- Palladium-Catalyzed Butoxycarbonylation of Polybromo(hetero)arenes: A Practical Method for the Preparation of (Hetero)arenepolycarboxylates and -carboxylic Acids
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The palladium-catalyzed alkoxycarbonylation of polybromo (hetero)arenes was investigated systematically. The results show that cheap and readily available in situ Pd(OAc) 2/ rac -BINAP catalyst can catalyze the butoxycarbonylation of various polybromo(hetero)arenes efficiently, and gave (hetero)arenepolycarboxylates with moderate to high yield (59-94%). Using this method, two new compounds, 4,4'-bis(butoxycarbonyl)-1,1'-bi-2-naphthol and dibutyl [2,2'-bipyrimidine]-5,5'-dicarboxylate, are reported for the first time. In addition, the gram-scale preparation of carboxylate and carboxylic acids was successful performed by butoxycarbonylation followed by hydrolysis. This shows the wide scope of substrates and practical applications of the Pd(OAc) 2/ rac -BINAP catalytic system. Moreover, these carboxylic acids and carboxylates can be used as ligands or structural units to construct MOFs, metal complexes, and COFs etc.
- Wu, Weilong,Jing, Yongkang,Zhang, Deyi,Yan, Xianghe,Liang, Rong,Lu, Zhiqiang,Ji, Baoming
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p. 403 - 410
(2021/10/12)
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- Method for catalyzing esterification reaction of low-carbon alcohol by using ionic liquid
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The invention discloses a method for catalyzing low-carbon alcohol esterification reaction by ionic liquid, which comprises the following steps: mixing dianhydride or diacid, fatty alcohol and ionic liquid, heating to 100-160 DEG C by microwave, and reacting for 0.5-2 hours to obtain diester; wherein the ionic liquid is [Ps2TMEDA] [HSO4] 2 and/or [Ps2BPy] [HSO4] 2, the molar ratio of the ionic liquid to the dianhydride or diacid is 0.005-0.04, and the molar ratio of the dianhydride or diacid to the fatty alcohol is 1-5. The method is simple in process, mild in condition, convenient to operate, environment-friendly, high in double esterification degree, high in ionic liquid activity and easy to separate.
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Paragraph 0022; 0027-0028; 0032
(2021/07/24)
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- Preparation method for dibutyl phthalate
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The invention discloses a preparation method for dibutyl phthalate. The preparation method at least comprises the following steps: a, placing phthalic anhydride and n-butyl alcohol into a container according to a mass ratio of 1: 2-1: 3, and adding a sulfate ionic liquid into the container as a catalyst under stirring; b, carrying out cooling and refluxing for 3-5 hours at a temperature of 120-140DEG C; c, after refluxing is completed, carrying out reduced pressure distillation at 65-75 DEG C until residual n-butyl alcohol and water are discharged, and carrying out reduced pressure distillation at 215-225 DEG C so as to distill out a transparent faint-yellow oily liquid with aromatic smell, namely the dibutyl phthalate, wherein the sulfate ionic liquid is any one selected from the group consisting of [MIM-PS][H2SO4], [Py-PS][H2SO4], [TEA-PS][H2SO4], [HNMP][H2SO4] and [DMF][H2SO4]; and the mass ratio of the phthalic anhydride to the sulfate ionic liquid is 1: 0.15-1: 0.25. The preparation method provided by the invention has the following beneficial effects: the sulfate ionic liquid is used as the catalyst, so the catalytic yield of the process is finally high; the threat to the environment is small; meanwhile, the sulfate ionic liquid can be repeatedly used, so good market prospect is achieved.
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Paragraph 0020-0064
(2020/07/12)
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- Green and clean production process for preparing dibutyl phthalate
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The invention provides a green and clean production process for preparing dibutyl phthalate. The process comprises the following steps: carrying out an esterification reaction on phthalic anhydride and n-butyl alcohol, both used as raw materials, under the action of a catalyst, namely sulfuric acid; adding an excessive anion exchange material into a reaction solution after the esterification reaction is finished; carrying out stirring to remove the catalyst sulfuric acid; carrying out solid-liquid separation after the stirring is finished; and carrying out subsequent refining process on a filtrate. According to the process, an anion exchange material is used as a treating agent to remove the catalyst sulfuric acid, and sodium sulfate mingled with a large amount of dangerous solid waste andneutralized wastewater cannot be generated; the anion exchange material is regenerated by adopting an aqueous sodium hydroxide solution, and a clean sodium sulfate solution with a mass concentrationnot greater than 4% is obtained after regeneration; and the clean sodium sulfate solution can be used for preparation of sodium sulfate or be directly discharged, and can be regenerated into sulfuricacid and the sodium hydroxide solution for cycle use by using bipolar membrane electrodialysis.
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Paragraph 0019-0030
(2020/02/29)
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- Synthesis and characterization of butylamine-functionalized Cr(III)–MOF–SO3H: Synergistic effect of the hydrophobic moiety on Cr(III)–MOF–SO3H in esterification reactions
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Mesoporous solid acid catalysts with partially hydrophobic moieties, [Cr3O(BDC–SO3H)3?x(BDC–SO3NH3Bu)x]n, were prepared from [Cr3O(BDC–SO3H)3]n (MIL-101(Cr)–SO3H) and BuNH2 for the first time and then characterized by the Brunauer–Emmet–Teller (BET) technique, powder X-ray diffraction, field emission electron microscopy, Fourier transform infrared spectroscopy, and thermal and elemental analyses. The nitrogen adsorption–desorption study showed that the specific surface area and total pore volume of MIL-101(Cr)–SO3H decreased after the reaction with butylamine and formation of [Cr3O(BDC–SO3H)3?x(BDC–SO3NH3Bu)x]n. The prepared materials were used as catalysts to investigate the impact of hydrophobic moieties in esterification yields of phthalic anhydride with several alcohols as a probe reaction. The presence of butylamine as a hydrophobic group on MIL-101(Cr)–SO3H increases the esterification yield significantly for hydrophilic alcohols under solvent-free conditions. Moreover, results showed that [Cr3O(BDC–SO3H)3?x(BDC–SO3NH3Bu)x]n can be recovered and reused for several consecutive reactions without significant loss in catalyst activity.
