for the desired product. The synthesis of aminomethyl derivatives of 4-hydroxyphenylcyclohexanecarboxylic acids in the presence of formalin and aniline was also carried out. As a result of aminomethylation, ethyl esters of 4 (4-hydroxy-3-phenylaminobenzyl) cyclohexane- and 4 (4-hydroxy-3-phenylaminobenzyl) -4'-methylcyclohexanecarboxylic acid were obtained. The yields of the target products were 67.3 and 71.7%, respectively, from the theory on taken ether. The structure and composition of the products were determined using IR and 1H NMR spectroscopy. And the purity of the products obtained was studied by chromatographic analysis. Ethyl esters of 4 (4-hydroxy-3-phenylaminobenzyl) cyclohexane- and 4 (4-hydroxy-3-phenylaminobenzyl) -4'-methylcyclohexanecarboxylic acid can be used as an antioxidant to diesel fuel and turbine oil T-46.

Synthesis of Benzaldehyde 1, 2-Propanediol Acetal by Using Ionic Liquid [Hmim]HSO4 as Catalyst

2012 ◽  
Vol 550-553 ◽  
pp. 400-403 ◽  
Author(s):  
Xue Nan Sun ◽  
Li Cui ◽  
Tong Kuan Xu ◽  
Da Zhi Wang
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Raw Materials ◽  
Product Yield ◽  
Experimental Results ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Good Catalyst ◽  
Optimal Reaction

Benzaldehyde 1, 2-propanediol acetal was synthesized from benzaldehyde and 1, 2-propanediol in the presence of ionic liquid [HMIM]HSO4. The effect of the amount of catalyst, reaction time, reaction temperature, and the molar ratio of raw materials agent on the product yield was investigated respectively. Experimental results demonstrate that ionic liquid [HMIM]HSO4is a good catalyst for preparation of benzaldehyde 1, 2-propanediol acetal. Results showed the optimal reaction conditions are as follows: the mole ratio of benzaldehyde to 1, 2-propanediol is 1：1.3, the amount of catalyst is 3.0g, the reaction temperature is 343K, and the reaction time is 4h. The achieved yield of acetal is 78. 7%.

Enzymatic preparation of structured TAG containing conjugated linoleic acid (CLA) at solvent-free

2020 ◽  
Vol 16 (8) ◽  
Author(s):  
Dianyu Yu ◽  
Jun Chen ◽  
Jie Cheng ◽  
Yan Chen ◽  
Lianzhou Jiang ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Rice Bran ◽  
Rice Bran Oil ◽  
Molar Ratio ◽  
Light Phase ◽  
Reaction Conditions ◽  
Lipozyme Rm Im ◽  
Structured Tag ◽  
Optimal Reaction

AbstractRice bran oil extracted by the water-enzymatic method was placed at a temperature of −5 °C for 8 h. Light-phase rice bran oil with an iodine value of 112.13 ± 0.21 g I2/100 g oil was separated by cryogenic freezing centrifugation. Lipozyme RM IM transesterified light-phase rice bran oil and conjugated linoleic acid (CLA) under supercritical system CO2 (SC-CO2). The optimal reaction conditions for transesterification of CLA and rice bran oil in SC-CO2 were determined as follows: the Lipozyme RM IM dosage was 9%, and the RBO/CLA molar ratio was 1:3, the reaction temperature was 55 °C, stirring speed was 300 rpm, and transesterification time was 20 h, the CLA conversion rate can reach 42.1%.

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