- Efficient Catalysts for the Green Synthesis of Adipic Acid from Biomass
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Green synthesis of adipic acid from renewable biomass is a very attractive goal of sustainable chemistry. Herein, we report efficient catalysts for a two-step transformation of cellulose-derived glucose into adipic acid via glucaric acid. Carbon nanotube-supported platinum nanoparticles are found to work efficiently for the oxidation of glucose to glucaric acid. An activated carbon-supported bifunctional catalyst composed of rhenium oxide and palladium is discovered to be powerful for the removal of four hydroxyl groups in glucaric acid, affording adipic acid with a 99 % yield. Rhenium oxide functions for the deoxygenation but is less efficient for four hydroxyl group removal. The co-presence of palladium not only catalyzes the hydrogenation of olefin intermediates but also synergistically facilitates the deoxygenation. This work presents a green route for adipic acid synthesis and offers a bifunctional-catalysis strategy for efficient deoxygenation.
- Deng, Weiping,Yan, Longfei,Wang, Binju,Zhang, Qihui,Song, Haiyan,Wang, Shanshan,Zhang, Qinghong,Wang, Ye
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supporting information
p. 4712 - 4719
(2021/01/20)
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- A cobalt-substituted Keggin-Type polyoxometalate for catalysis of oxidative aromatic cracking reactions in water
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Efficient detoxification of harmful benzene rings into useful carboxylic acids in water is indispensable for achieving a clean water environment. We report herein that oxidative aromatic cracking (OAC) reactions in water were achieved using a catalytic system with a cobalt-substituted Keggin-Type polyoxometalate (Co-POM) as a catalyst, an Oxone monopersulfate compound as a sacrificial oxidant and sodium bicarbonate as an additive under mild conditions. Sodium bicarbonate plays a crucial role in the selective OAC reactions by Co-POM using ethylbenzenesulfonate as a model substrate. The reactive species was characterized to be a cobalt(iii)-oxyl species based on 31P NMR, UV-vis spectroscopic, kinetic, and theoretical analyses. The electrophilicity of the cobalt(iii)-oxyl species was demonstrated by a linear relationship with a negative slope in the Hammett plots of initial rates obtained from the OAC reactions of m-xylenesulfonate derivatives. Besides, we have verified the degradation pathway of the OAC reactions using benzene as a model substrate in the catalytic system. The degradation was initiated by an electrophilic attack of the cobalt(iii)-oxyl species on benzene to yield phenol followed by producing catechol, muconic acid, maleic/fumaric acid, tartaric acid derivatives and formic acid on the basis of 1H NMR spectroscopic analysis.
- Hong, Dachao,Kitagawa, Yasutaka,Kon, Yoshihiro,Shimoyama, Yoshihiro,Tamura, Satoru
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p. 8042 - 8048
(2020/12/28)
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- Bimetallic AuPt/TiO2Catalysts for Direct Oxidation of Glucose and Gluconic Acid to Tartaric Acid in the Presence of Molecular O2
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Tartaric acid is an important industrial building block in the food and polymer industry. However, green manufacture of tartaric acid remains a grand challenge in this area. To date, chemical synthesis from nitric acid-facilitated glucose oxidation leads to only a one-pot aqueous-phase oxidation of glucose and gluconic acid using bimetallic AuPt/TiO2 catalysts in the presence of molecular O2, with ～50% yield toward tartaric acid at 110 °C and 2 MPa. Structural characterization and density functional theory (DFT) calculation reveal that the lattice mismatch between fcc Pt and bcc Au induces the formation of twinned boundaries in nanoclusters and Jahn-Teller distortion in an electronic field. Such structural and electronic reconfiguration leads to enhanced σ-activation of the C-H bond competing with π-πelectronic sharing of the C═O bond on the catalyst surface. As a result, both C-H (oxidation) and C-C (decarboxylation) bond cleavage reactions synergistically occur on the surface of bimetallic AuPt/TiO2 catalysts. Therefore, glucose and gluconic acid can be efficiently transformed into tartaric acid in a base-free medium. Lattice distortion-enhanced reconfiguration of the electronic field in Pt-based bimetallic nanocatalysts can be utilized in many other energy and environmental fields for catalyzing synergistic oxidation reactions.
- Ding, Jie,Jin, Xin,Lai, Linyi,Liu, Mengyuan,Sun, Yu,Wang, Jinyao,Xia, Qi,Yan, Hao,Yang, Chaohe,Zhang, Guangyu,Zhang, Wenxiang
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p. 10932 - 10945
(2020/11/23)
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- Electrochemical oxidation of amoxicillin on carbon nanotubes and carbon nanotube supported metal modified electrodes
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The electrolysis of amoxicillin (AMX) was carried out on CNT, Pt/CNT and Ru/CNT modified electrodes based on Carbon Toray in 0.1 M NaOH, 0.1 M NaCl and 0.1 M Na2CO3/NaHCO3 buffer (pH 10) media with the aim of studying the significance of two factors, electrode material and pH, on the oxidative degradation and mineralization of AMX. For this purpose, the electrolysis products were identified by HPLC-MS and GC–MS, and quantified by HPLC-UV-RID and IC. The highest carbon mineralization efficiency, corresponding to 30% of the oxidized AMX, was found for Pt/CNT modified electrode in carbonate buffer medium. Regarding to the AMX conversion, the results show that the effect of pH is higher than that of the electrode material. Principal component analysis allowed to determine the experimental parameters vs. product distribution relationship and to elucidate the oxidation pathways for the studied electrodes. The results show that the hydroxylation of the aromatic ring and the nitrogen atom play an important role on the efficient degradation of AMX.