- Alavijeh, Masoumeh Karimi,Amini, Mostafa M.
-
-
- Visible-Light-Driven Self-Coupling of Methylarenes Catalyzed by Ni2P?Cd0.5Zn0.5S Nanoparticles
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The Ni2P?Cd0.5Zn0.5S nanoparticles photocatalyzed self-coupling of p-xylene was reported here, and the corresponding coupling product 1,2-di-p-tolylethane was obtained. The reaction could be extended to toluene derivatives with electron-donating and electron-withdrawing substituents. Ni2P?Cd0.5Zn0.5S nanoparticles had already been characterized by XRD, ICP-AES, SEM, TEM, UV/Vis, FL, XPS. The Mott–Schottky curves of Ni2P?Cd0.5Zn0.5S were made through electrochemical methods. An active carbon free-radical was captured through ESR measurement under irradiation. The research demonstrated this photocatalytic system feasible for the self-coupling reaction of toluene derivatives.
- Yang, Dan-Dan,Hu, Jia-Jun,Zhang, Hong,Lv, Xiao-Jun,Chen, Yong,Fu, Wen-Fu
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p. 1384 - 1392
(2020/01/08)
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- Diacidic ionic liquid supported on magnetic-silica nanocomposite: a novel, stable, and reusable catalyst for selective diester production
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Abstract: Supported diacidic ionic liquid on magnetic silica nanoparticles (SDAIL@magnetic nanoSiO2) was successfully prepared through a multi-step approach. 2,2- bis ((3- methylimidazolidin-1-yl) methyl) propane- 1,3- diol bromide salt was immobilized onto the surface of magnetic silica nanoparticles via covalent bonding to prepare a novel powerful acidic catalyst. The synthesized catalyst was characterized by FT-IR, SEM, TGA, VSM, N2 adsorption–desorption measurements and acid-base titration. The catalytic activity of the prepared SDAIL@magnetic nanoSiO2 was investigated for the selective diesterification of alcohols by phthalic anhydride to afford corresponding dialkyl plasticizers under solvent-free conditions. The nature of two acidic counter anions as well as the presence of Lewis acidic species (Fe3O4) on the magnetic nanosilica and high surface area of the nanosilica influenced the behavior of the catalyst. Surperisingly, the high acidic character of the catalyst facilitates the reaction with a short reaction time. Furthermore, TG analysis strongly demonstrates that major content of IL is still stable on the support up to 290?°C, so catalyst has a good thermal stability. Under the optimized conditions, the conversion of phthalic anhydride was 100% and diester plasticizers were obtained with excellent yields (80–100%). The SDAIL@magnetic nanoSiO2 catalyst showed a good reusability and could be easily separated from the reaction mixture using an external magnet thanks to its superparamagnetic behavior and reused for several runs without significant activity loss. An important advantage of the SDAIL@magnetic nanoSiO2 was its high-hydrophilicity resulted in excellent selectivity towards the formation of only diesters which are commonly used plasticizers in different industries. Graphical abstract [Figure not available: see fulltext.].
- Fareghi-Alamdari, Reza,Nadiri Niri, Mehri,Hazarkhani, Hassan,Zekri, Negar
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p. 2615 - 2629
(2018/09/13)
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- Method for synthesizing phthalate by using catalytic oxidation product of o-xylene or naphthalene
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The invention provides a method for synthesizing phthalate by using a catalytic oxidation product of o-xylene or naphthalene. The method is characterized by comprising the following steps: preparationof phthalic anhydride; and synthesis of phthalate. The synthesis of phthalate comprises material addition, dropwise addition of n-butanol, and a negative-pressure reaction. The method for synthesizing phthalate in the invention has low reaction temperature which is 105 DEG C or below; the method is low in the usage amount of alcohol, and the molar usage amount of alcohol is 2.05 times of the usage amount of phthalic anhydride; the method is high in reaction yield, and the reaction yield is more than 99.4%; and after 10 times of indiscriminate application, the yield can be maintained at 99.0%.
- -
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Paragraph 0030; 0035
(2019/01/08)
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- Micro-flow nanocatalysis: synergic effect of TfOH@SPIONs and micro-flow technology as an efficient and robust catalytic system for the synthesis of plasticizers
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The combination of continuous flow technology with immobilizing of only 0.13?mol% of triflic acid (TfOH) on silica-encapsulated superparamagnetic iron oxide nanoparticles (SPIONs) under solvent-free conditions successfully provided a powerful, efficient, and eco-friendly route for the synthesis of plasticizers. The turnover frequency value in micro-flow conditions varied in the range of 948.7 to 7384.6 h?1 compared to 403.8 to 3099 h?1 for in-flask. This technique works efficiently, encouraging future applications of micro-flow nano-catalysis in green chemistry.