- Ferreira, Marta,Kuzniarska-Biernacka, Iwona,Fonseca, António M.,Neves, Isabel C.,Soares, Olívia S.G.P.,Pereira, Manuel F.R.,Figueiredo, José L.,Parpot, Pier
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p. 322 - 331
(2019/07/10)
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- Quantitative Determination of Pt- Catalyzed d -Glucose Oxidation Products Using 2D NMR
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Quantitative correlative 1H-13C NMR has long been discussed as a potential method for quantifying the components of complex reaction mixtures. Here, we show that quantitative HMBC NMR can be applied to understand the complexity of the catalytic oxidation of glucose to glucaric acid, which is a promising bio-derived precursor to adipic acid, under aqueous aerobic conditions. It is shown through 2D NMR analysis that the product streams of this increasingly studied reaction contain lactone and dilactone derivatives of acid products, including glucaric acid, which are not observable/quantifiable using traditional chromatographic techniques. At 98% glucose conversion, total C6 lactone yield reaches 44%. Furthermore, a study of catalyst stability shows that all Pt catalysts undergo product-mediated chemical leaching. Through catalyst development studies, it is shown that sequestration of leached Pt can be achieved through use of carbon supports.
- Armstrong,Hirayama,Knight,Hutchings
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p. 325 - 335
(2019/01/04)
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- Decorated single-enantiomer phosphoramide-based silica/magnetic nanocomposites for direct enantioseparation
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The nano-composites Fe3O4SiO2(-O3Si[(CH2)3NH])P(O)(NH-R(+)CH(CH3)(C6H5))2 (Fe3O4SiO2PTA(+)) and Fe3O4SiO2(-O3Si[(CH2)3NH])P(O)(NH-S(-)CH(CH3)(C6H5))2 (Fe3O4SiO2PTA(-)) were prepared and used for the chiral separation of five racemic mixtures (PTA = phosphoric triamide). The separation results show chiral recognition ability of these materials with respect to racemates belonging to different families of compounds (amine, acid, and amino-acid), which show their feasibility to be potential adsorbents in chiral separation. The nano-composites were characterized by FTIR, TEM, SEM, EDX, XRD, and VSM. The VSM curves of nano-composites indicate their superparamagnetic property, which is stable after their use in the separation process. Fe3O4, Fe3O4SiO2, Fe3O4SiO2PTA(+) and Fe3O4SiO2PTA(-) are regularly spherical with uniform shape and the average sizes of 17-20, 18-23, 36-47 and 43-52 nm, respectively.
- Karimi Ahmadabad, Fatemeh,Pourayoubi, Mehrdad,Bakhshi, Hadi
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p. 27147 - 27156
(2019/09/12)
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- Aerobic oxidation of xylose to xylaric acid in water over pt catalysts
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Energy-efficient catalytic conversion of biomass intermediates to functional chemicals can make bio-products viable. Herein, we report an efficient and low temperature aerobic oxidation of xylose to xylaric acid, a promising bio-based chemical for the production of glutaric acid, over commercial catalysts in water. Among several heterogeneous catalysts investigated, Pt/ C exhibits the best activity. Systematic variation of reaction parameters in the pH range of 2.5 to 10 suggests that the reaction is fast at higher temperatures but high C C scission of intermediate C5-oxidized products to low carbon carboxylic acids undermines xylaric acid selectivity. The C C cleavage is also high in basic solution. The oxidation at neutral pH and 60 8C achieves the highest xylaric acid yield (64 %). O2 pressure and Pt amount have significant influence on the reactivity. Decar-boxylation of short chain carboxylic acids results in formation of CO2, causing some carbon loss; however, such decarboxyla-tion is slow in the presence of xylose. The catalyst retained comparable activity, in terms of product selectivity, after five cycles with no sign of Pt leaching.
- Sadula, Sunitha,Saha, Basudeb
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p. 2124 - 2129
(2018/10/20)
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- Rearrangements and Tautomeric Transformations of Heterocyclic Compounds in Homogeneous Reaction Systems Furfural–Н2О2–Solvent
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General information on the reactions of furfurals with hydrogen peroxide is given. We have discussed the Baeyer–Villiger rearrangement of furan 2-hydroxyhydroperoxides and tautomeric transformations with proton transfer of 2-hydroxyfuran and β-formylacrylic acid formed in a homogeneous reaction system furfural–Н2О2–solvent under the catalysis with the formed acids. The factors affecting these rearrangements and tautomeric transformations as well as their specificity in comparison with benzene type compounds, and the pathway of the reactions of furan aldehydes with Н2О2 in water have been analyzed. Ketoenol tautomerism of cyclic hemiacetal form of β-formylacrylic acid leading to its transformation into succinic anhydride has been described for the first time.