- Tashi, Maryam,Shafiee, Behnaz,Sakamaki, Yoshie,Hu, Ji-Yun,Heidrick, Zachary,Khosropour, Ahmad R.,Beyzavi, M. Hassan
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p. 37835 - 37840
(2018/11/26)
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- Production of Plant Phthalate and its Hydrogenated Derivative from Bio-Based Platform Chemicals
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Direct transformation of bio-based platform chemicals into aromatic dicarboxylic acids and their derivatives, which are widely used for the manufacture of polymers, is of significant importance for the sustainable development of the plastics industry. However, limited successful chemical processes have been reported. This study concerns a sustainable route for the production of phthalate and its hydrogenated derivative from bio-based malic acid and erythritol. The key Diels–Alder reaction is applied to build a substituted cyclohexene structure. The dehydration reaction of malic acid affords fumaric acid with 96.6 % yield, which could be used as the dienophile, and 1,3-butadiene generated in situ through erythritol deoxydehydration serves as the diene. Starting from erythritol and dibutyl fumarate, a 74.3 % yield of dibutyl trans-4-cyclohexene-1,2-dicarboxylate is obtained. The palladium-catalyzed dehydrogenation of the cycloadduct gives a 77.8 % yield of dibutyl phthalate. Dibutyl trans-cyclohexane-1,2-dicarboxylate could be formed in nearly 100 % yield under mild conditions by hydrogenation of the cycloadduct. Furthermore, fumaric acid and fumarate, with trans configurations, were found to be better dienophiles for this Diels–Alder reaction than maleic acid and maleate, with cis configuration, based on the experimental and computational results. This new route will pave the way for the production of environmental friendly plastic materials from plants.
- Lu, Rui,Lu, Fang,Si, Xiaoqin,Jiang, Huifang,Huang, Qianqian,Yu, Weiqiang,Kong, Xiangtao,Xu, Jie
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p. 1621 - 1627
(2018/06/15)
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- A novel hydrogen-bonded silica-supported acidic ionic liquid: An efficient, recyclable and selective heterogeneous catalyst for the synthesis of diesters
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Abstract: In this study, two novel acidic ionic liquids, including a hydroxyl functionalized diacidic ionic liquid [HFDAIL] and a sulfonated diacidic ionic liquid [SFDAIL], were prepared and immobilized on the surface of silica nanoparticles (SNPs) via hydrogen bonding. The materials were characterized by FT-IR, NMR, SEM, nitrogen physisorption measurement, TGA and acid-base titration. The catalytic activity of the prepared catalysts was investigated in the synthesis of phthalate, maleate and succinate diesters under solvent-free conditions. It was found that nanosilica@[HFDAIL] with higher availability of acidic sites and higher hydrophilicity was more efficient compared to the nanosilica@[SFDAIL]. Notably, nanosilica@[HFDAIL] catalyst has also demonstrated excellent selectivity for the diester product while the monoester product was predominant in the case of nanosilica@[SFDAIL] even after prolonged reaction time or higher catalyst loading. In addition, the nanosilica@[HFDAIL] catalyst could be separated by simple filtration and reused several times without any significant loss of catalytic performance, but a remarkable decrease in activity was observed for nanosilica@[SFDAIL] in the next runs. GRAPHICAL ABSTRACT?: SYNOPSIS Two novel acidic ionic liquids, including a hydroxyl functionalized diacidic ionic liquid [HFDAIL] and a sulfonated diacidic ionic liquid [SFDAIL], were prepared and immobilized on the surface of silica nanoparticles via hydrogen bonding. The catalytic activity of the catalysts was investigated in the synthesis of diesters under solvent-free conditions.
- Fareghi-Alamdari, Reza,Niri, Mehri Nadiri,Hazarkhani, Hassan
-
-
- Synthesis and characterization of a new hydroxyl functionalized diacidic ionic liquid as catalyst for the preparation of diester plasticizers
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Two new functionalized diacidic ionic liquids (FDAILs) including hydroxyl functionalized diacidic ionic liquid (HFDAIL) and sulfonated diacidic ionic liquid (SFDAIL) were synthesized and characterized by 1HNMR, 13CNMR and FT-IR. The catalytic activities of these FDAILs were examined in esterification reaction of anhydrides with some alcohols to give corresponding dialkyl plasticizers under solvent-free conditions. The results indicate that HFDAIL, as hydroxyl-bearing catalyst, show better catalytic performance. Under the optimum conditions, using HFDAIL, the conversion of phthalic anhydride was high and diester plasticizers were obtained with good to excellent yields in the presence of only 10?mol% of ionic liquid. All the produced diesters could be easily recovered due to their immiscibility with the ionic liquid. Recycling experiments suggests that these ionic liquids can be reused several times without remarkable loss in their catalytic activity.
- Fareghi-Alamdari, Reza,Nadiri Niri, Mehri,Hazarkhani, Hassan
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p. 153 - 160
(2016/12/30)
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- A synthetic phthalic acid ester compound of the method (by machine translation)
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The present invention provides a phthalic acid ester compound synthesis method. In order to weak acid as main catalyst, supplemented by other cocatalyst to form composite catalyst synthesis phthalic acid ester compound, specific steps are as follows: the phthalic anhydride, alcohol and composite catalyst in the reactor, phthalic anhydride with an alcohol in a molar ratio of 1: 2.1 - 5.0, the adding amount of the composite catalyst for phthalic anhydride of the weight of the 0.2% -10%. To ensure that the reactor sealed, heated to boiling, reaction 0.5 - 2 hours, distillation, the product is obtained. The method of the invention can achieve the catalytic effect of the concentrated sulfuric acid, but also can overcome the disadvantage, and the use of the catalyst can be prepared by the conventional method separation and recovery, greatly simplifies the separation procedure, convenient for continuous production. (by machine translation)
- -
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Paragraph 0023-0050
(2017/04/19)
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- Ultrasound-assisted removal of Acid Red 17 using nanosized Fe3O4-loaded coffee waste hydrochar
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The Fe3O4-loaded coffee waste hydrochar (Fe3O4-CHC) was synthesized using a simple precipitation method. The as-prepared adsorbent was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and Fourier transform infrared spectroscopy (FT-IR). The EDX analysis indicated the presence of Fe in the structure of Fe3O4-CHC. The specific surface area of hydrochar increased from 17.2 to 34.7 m2/g after loading of Fe3O4 nanoparticles onto it. The prepared Fe3O4-CHC was used for removal of Acid Red 17 (AR17) through ultrasound-assisted process. The decolorization efficiency decreased from 100 to 74% with the increase in initial dye concentration and from 100 to 91 and 85% in the presence of NaCl and Na2SO4, respectively. The synthesized Fe3O4-CHC exhibited good stability in the repeated adsorption-desorption cycles. The high correlation coefficient (R2 = 0.997) obtained from Langmuir model indicated that physical and monolayer adsorption of dye molecules occurred on the Fe3O4-CHC surface. Furthermore, the by-products generated through the degradation of AR17 was identified by gas chromatography–mass spectrometry analysis.