- Badovskaya,Poskonin
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p. 1568 - 1579
(2018/11/10)
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- Synthetic method of 2,3-dihydrobutanedioic acid drug intermediate
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The invention discloses a synthetic method of a 2,3-dihydrobutanedioic acid drug intermediate. The synthetic method comprises the following steps: adding 1,4-dibromo-2,3-dimethoxy-butanedial and a heptane solution into a reaction container, controlling the stirring speed to be 170 to 190 rpm, increasing the temperature to be 40 to 46 DEG C, adding a water solution and dimethyl sulfoxide, adding adioctyl sebacate solution within 20 to 40 min in batches, and continuously reacting for 50 to 80 min; increasing the temperature to be 55 to 62 DEG C, adding a potassium bromide solution and zinc acetate powder, continuously reacting for 2 to 3 h, reducing the temperature to be 10 to 16 DEG C, leaving to stand for 30 to 50 min, adding a sodium nitrate solution, layering the solution to separate anoil layer, washing with a 3-hexyl alcohol solution for 30 to 50 min, carrying out recrystallization in a cyclopentanecarboxylic acid solution, and carrying out dehydration by a dehydrating agent to obtain the finished product 2,3-dihydrobutanedioic acid.
- -
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Paragraph 0017-0019; 0021-0023; 0024-0027
(2018/07/30)
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- R-1-aminoindan preparation method
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The invention discloses a splitting preparation method of R-1-aminoindan. According to the splitting preparation method, 1-aminoindan is used as a raw material, L-mandelic acid is used as a splitting agent, a reaction is performed in a suitable solvent to obtain 1-aminoindan L-mandelate, crystallization separation is performed to obtain R-1-aminoindan L-mandelate, and the R-1-aminoindan L-mandelate is subjected to re-crystallization and alkalization to obtain R-1-aminoindan, wherein the reaction and re-crystallization mother liquor is evaporated to remove the alcohol, the obtained liquid and other solutions containing the L-mandelate are mixed, and the obtained mixed solution is subjected to acidification, extraction with an organic solvent, concentration and other operations so as to recover the L-mandelic acid. According to the present invention, the method has advantages of mild conditions, simple operation, high product yield, high optical purity of the product, splitting agent recycling and the like, and is suitable for the industrial production of R-1-aminoindan.
- -
-
Paragraph 0007; 0010
(2017/12/28)
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- Degradation of the Cellulosic Key Chromophore 5,8-Dihydroxy-[1,4]-naphthoquinone by Hydrogen Peroxide under Alkaline Conditions
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5,8-Dihydroxy-[1,4]-naphthoquinone (DHNQ) is one of the key chromophores in cellulosic materials. Its almost ubiquitous presence in cellulosic materials makes it a target molecule of the pulp and paper industry's bleaching efforts. In the presented study, DHNQ was treated with hydrogen peroxide under alkaline conditions at pH 10, resembling the conditions of industrial hydrogen peroxide bleaching (P stage). The reaction mechanism, reaction intermediates, and final degradation products were analyzed by UV/vis, NMR, GC-MS, and EPR. The degradation reaction yielded C1-C4 carboxylic acids as the final products. Highly relevant for pulp bleaching are the findings on intermediates of the reaction, as two of them, 2,5-dihydroxy-[1,4]-benzoquinone (DHBQ) and 1,4,5,8-naphthalenetetrone, are potent chromophores themselves. While DHBQ is one of the three key cellulosic chromophores and its degradation by H2O2 is well-established, the second intermediate, 1,4,5,8-naphthalenetetrone, is reported for the first time in the context of cellulose discoloration.
- Zwirchmayr, Nele Sophie,Hosoya, Takashi,Henniges, Ute,Gille, Lars,Bacher, Markus,Furtmüller, Paul,Rosenau, Thomas
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p. 11558 - 11565
(2017/11/10)
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- A D-ethyl ester recovery and use in the production of L-(+)-tartaric acid method
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The invention discloses a method for recycling and reusing L-(+)-tartaric acid in production of D-p-methyl sulfone phenyl ethyl serinate. The method comprises the following steps: (1), a L-(+)-calcium tartrate dihydrate crystal is recovered from L-ethyl ester mother liquor; (2), an L-(+)-tartaric acid double brine solution is recovered from D-p-methyl sulfone phenyl ethyl serinate mother liquor; (3), L-(+)-tartaric acid double hydrochlorination is performed; (4), L-(+)-tartaric acid is recovered through L-(+)-tartaric acid single hydrochlorination; and (5), processes of vacuum concentration, crystallization, separation, drying and the like are performed. An insert organic solvent is used for replacing a conventional water phase method to recover L-(+)-tartaric acid, the possibility of side reaction is avoided, the purity and specific rotation of a product can both reach the raw material quality standard, and L-(+)-tartaric acid can be directly and circularly applied to chiral resolution of D-p-methyl sulfone phenyl ethyl serinate. Different recovery processing technologies are adopted for different mother liquor of two components in the production process of D-p-methyl sulfone phenyl ethyl serinate, the product quality is improved remarkably, the whole recovery condition is mild, and the operation is simpler and easy to control.