- Khataee, Alireza,Kayan, Berkant,Kalderis, Dimitrios,Karimi, Atefeh,Akay, Sema,Konsolakis, Michalis
-
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- Functionalized dicationic ionic liquids: Green and efficient alternatives for catalysts in phthalate plasticizers preparation
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Two highly acidic, imidazolium-based, functionalized dicationic ionic liquids (FDCILs) were synthesized and characterized by FTIR, 1H NMR and13C NMR. The synthesized FDCILs were used as efficient and green catalysts in the synthesis of phthalate plasticizers through esterification of phthalic anhydride (PhA) with ethanol, n-propanol and n-butanol. Among these two FDCILs, (dimethyl-4-sulfobutyl-ammonium) 1,2-ethan-1-methyl-imidazolium-sulfonic acid hydrogen sulfate performed better. The catalytic activity of FDCIL is related to the density of acidic groups on it and the length of the carbon chain in the cationic part. The influences of the reaction temperature, catalyst dosage, and molar ratio of phthalic anhydride to alcohol on the esterification reaction were investigated. The reusability of the catalyst in these reactions was studied too. The diester phthalates were obtained up to 98.8% yield. The products can be separated easily by decantation from the reaction mixture. [Figure not available: see fulltext.]
- Zekri, Negar,Fareghi-Alamdari, Reza,Khodarahmi, Zahra
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p. 1277 - 1284
(2016/08/16)
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- A liquid phase oxidation of O-xylene with esterification coupling preparation of phthalic acid diester method
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The invention relates to a method for preparation of diester phthalate by o-xylene liquid-phase oxidation and esterification coupling. In the presence of a catalyst, air or oxygen is used as an oxygen source for preparation of the diester phthalate by o-xylene liquid-phase oxidation and esterification coupling. The method has the advantages of mild reaction conditions, safe operation, low raw material and energy consumption, high conversion rate and high selectivity and the like.
- -
-
Paragraph 0020-0023; 0026
(2017/02/24)
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- Novel integrated carbon particle based three dimensional anodes for the electrochemical degradation of reactive dyes
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Three-dimensional carbon bed electrochemical reactors have been recently applied for the degradation of several organic pollutants. However, the carbon particles in such reactors slowly undergo attrition. We fabricated a novel flow-through three-dimensional anode using granular activated carbon (GAC) particles and polyvinylidene fluoride (PVDF) binder that potentially avoids such attrition. Optimization of the composition of GAC and PVDF with respect to mechanical integrity and electrical conductivity is reported. The anodes were tested in the electro oxidation of the reactive dyes: Reactive Orange-16 (RO-16), Reactive Red-2 (RR-2), and Reactive Blue-4 (RB-4). A tentative mechanism of dye degradation was proposed based on the observed role of the supporting electrolyte and the cyclic voltammetric, UV-vis, FT-IR and GC-MS data. The decolorization efficiencies were 75 ± 3, 81 ± 5 and 88 ± 4% for RB-4, RO-16 and RR-2, respectively. The integrated 3-D anodes are advantageous because of the absence of carbon attrition, which is otherwise found when a bed of GAC is used in the electrochemical reactors.
- Misra, Rohit,Neti, Nageswara Nao,Dionysiou, Dionysios D.,Tandekar, Mahendra,Kanade, Gajanan S.
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p. 10799 - 10808
(2015/02/05)
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- Large disk electrodes of Ti/TiO2-nanotubes/PbO2 for environmental applications
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Large disk electrodes of Ti/TiO2-nanotubes/PbO2 (65 cm2 of geometrical area) were successfully synthesized by anodization and electrodeposition procedures. Characterization of anodes was performed by SEM, EDS, AFM and electrochemical measurements, aiming towards environmental applications. PbO2, an electrocatalytic material, promotes the production of strong oxidising species (hydroxyl radicals) that can be used for decontamination. Electrochemical treatment of synthetic dye effluent (2 L) containing 250 mg L-1 of Acid Blue 113 dye (AB 113) was performed using a disk Ti/TiO2-nanotubes/PbO2 anode and an electrochemical flow cell. More than 85% of organic matter was removed by applying current densities of 20, 40 and 60 mA cm-2. Moreover, colour decay achieved values of 60%, 90% and 100%, depending on the applied current density. Alternatively, this study allows us to understand how nanomaterials have prevented the corrosion phenomena on the anode surface (Pb2+ pollution) due to the homogeneous migration of PbO2 within the TiO2 nanotubes previously formed on the Ti support.