- -
-
Paragraph 0045-0052
(2017/04/29)
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- Selective oxidation of 5-keto-d-gluconate to l-(+)-tartaric acid on transition metal chelate catalyst
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The selective oxidation of 5-keto-d-gluconate (5-KGA) to l-(+)-tartaric acid (L-TA) was performed under mild conditions in an alkaline carbonate buffer, employing various transition metal catalysts. CuSO4·5H2O was found to be an efficient catalyst, providing a molar conversion rate and selectivity for L-TA of 74. 58% and 76.18%, respectively. Based on an analysis of the reaction process using UV-Vis spectroscopy, coordination number determination and functional group detection, a mechanism for the metal chelate catalytic oxidation of 5-KGA to L-TA is proposed, and this mechanism is shown to be completely different from that associated with catalysis by vanadate.
- Yuan, Jianfeng,Wu, Mianbin,Lin, Jianping,Yang, Lirong
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p. 251 - 257
(2016/07/06)
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- Aqueous Photochemistry of Glyoxylic Acid
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Aerosols affect climate change, the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. While the formation of secondary organic aerosols (SOA) from gas phase precursors is relatively well understood, studying aqueous chemical reactions contributing to the total SOA budget is the current focus of major attention. Field measurements have revealed that mono-, di-, and oxo-carboxylic acids are abundant species present in SOA and atmospheric waters. This work explores the fate of one of these 2-oxocarboxylic acids, glyoxylic acid, which can photogenerate reactive species under solar irradiation. Additionally, the dark thermal aging of photoproducts is studied by UV-visible and fluorescence spectroscopies to reveal that the optical properties are altered by the glyoxal produced. The optical properties display periodicity in the time domain of the UV-visible spectrum of chromophores with absorption enhancement (thermochromism) or loss (photobleaching) during nighttime and daytime cycles, respectively. During irradiation, excited state glyoxylic acid can undergo α-cleavage or participate in hydrogen abstractions. The use of 13C nuclear magnetic resonance spectroscopy (NMR) analysis shows that glyoxal is an important intermediate produced during direct photolysis. Glyoxal quickly reaches a quasi-steady state as confirmed by UHPLC-MS analysis of its corresponding (E) and (Z) 2,4-dinitrophenylhydrazones. The homolytic cleavage of glyoxylic acid is proposed as a fundamental step for the production of glyoxal. Both carbon oxides, CO2(g) and CO(g) evolving to the gas-phase, are quantified by FTIR spectroscopy. Finally, formic acid, oxalic acid, and tartaric acid photoproducts are identified by ion chromatography (IC) with conductivity and electrospray (ESI) mass spectrometry (MS) detection and 1H NMR spectroscopy. A reaction mechanism is proposed based on all experimental observations.
- Eugene, Alexis J.,Xia, Sha-Sha,Guzman, Marcelo I.
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p. 3817 - 3826
(2016/06/13)
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- D-ethyl ester recovery and use in the production of L-(+)-tartaric acid method
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The invention discloses a method for recovering and mechanically applying L-(+)-tartrate in D-ethyl ester production, which comprises the following steps: 1)obtaining a L-(+)-tartrate solution; 2)recovering L-(+)-calcium tartrate dehydrate; 3)acidifying; 4)performing pressure reduction and condensation; and 5)crystallizing, separating and drying. The method of the invention employs an inertia organic solvent, takes a solvent method to replace a water phase method to recover L-(+)-tartrate, key points of control temperature, time, centrifugation and vacuum degree are realized, the product yield is high, the purity and specific rotation of the recovered L-(+)-tartrate product accord with quality requirement, quality standard of the L-(+)-tartrate raw material can be reached, and the method can be used for chiral resolution of D-ethyl ester, recovery and mechanical application of L-(+)-tartrate can be realized, production cost is reduced, and the method is suitable for industrial production.
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-
Paragraph 0040-0042
(2017/05/25)
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- Characterization and reactivity of Mn-Ce-O composites for catalytic ozonation of antipyrine
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Mn-Ce-O composites were prepared by a redox-precipitation method and used as a catalyst for ozonation of antipyrine (AP) in aqueous solution. The phase composition, surface area and electron transfer ability of the products are dependent on the molar ratio of precursors. Mn-Ce-O(8/2) exhibited the highest activity for the degradation and mineralization of AP with ozone, which can be attributed to its high electron transfer ability. The decomposition of ozone into .OH can be accelerated through the electron transfer between ozone and catalyst. The refractory intermediates in ozonation and catalytic ozonation were identified and the catalytic performances of Mn-Ce-O(8/2) for these intermediates were also investigated. The hydroxyl radical reaction played an important role in the degradation of the refractory intermediates, and the contribution of surface reactions was strengthened with decreasing pH. A possible mechanism for the catalytic ozonation of AP was proposed.
- Xing, Shengtao,Lu, Xiaoyang,Ren, Limei,Ma, Zichuan
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p. 60279 - 60285
(2015/07/27)
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- One-pot synthesis of micro/nano structured β-Bi2O3 with tunable morphology for highly efficient photocatalytic degradation of methylparaben under visible-light irradiation
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β-Bi2O3 micro/nanostructures with tunable morphologies were synthesized via a one-pot solvothermal-calcining route, and their photocatalytic activity toward degrading methylparaben (MeP, a widely used preservative with estrogenic activity) was evaluated under visible-light (λ ≥ 420 nm) irradiation. The formation process of β-Bi2O3 catalysts can be described as reduction of Bi3+ through a solvothermal reaction, followed by oxidization of metal Bi via calcination in air. During this process, the organic reductants (single or a mixture of ethylene glycol, d-fructose, and ascorbic acid) play important roles in determining the final morphologies and structures of the materials. Photocatalytic tests reveal that MeP can be effectively degraded and mineralized by using synthetic β-Bi2O3 catalysts, and the reaction rate constant of an optimum sample is more than 25 and 160 times faster than a commercial Bi2O3 and synthetic N-TiO2, respectively. The superior photocatalytic activity of the optimum product is ascribed to its pure beta phase with a narrower band gap, good absorption of visible light, more efficient separation of electrons and holes, relatively higher BET specific surface area, and three-dimensional architectures, which favor more surface active sites and easier mass and photoinduced charge transportations. In addition, the main reactive oxygen species and possible degradation intermediates were detected, and the results suggest that photogenerated holes and superoxide radicals are the predominant species in the photochemical oxidation process.
- Xiao, Xin,Hu, Ruiping,Tu, Shunheng,Zheng, Chunxia,Zhong, Huan,Zuo, Xiaoxi,Nan, Junmin
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p. 38373 - 38381
(2015/07/28)
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- Identification of low molecular weight organic acids by ion chromatography/hybrid quadrupole time-of-flight mass spectrometry during Uniblu-A ozonation
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RATIONALE: The balance of organic nitrogen and sulfur during ozonation of organic pollutants often shows a lack of complete mineralization. It follows that polar and ionic byproducts are likely to be present that are difficult to identify by liquid chromatography/mass spectrometry (LC/MS). METHODS: The structural elucidation of low molecular weight organic acids arising from Uniblu-OH ozonation has been investigated by ion chromatography/electrospray tandem mass spectrometry (IC/ESIMS/MS) employing a quadrupole timeofflight mass spectrometer. Unequivocal elemental composition of the byproducts was determined by a combination of mass accuracy and high spectral accuracy. RESULTS: The employed identification strategy was demonstrated to be a powerful method of unequivocally assigning a single chemical composition to each identified compound. The exact mass measurements of [M-H]- ions allowed the elemental formulae and related structures of eighteen byproducts to be determined confidently. The main degradation pathways were found to be decarboxylation and oxidation. The experimental procedure allowed the identification of both nitrogen- and sulfur-containing organic acid by-products arising from Uniblu-OH ozonation. CONCLUSIONS: The obtained results are of environmental relevance for the balance of organic nitrogen and sulfur during the ozonation of organic pollutants due to the lack of complete mineralization of the compounds containing these atoms. Copyright 2012 John Wiley & Sons, Ltd. Copyright
- Amorisco, Apollonia,Locaputo, Vito,Pastore, Carlo,Mascolo, Giuseppe
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p. 187 - 199
(2013/02/23)
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- USE OF CAFTARIC ACID AND LACTIC BACTERIUM IN FOOD SUPPLEMENT FOR REGULATING SKIN PIGMENTATION
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The present invention relates generally to the field of cosmetic and/or food supplement. More specifically, the present invention aims to provide the use of at least an ingredient containing caftaric acid and/or derivatives and a micro-organism and/or an enzyme capable of hydrolyzing caftaric acid and/or derivatives thereof to generate tartaric and/or caffeic acid, for improving skin tone and preventing and/or treating hyper-pigmentation of skin and/or skin color imperfections such as age-spots and other skin disorders characterized by abnormal pigments. Also, the present invention aims at providing a skin lightening agent.
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-
Paragraph 0089; 0090
(2013/04/24)
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- COSMETIC COMPOSITION COMPRISING AT LEAST ONE ELASTOMERIC POLYURETHANE AND AT LEAST ONE CATIONIC POLYMER
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Provided is a cosmetic composition comprising, in a cosmetically acceptable medium, at least one film-forming elastomeric, anionic polyurethane, and at least one cationic polymer, as well as a method for the styling of the hair comprising applying this composition to the hair.