- Chianca De Moura, Dayanne,Cerro-López, Mónica,Quiroz, Marco Antonio,Ribeiro Da Silva, Djalma,Martínez-Huitle, Carlos Alberto
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p. 31454 - 31459
(2015/04/22)
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- One-pot esterification and amide formation via acid-catalyzed dehydration and ritter reactions
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Esterification of carboxylic acid is achieved using acetonitrile as a water trap. Water liberated during esterification is consumed in cyanide hydrolysis, thereby driving the esterification to completion. Substrates having carboxylic acid and nitrile groups undergo intramolecular dehydration and rehydration to amido esters in the absence of acetonitrile. Cyano acids also undergo esterification and Ritter reaction in one pot when excess alcohol is used. For the first time, we have observed an interesting Ritter reaction of primary alcohols, leading to ester amide product in one pot. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Dawar, Pankaj,Raju, M. Bagavan,Ramakrishna, Ramesha Andagar
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supporting information
p. 836 - 846
(2014/03/21)
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- Sulfonated graphene as highly efficient and reusable acid carbocatalyst for the synthesis of ester plasticizers
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Plasticizers are well known for their effectiveness in producing flexible plastics. The automotive, plastic and pharmaceutical industries, essential to a healthy economy, rely heavily on plasticizers to produce everything from construction materials to medical devices, cosmetics, children toys, food wraps, adhesives, paints, and 'wonder drugs'. Although H2SO4 is commonly used as commodity catalyst for plasticizer synthesis it is energy-inefficient, non-recyclable, and requires tedious separation from the homogeneous reaction mixture resulting in abundant non-recyclable acid waste. In this study, for the first time, we report an efficient synthesis of ester plasticizers (>90% yields) using sulfonated graphene (GSO3H) as an energy-efficient, water tolerant, reusable and highly active solid acid carbocatalyst. The hydrothermal sulfonation of reduced graphene oxide with fuming H2SO4 at 120°C for 3 days afforded GSO3H with remarkable acid activity as demonstrated by 31P magic-angle spinning (MAS) NMR spectroscopy. The superior catalytic performance of GSO3H over traditional homogeneous acids, Amberlyst-15, and acidic ionic liquids has been attributed to the presence of highly acidic and stable sulfonic acid groups within the two dimensional graphene domain, which synergistically work for high mass transfer in the reaction. Furthermore, the preliminary experimental results indicate that GSO3H is quite effective as a catalyst in the esterification of oleic and salicylic acid and thus may pave the way for its broad industrial applications in the near future.
- Garg, Bhaskar,Bisht, Tanuja,Ling, Yong-Chien
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p. 57297 - 57307
(2015/02/02)
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- Synthesis of carboxylic acid esters in the presence of micro- and mesoporous aluminosilicates
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The catalytic properties of zeolites HY, HBeta, and HZSM-12 and of mesoporous amorphous aluminosilicate in liquid-phase esterification of aliphatic (monobasic C1-C18, dibasic C6, C10) and aromatic (benzoic, trimellitic, phthalic) carboxylic acids with butanol were studied. Zeolite HBeta appeared to be the most active catalyst. Procedures were developed for preparing esters in the presence of zeolitic catalyst HBeta, ensuring 100% selectivity of ester formation at 90-98% conversion of the acid.
- Grigor'Eva,Suleimanova,Agliullin,Kutepov
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p. 773 - 779
(2015/01/30)
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- Biotransformation of Licochalcone A by transgenic crown galls of Panax quinquefolium
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Licochalcone A, as main constituent of Chinese Gancao (Glycyrrhiza inflate Bat), is responsible for thechemopreventive effect of the herbal. In order to get the bioactive modified molecules of Licochalcone A,it was biotransformed using transgenic crown galls of Panax quinquefolium to afford 9 products includinga new alkaloid together with 8 known compounds. Their structures were elucidated by physicochemicaland spectral methods as: methyl(12S)-1-[(5-formylfuran-2-yl)methyl]-5-oxopyrrolidine-2-carboxylate(1), methyl(12S)-1-[2-(furan-2-yl)-2-oxoethyl]-5-oxopyrrolidine-2-carboxylate (2), 5-hydroxymethyl-2-furfural (3), (S)-methylpyroglutamate (4), 4-hydroxy-2-methoxy-5-(2-methylbut-3-en-2-yl) benz-aldehyde (5), 4-hydroxybenzoicacid (6), dibutyl phthalate (7), 3β,6α,12β,25-tetrahydroxy-(20S,24R)-epoxy-dammarane (8), β-sitosterol (9).Among them, compounds 5 and 6 were transformed from Licochalcone A, while 14 and 8 were derivedfrom the culture medium stimulated by the substrate. Furthermore, their cancer chemopreventive effectwere tested by the assay of NQO1 (NAD(P)H: quinine oxidoreductase 1) inducing activities in Hepa 1c1ccells.
- Li, Jiayuan,Li, Ning,Huang, Bing,Zhao, Weihong,Wang, Wenli,Si, Yingying,Yan, Chunyan
-
-
- Facile microwave-assisted synthesis of monodispersed ball-like Ag@AgBr photocatalyst with high activity and durability
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We reported a rapid one-step microwave-assisted approach to synthesize a plasmonic photocatalyst of ball-like AgBr nanoparticles (ca. 290 nm in average diameter) with a small amount of metal Ag anchored on the surface. The obtained Ag@AgBr nanocomposites were characterized by means of X-ray diffraction, scanning electron microscopy, Transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and UV-visible diffuse reflectance spectroscopy. The shape, size, and compositions of the Ag@AgBr photocatalysts could be controlled by tuning the microwave irradiation time and the concentrations of polyvinylpyrrolidone (PVP) in the reaction solution. The as-prepared Ag@AgBr plasmonic photocatalysts show excellent visible-light photocatalytic performance and good reusability for decomposing organic pollutant of Rhodamine B (RhB) due to the surface plasmon resonance (SPR) effect of Ag nanoparticles. Meanwhile, the possible degradation pathways of RhB and a mechanism of the plasmonic photocatalytic process were also proposed.