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- Zwitterionic and anionic multinuclear pentacoordinate silicon(IV) complexes with bridging (R,R)-tartrato(4-) ligands and SiO5 skeletons: Synthesis and reactivity in aqueous solution
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Two nutrients in one molecule: A zwitterionic λ5Si, λ5Si′-disilicate (1) was synthesized and characterized. It contains ligands that exclusively derive from natural products ((R,R)-tartaric acid, choline). Hydrolysis of 1 yields 2, which shows a remarkable kinetic stability in water. Upon dissolution of 1 and 2 in water, the nutrients choline and orthosilicic acid are formed by hydrolysis Copyright
- Theis, Bastian,Weiss, Joerg,Lippert, W. Peter,Bertermann, Ruediger,Burschka, Christian,Tacke, Reinhold
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body text
p. 2202 - 2206
(2012/04/10)
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- Supramolecular metathesis: Co-former exchange in co-crystals of pyrazine with (R,R)-, (S,S)-, (R,S)- and (S,S/R,R)-tartaric acid
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Co-crystals of dextro-(R,R), levo-(S,S), meso-(R,S) and racemic (R,R-S,S)-tartaric acid with pyrazine were obtained by manual kneading and slurry experiments; subsequent reactions in the solid state between these co-crystals and the various forms of tartaric acid in the solid state and via slurry show that co-former exchange takes place according to the sequence of stability [(R,S)-ta]2·py > (S,S/R,R)-ta·py > (R,R)-ta·py or (S,S)-ta·py.
- Braga, Dario,Grepioni, Fabrizia,Lampronti, Giulio I.
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experimental part
p. 3122 - 3124
(2012/02/15)
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- PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
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The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
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-
-
- Synthesis and properties of crosslinked chiral nanoparticles via RAFT miniemulsion polymerization
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Crosslinked chiral nanoparticles were successfully synthesized via reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization of 6-O-p-vinylbenzyl-1,2:3,4di-O-isopropylidene-D-galactopyranose (VBPG) using linear poly(VBPG) as the macro-RAFT agent. The polymerization of VBPG in the absence of crosslinker was first studied and the kinetic results showed that the molecular weights of the obtained poly(VBPG) increased linearly with the monomer conversion and was in good consistency with the corresponding theoretical ones while there remained a relative narrow polydisperslty. The effect of the amount of crosslinker, divlnylbenzene, on the nanoparticle size and chiral separation properties of the obtained nanoparticles were investigated in detail using four racemates ±-3-Amino-1,2propanediol, D,L-arablnose, D,L-tartaric acid, and D,L-mandelic acid.
- Xu, Wenliang,Cheng, Zhenping,Zhang, Lifen,Zhang, Zhengbiao,Zhu, Jian,Zhou, Nianchen,Zhu, Xiulin
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experimental part
p. 1324 - 1331
(2011/02/26)
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- Improved preparative electrochemical oxidation of d-glucose to d-glucaric acid
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The 2,2,6,6-tetramethyl-1-piperidinyloxy free radical (TEMPO) mediated electrochemical oxidation of d-glucose to d-glucaric acid on a synthetically useful scale is reported. Using TEMPO and a graphite felt anode combined with a stainless steel cathode, d-glucose was oxidized under different conditions (pH, temperature, co-oxidant), and the reaction outcomes were analyzed. Optimized conditions for such oxidation are provided along with few new interesting results unique to this reaction, such as the appearance of a novel triacid.
- Ibert, Mathias,Fuertès, Patrick,Merbouh, Nabyl,Fiol-Petit, Catherine,Feasson, Christian,Marsais, Francis
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experimental part
p. 3589 - 3594
(2010/07/08)
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- Encapsulated Vaccinium Extracts with Balanced Gastrointestinal Release
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The invention relates to Vaccinium fruit extracts, related preparations, production methods and uses.
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- Determination and evaluation of the second-order rate constants for the oxidation of maleic and fumaric acid derivatives with alkaline potassium permanganate
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The second-order rate constants for the oxidation of maleic (Z-butenedioc) and fumaric (E-butenedioc) acid derivatives by potassium permanganate at pH 13 were determined. These constants varied by a factor of 104. The results suggested that the rates of attack of the permanganate ion on the double bonds were largely governed by steric factors with electrostatic and electronic effects playing only a minor role.
- Abdul Halim, S. Rahimah,French, Gilly M.,Hughes, Alexandra J.N.,Prankerd Smith, C.A. Olivia,Hughes, D.E. Peter
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experimental part
p. 188 - 190
(2009/11/30)
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- Magnesium-mediated intramolecular reductive coupling: A stereoselective synthesis of C2-symmetric 3,4-bis-silyl-substituted adipic acid derivatives
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Chiral C2-symmetric 3,4-bis-silyl-substituted adipic acid derivatives have been synthesised by a Mg/trimethylsilyl chloride-mediated intramolecular reductive coupling of symmetrical disiloxanes of β-silylacrylic acid N-oxazolidinone derivatives
- Kundu, Pintu K.,Ghosh, Sunil K.
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experimental part
p. 4611 - 4621
(2009/12/08)
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- Reaction pathways of glucose oxidation by ozone under acidic conditions
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The ozonation of d-glucose-1-13C, 2-13C, and 6-13C was carried out at pH 2.5 in a semi-batch reactor at room temperature. The products present in the liquid phase were analyzed by GC-MS, HPAEC-PAD, and 13C NMR s
- Marcq, Olivier,Barbe, Jean-Michel,Trichet, Alain,Guilard, Roger
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experimental part
p. 1303 - 1310
(2009/12/01)
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- Separation of Stereoisomeric N,N-Dialkylamino-2Alkyl-3-Hydroxy-3-Phenylalkanes
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The invention concerns a method for the isolation of a stereoisomer from a mixture comprising the two stereoisomers of the general formulae (I-A) and (I-A′) and/or the two stereoisomers of the general formulae (I-B) and (I-B′) in which R1, R2 and R3, identical or different, are selected from the group consisting of —H, —F, —Cl, —C1-C6-alkyl, —S—C1-C6-alkyl, —OH, —O—C1-C6-alkyl, —O—C1-C6-alkylenephenyl, —OCO—C1-C6-alkyl, —OCON(C1-C6-alkyl)2 and —O—SiR8R9R10 (in which R8, R9 and R10, identical or different, are —C1-C6-alkyl or -phenyl);R4 is —H or —C1-C6-alkyl;R5 is —C1-C6-alkyl; andR6 and R7, identical or different, are —H or —C1-C6-alkyl; or their salts with organic or inorganic acids; comprising the step (a) manipulating the mixture ratio of the stereoisomers in the mixture so that at least one of the stereoisomers is present in an enantiomeric excess.
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- Chiral mono boronic acid as fluorescent enantioselective sensor for mono α-hydroxyl carboxylic acids
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(Graph Presented) New mono boronic acid was found to be an enantioselective fluorescent chemosensor for mono α-hydroxyl carboxylic acids, such as mandelic acid and lactic acid. The chiral sensor shows lower background fluorescence, higher fluorescence enh
- Chi, Lina,Zhao, Jianzhang,James, Tony D.
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p. 4684 - 4687
(2008/09/21)
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- Influence of the temperature on heat effects of acid-base interactions in aqueous solutions of succinic and tartaric acids
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The heat effects of interactions of solutions of succinic and tartaric acids with solutions of HNO3 and KOH or LiOH are measured over the temperature range 288.15-308.15 K at ionic strengths of 0.5, 1.0, and 1.5 (KNO3 or LiNO3). The heat effects of dissociation of the acids are calculated using a Pentium-150 PC with HEAT and RRSU universal software packages. The thermodynamic characteristics of the processes of stepwise dissociation of the oxyacids are determined. The influence of the temperature on the heat effects of the processes of stepwise dissociation of succinic and tartaric acids is discussed. Nauka/Interperiodica 2007.
- Kochergina,Vasil'ev,Krutov,Krutova
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p. 910 - 916
(2008/02/12)
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- Using indicator-displacement assays in test strips and to follow reaction kinetics
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(Matrix Presented) An indicator-displacement assay was used to study the kinetics of reactions that produce tartrate. The same assay was also found to be useful in developing tartrate test strips, by coating filter paper with the same receptor and indicator.
- Nguyen, Binh T.,Wiskur, Sheryl L.,Anslyn, Eric V.
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p. 2499 - 2501
(2007/10/03)
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- Protease inhibitors and their pharmaceutical uses
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The present invention refers to synthetic protease inhibitors having an axis of symmetry C2 or pseudo-C2 characterised by possessing, in the central portion: (1) preferably, a dihydroxyethylene function, which is isosteric with a peptidic bond; (2) a peptidemimetic bridge between the two nitrogens of the main chain and (3) radicals capable of mimetising amino acids. These new protease inhibitors are a base for the preparation of anti-viral formulations capable of inhibiting HIV virus proliferation.
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- L-DOPA ethyl ester salts and uses thereof
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The present invention provides non-hygroscopic, crystalline salts of levodopa ethyl ester (LDEE), wherein the salt is the octanoate salt, the myristate salt, the succinate salt, the succinate dihydrate salt, the fumarate salt or the fumarate dihydrate salt of levodopa ethyl ester. The subject invention also encompasses compositions comprising a levodopa ethyl ester salt and a carrier and processes for making these compositions. In addition, the subject invention concerns pharmaceutical compositions comprising a levodopa ethyl ester salt and a pharmaceutically acceptable carrier, as well as processes for making these pharmaceutical compositions. Furthermore, the subject invention includes methods of treating a subject afflicted with Parkinson's disease, senile dementia, dementia of the Alzheimer's type, a memory disorder, depression, hyperactive syndrome, an affective illness, a neurodegenerative disease, a neurotoxic injury, brain ischemia, a head trauma injury, a spinal trauma injury, schizophrenia, an attention deficit disorder, multiple sclerosis and seizures by the administration of levodopa ethyl ester salts.
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- 4-AcNH-Tempo-catalyzed oxidation of aldoses to aldaric acids using chlorine or bromine as terminal oxidants
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The 4-AcNH-TEMPO-catalyzed oxidation of D-glucose to D-glucaric acid using elemental chlorine or bromine as the terminal oxidant is reported. The pH and temperature of the reactions were closely controlled to be between 0-5 deg C and pH 11.5, respectively. Spectroscopically (1H NMR) determined yields of glucarate were greater than 90 percent; yields of crystalline monopotassium D-glucarate (or disodium D-glucarate), isolated and purified by precipitation, were between 70 and 85 percent. Oxidations of mannose to mannaric acid and galactose to mucic acid were also demonstrated.