- Xu, Xiang,Shen, Xiaoping,Zhou, Hu,Qiu, Dezhou,Zhu, Guoxing,Chen, Kangmin
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p. 183 - 192
(2013/05/21)
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- Synthesis of monoesters and diesters using eco-friendly solid acid catalysts - Cerium(IV) and thorium(IV) phosphates
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In the present endeavour, amorphous cerium phosphate (CP) and thorium phosphate (TP) have been synthesized by sol-gel method and also under microwave irradiation to yield CPM and TPM. CP, TP, CPM and TPM have been characterized for elemental analysis (ICP-AES), spectral analysis (FTIR), thermal analysis (TGA), X-ray diffraction studies, SEM, EDX, surface area (BET) and surface acidity (NH3-TPD). The potential use of these materials as solid acid catalysts has been explored by studying esterification as a model reaction. Monoesters such as ethyl acetate (EA), propyl acetate (PA), butyl acetate (BA), benzyl acetate (BzAc) and diesters such as diethyl malonate (DEM), diethyl succinate (DES), dibutyl phthalate (DBP), dioctyl phthalate (DOP) have been synthesized. Esterification conditions have been optimized by varying several parameters such as reaction time, catalyst amount and mole ratio of reagents. The catalytic activity has been compared and correlated with reference to surface acidity of the catalysts. It is found that catalytic activity of CPM > CP > TP M > TP. The regenerated catalysts could be reused upto two catalytic runs without significant loss in % yields of esters formed. The highlighting feature of the present work is the catalysts CPM and TPM that are synthesized in a much shorter reaction time with higher surface acidity giving good % yield of esters.
- Parangi, Tarun,Wani, Bina,Chudasama, Uma
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p. 430 - 438
(2013/09/23)
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- Efficient synthesis of symmetrical phthalate and maleate diesters using phosphinite ionic liquids
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Symmetrical dialkyl phthalates and maleates were synthesized using phosphinite ionic liquid as a catalyst and reaction medium. The results indicated that phosphinite ionic liquid shows better catalytic and reusable performance without using any acid or base catalyst. Under the optimum conditions, using 1-methyl-3-(4-phosphinitebutyl) imidazolium chloride as catalyst, the conversion of phthalic and maleic anhydrides to the corresponding diesters of primary and secondary alcohols was occurred in 72-85% yields. The diesters of tertiary alcohols and phenols could not be prepared by this method. A kind of widely used plasticizer, dioctyl phthalate, was prepared in good yield under these conditions. The ionic liquid could be reused three times after easy separation from the products without any disposal. Iranian Chemical Society 2012.
- Valizadeh,Khalili
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p. 529 - 534
(2013/02/22)
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- NOVEL FORMULATION OF DEHYDRATED LIPID VESICLES FOR CONTROLLED RELEASE OF ACTIVE PHARMACEUTICAL INGREDIENT VIA INHALATION
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A new formulation of dehydrated lipid vesicles employs a vesicle preserver and permits the control of release and delivery of active pharmaceutical ingredients into the respiratory system for treatment in particular of asthma. The typical formulation provides controlled release of the active pharmaceutical ingredient from 0% to 100% from 0 to 72 hours after inhalation, changes the systemic administration to topical administration, allows prolonged therapeutic period for one administration, increased stability, with reduced dose, reduced systemic side effects, reduced toxicity.
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- Use of zirconium(IV) phosphate as a solid acid catalyst in some esterification reactions
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Amorphous and crystalline phases of zirconium(IV) phosphate of the class of tetravalent metal acid (TMA) salts have been synthesized by sol-gel method. The materials have been characterized for elemental analysis (ICP-AES), thermal analysis (TGA), X-ray analysis, BET surface area, surface acidity (NH 3-TPD) and FTIR spectroscopy. Chemical resistivity of the materials has been accessed in acids, bases and organic solvent media. The exchangeable protons present in the structural hydroxyl groups indicate good potential for TMA salts to be investigated as solid acids. Esterification reaction has been selected as a model reaction to study the application of ZrP (amorphous and crystalline phases) as a solid acid. The catalytic activity explored by synthesizing monoesters and diesters reveals the promising use of ZrP as an ecofriendly solid acid catalyst.
- Patel,Joshi,Chudasama
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p. 348 - 352
(2008/09/19)
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- DEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBONS TO RENDER THEM AVAILABLE FOR BIODEGRADATION
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A method for the degradation of polycyclic aromatic compounds is disclosed that involves dissolving ozone in a bipolar solvent comprising a non-polar solvent in which is of sufficiently non-polar character to solubilized the polycyclic aromatic compounds, and a polar-water-compatible solvent which is fully miscible with the non-polar solvent to form a single phase with the non-polar solvent. The bipolar solvent with dissolved ozone is contacted with the polycyclic aromatic compounds to solubilize the polycyclic aromatic compounds and react the dissolved polycyclic aromatic compounds with the ozone to degrade the dissolved polycyclic aromatic compounds to oxygenated intermediates. The bipolar solvent is then mixed with sufficient water to form separate non-polar and polar phases, the non-polar phase comprising the non-polar solvent and the polar phase comprising the non-polar solvent and the oxygenated intermediates. The polar phase is then diluted and incubated with bacteria to biodegrade the oxygenated intermediates.
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Page/Page column 5-8; 15-16
(2008/12/07)
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- Scope and mechanistic insights into the use of tetradecyl(trihexyl) phosphonium bistriflimide: A remarkably selective ionic liquid solvent for substitution reactions
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A survey of substitution reactions conducted in a phosphonium bistriflimide ionic liquid is presented. The results demonstrate high selectivity favoring substitution over typically competitive elimination and solvolytic processes even when challenging secondary and tertiary electrophiles are employed. The first reports of Kornblum substitution reactions in an ionic liquid are described that proceed with very high chemoselectivity in favor of nitro over nitroso products and elimi nation side products. The structure-reactivity study indicates that these reactions proceed through a narrow spectrum of pathways ranging from straight SN2 to a preassociation pathway along a saddle point that approaches the SN1 limit. The barrier to the formation of dissociated carbocations is attributed to the structural features of this ionic liquid that favor intervention of the associated nucleophile over dissociation, also preventing cross over to E1 processes. The lack of any basic entity in the phosphonium bistriflimide ionic liquid appears to prevent any potential base-mediated elimination reactions, which makes this a highly selective medium for use in general substitution reactions.
- McNulty, James,Nair, Jerald J.,Cheekoori, Sreedhar,Larichev, Vladimir,Capretta, Alfredo,Robertson
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p. 9314 - 9322
(2007/10/03)
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- A mild esterification process in phosphonium salt ionic liquid
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A general, high yielding procedure is described for the esterification of carboxylic acids through carboxylate alkylation in phosphonium salt ionic liquid.
- McNulty, James,Cheekoori, Sreedhar,Nair, Jerald J.,Larichev, Vladimir,Capretta, Alfredo,Robertson, Al J.
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p. 3641 - 3644
(2007/10/03)
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- Synthesis, characterization and catalytic properties of SAPO-11, -31 and -41 molecular sieves
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Medium pore molecular sieves, SAPO-11, SAPO-31 and SAPO-41, have been synthesized using di-n-propylamine and diethylamine as the organic template. They have been characterized by various methods such as elemental analysis, X-ray powder diffraction, solid state MAS NMR spectroscopy, and FT-IR spectroscopy in the framework and hydroxyl regions. Catalytic activities of these materials in the esterification of phthalic anhydride with different alcohols have been studied. The catalytic activity of these material is in the order: SAPO-41> SAPO-11> SAPO-31.
- Venkatathri,Srivastava
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p. 1039 - 1043
(2007/10/03)
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- Fine particulate matter (PM) and organic speciation of fireplace emissions
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This paper presents a summary of fireplace particle size and organic speciation data gathered to date in an ongoing project. Tests are being conducted in a residential wood combustion (RWC) laboratory on three factory- built fireplaces. RWC wood smoke particles 10 μm (PM10) consist primarily of a mixture of organic compounds that have condensed into droplets; therefore, the size distribution and total mass are influenced by temperature of the sample during its collection. During the series 1 tests (15 tests), the dilution tunnel used to cool and dilute the stack gases gave an average mixed gas temperature of 47.3 °C and an average dilution ratio of 4.3. Averages for the PM2.5 (particles 2.5 μm) and PM10 fractions were 74 and 84%, respectively. For the series 2 tests, the dilution tunnel was modified, reducing the average mixed gas temperatures to 33.8 °C and increasing the average dilution ratio to 11.0 in tests completed to date. PM2.5 and PM10 fractions were 83 and 91%, respectively. Since typical winter time mixed gas temperatures would usually be less than 10 °C, these size fraction results (even from the series 2 tests) probably represent the lower bound; the PM10 and PM2.5 size fractions might be higher at typical winter temperatures. The particles collected on the first stage (cutpoint ? 11.7 μm) were light gray and appeared to include inorganic ash. Particles collected on the remainder of the stages were black and appeared to be condensed organics because there was noticeable lateral bleeding of the collected materials into the filter substrate. Total particulate emission rates ranged from 10.3 to 58.4 g/h; corresponding emission factors ranged from 3.3 to 14.9 g/kg of dry wood burned. A wide range of Environmental Protection Agency (EPA) Method 8270 semivolatile organic compounds were found in the emissions; of the 17 target compounds quantified, major constituents are phenol, 2-methylphenol, 4- methylphenol, 2,4-dimethylphenol, and naphthalene. An account is given on fireplace particle size and organic speciation data gathered to date in an ongoing project. Total particulate matter emission rates and the results of analyses for semivolatile organics in the emissions are discussed.
- Purvis, Carol R.,Mccrillis, Robert C.,Kariher, Peter H.
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p. 1653 - 1658
(2007/10/03)
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- Fe2(SO4)3·xH2O in synthesis: A convenient and efficient catalyst for the esterification of aromatic carboxylic acids with alcohols
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Fe2(SO4)3·xH2O has been used for the catalyst in the esterification of aromatic carboxylic acids with alcohols. The method offers mild reaction condition, easy work-up, and high yields of the esterification products.
- Zhang, Gui-Sheng
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p. 607 - 611
(2007/10/03)
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- Municipal solid waste incineration bottom ash: Characterization and kinetic studies of organic matter
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Bottom ash is the main solid residue (in weight) which is produced by municipal solid waste incineration (MSWI) facilities. To be reused in public works, it has to be stored previously a few months. This material is composed primarily of a mineral matrix but also contains unburnt organic matter. The mineral content and its change in the course of aging are relatively well- known, in contrast with the organic content. So in order to detect the phenomena responsible for changes in organic matter and their effects during aging, the concentrations of the main organic compounds previously characterized, the number of microorganisms, and the release of carbon dioxide were followed kinetically (over 13 months) in model laboratory conditions (mass, particle size, humidity, temperature, aerobiosis). The results showed that the aging process led to the natural biodegradation of the organic matter available in bottom ash, composed essentially of carboxylic acids and n-alkanes (steroids and PAH's to a lesser extent), and consequently that it would improve the bottom ash quality. Furthermore these results were confirmed by the study of aging Conducted in conditions used in the industrial scale (over 12 months).
- Dugenest,Combrisson,Casabianca,Grenier-Loustalot
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p. 1110 - 1115
(2007/10/03)
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- Process for producing carboxylic acid esters and catalysts therefor
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A process for producing carboxylic acid esters by the following steps: a) preparation of a reaction mixture containing an alcohol and a carboxylic acid and/or a carboxylic anhydride and/or a carboxylic acid ester and or a partially esterified carboxylic acid, b) heating of this mixture to the suitable reaction temperature in the presence of a solid polysiloxane insoluble in the reaction medium and having sulphonic acid groups with intensive thorough mixing accompanied by continuous separation of the reaction water which forms, wherein the polysiloxane used as the catalyst in modified by treatment with a soluble aluminum, titanium or zirconium compound, and the spherical particles thereof have a diameter of 0.01 to 3 mm, a specific surface of 0.1 to 1200 m2 /g, a specific pore volume of 0.01 to 6.0 ml/g and a bulk density of 50 to 1000 g/l.
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- An efficient general method for esterification of aromatic carboxylic acids
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Treatment of a variety of aromatic carboxylic acids with alcohols in the presence of thionyl chloride results in excellent yields of corresponding esters. This esterification system is compatible with a wide assortment of functional groups.
- Hosangadi, Bhaskar D.,Dave, Rajesh H.
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p. 6375 - 6378
(2007/10/03)
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- Homogeneous electron transfer catalysis of the electrochemical reduction of carbon dioxide. Do aromatic anion radicals react in an outer-sphere manner?
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Electrochemically generated anion radicals of aromatic nitriles and esters possess the remarkable property to reduce carbon dioxide to oxalate with negligible formation of carboxylated products. They may thus serve as selective homogeneous catalysts for the reduction of CO2 in an aprotic medium. The catalytic enhancement of the cyclic voltammetric peaks of these catalysts is used to determine the rate constant of the electron transfer from these aromatic anion radicals to CO2 as a function of the catalyst standard potential. Substituted benzoic esters allowed a particularly detailed investigation of the resulting activation-driving force relationship. Using 14 different catalysts in this series made it possible to finely scan a range of reaction standard free energies of 0.4 eV. Detailed analysis of the resulting data leads to the conclusion that the reaction is not a simple outer-sphere electron transfer. It rather consists in a nucleophilic addition of the anion radical on CO2, forming an oxygen (or nitrogen for the nitriles) - carbon bond, which successively breaks homolytically, generating the parent ester (or nitrile) and the anion radical of CO2, which eventually dimerizes to oxalate.
- Gennaro, Armando,Isse, Abdirisak A.,Savéant, Jean-Michel,Severin, Maria-Gabriella,Vianello, Elio
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p. 7190 - 7196
(2007/10/03)
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- Cosmetic composition
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A composition suitable for topical application to mammalian skin or hair for inducing, maintaining or increasing hair growth comprises: (i) a first chemical inhibitor chosen from proteoglycanase inhibitors, glycosaminoglycanase inhibitors, glycosaminoglycan chain cellular uptake inhibitors or mixtures thereof; and (ii) a cosmetically acceptable vehicle for the chemical inhibitor; provided that when the first chemical inhibitor is a weak inhibitor, such that a 1 mM aqueous solution of the inhibitor reduces proteoglycanase activity, glycosaminoglycanase activity or cellular uptake of glycosaminoglycan chains, by from 5 to 50%, in accordance with at least one of the assay tests as herein described, then there is also present in the composition a second chemical inhibitor and/or an activity enhancer. When minoxidil is the sole chemical inhibitor, then the activity enhancer is a penetration enhancer chosen from a limited number of materials, including certain esters and cationic polymers. The total amount of chemical inhibitor present in the composition is sufficient to increase hair growth in the rat, when said composition is applied topically thereto, by at least 10% more than that obtainable using a control composition from which the said inhibitors have been omitted.
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- The Esterification of Carboxylic Acid with Alcohol over Hydrous Zirconium Oxide
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The esterification of carboxylic acids with alcohols proceeded efficienly with hydrous zirconium oxide to give the corresponding esters in the vapor phase, in the liquid phase, and in an autoclave.The steric hindrance of carboxylic acids and alcohols affected the esterification by lowering the reactivity.With a rise in the reaction temperature, the conversion of the carboxylic acid increased.The dehydration of alcohols was prevented by using hydrous zirconium oxide in spite of the high reaction temperature.The reaction rate is first-order with respect to the concentration of the catalyst and an alcohol and is inversely proportional to thta of the carboxylic acid.Transesterification also proceeded efficiently.
- Takahashi, Kyoko,Shibagaki, Makoto,Matsushita, Hajime
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p. 2353 - 2361
(2007/10/02)
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- THE SIDE REACTIONS IN THE ESTERIFICATION OF PHTALIC ANHHYDRIDE WITH 2-ETHYLHEXANE-1-OL IN THE PRESENCE OF ORGANOTITANATES
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Using synthetic, chromatographic and spectral methods, we studied the side reactions accompanying the preparation of di-2-ethylhexyl phtalate from phtalic anhydride and 2-ethylhexane-1-ol in the presence of catalytic amounts of tetra-n-butyl titanate.The catalyst proper was titanium(IV) mono-2-ethylhexyl phtalate.The possibility of a simultaneous gas-chromatographic quantitative determination of mono-2-ethylhexyl phtalate, di-2-ethylhexyl phtalate, 2-ethylhexan-1-ol and tetra-n-butyl titanate, reported in literature, has been refuted.In the esterification catalysedby hydrated titanium dioxide homogeneous catalysis by the formed organotitanate was dominating.The dissolving of hydrated titanium dioxide in the esterification of phtalic anhydride with 2-ethylhexane-1-ol was studied polarographically.
- Novrocik, Jan,Novrocikova, Marta,Norek, Jiri,Koruna, Ivan,Ryska, Miroslav
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p. 253 - 266
(2007/10/02)
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