- Merbouh, Nabyl,Bobbitt, James M.,Brueckner, Christian
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- Hair treatment composition
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The present invention relates to hair treatment compositions comprising a hairsetting polymer together with a salt of the formula I[A—(X)n]n?.[HmB]m+where A, X, B, n and m are as defined in the description. The novel hair treatment compositions possess improved ease of washing out, smoothness and transparency and can be formulated with a reduced VOC content.
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- Plaster retarding composition
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The present invention is related to a calcium tartrate plaster retarding composition, characterised in that it has a mean particle size lower than 30 μm,The present invention is also related to the plaster comprising said composition and to the preparation process of said composition.
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- Acylated anthocyanins from the blue-violet flowers of Anemone coronaria
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Five polyacylated anthocyanins were isolated from blue-violet flowers of Anemone coronaria 'St. Brigid'. They were identified as delphinidin 3-O-[2-O-(2-O-(trans-caffeoyl)-β-D-glucopyranosyl)-6-O- (malonyl)-β-D-galactopyranoside]-7-O-[6-O- (trans-caffeoyl
- Saito, Norio,Toki, Kenjiro,Moriyama, Hidekazu,Shigihara, Atsushi,Honda, Toshio
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p. 365 - 373
(2007/10/03)
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- Determination of the side-products formed during the nitroxide-mediated bleach oxidation of glucose to glucaric acid
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The side products formed in the TEMPO-mediated oxidation of glucose to glucaric acid were determined by GC. Next to glucaric acid, gluconic acid, the intermediate in the oxidation, the degradation products, oxalic acid, tartronic acid, meso-(erythraric) a
- Ibert, Mathias,Marsais, Francis,Merbouh, Nabyl,Brückner, Christian
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p. 1059 - 1063
(2007/10/03)
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- Photocatalytic degradation of dyes in water: Case study of indigo and of indigo carmine
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The TiO2/UV photocatalytic degradations of indigo and of indigo carmine have been investigated both in aqueous heterogeneous suspensions and in the solid state. In addition to prompt removal of the color, TiO2/UV-based photocatalysis
- Vautier, Manon,Guillard, Chantal,Herrmann, Jean-Marie
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- Water-soluble solid-phase ironing aid freshening composition tablets consisting of same for use in the steam chamber of an iron and process for preparing and utilizing the same
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Described is a water-soluble solid-phase ironing aid-freshening composition for use in forming controllably dimensioned tablets, which have controlled weights and densities and which are conveniently added to the water-containing steam chamber of a steam iron. The use of the tablets produced from the composition enables textiles which are ironed to be freshened and de-wrinkled. The composition includes (i) a support substance; (ii) a tablet binder substance; and (iii) a fragrance composition and, optionally, a silicone resin, a chelating agent and/or a surfactant.
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- Process for the continuous production of basic cyclic optically active alpha - amino acids
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PCT No. PCT/EP96/04073 Sec. 371 Date Mar. 24, 1998 Sec. 102(e) Date Mar. 24, 1998 PCT Filed Sep. 18, 1996 PCT Pub. No. WO97/12881 PCT Pub. Date Apr. 10, 1997The invention pertains to a process for the continuous production of basic cyclic optically active alpha -amino acids of general formula (I) by continuous racemate splitting via diastereomeric salt pairs with re-racemisation of the residual amino acid or amino acid derivative in the mother liquid with the aid of an optically active acid.
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- Method of preparing tartaric acid
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A method of preparing tartaric acid in which 5-ketogluconate is oxidized in a carbonate buffer at an alkaline pH preferably in the range of 8 to 10 using vanadate.
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- Intravaginal preparation containing physiologically active peptide
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The present invention relates to an improved intravaginal preparation containing a physiologically active peptide, which comprises a physiologically active peptide, a sucrose fatty acid ester and an organic acid with a pharmaceutically acceptable carrier or diluent, by which the physiologically active peptide can be absorbed safely and efficiently.
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- Catalytic oxidation of furan and hydrofuran compounds. 4. Oxidation of furfural by hydrogen peroxide in the presence of sodium molybdate
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The oxidation of furfural by an aqueous solution of hydrogen peroxide in the presence of sodium molybdate was studied for the first time. Its final products are 2(5H)-furanone and also tartaric, malic, and succinic acids. The process takes place through the formation of peroxide and carbonyl compounds. Kinetic curves for the consumption of the reagents and the accumulation of the reaction products were obtained. In direction oxidation in this system differs substantially from the previously studied reactions of furfural with an aqueous solution of hydrogen peroxide without a catalyst and in the presence of selenium and vanadium compounds. 1999 Kluwer Academic/Plenum Publishers.
- Grunskaya,Badovskaya,Poskonin,Yakuba
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p. 775 - 780
(2007/10/03)
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- A new B-Z oscillator with a modified control mechanism
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Osculations in fructose + BrO3- + Ce4+ + H2SO4 system without any bromine scavenger have been observed in the range 0.035-0.7 M fructose in a batch reactor as well as continuous stirred tank reactor (CSTR). Analysis of reaction product was done by TLC, UV, NMR and HPLC. The oscillations are insensitive to Br concentration even upto 10-2 M. [Br-] and [Br2] have been estimated at several stages, of oscillations in a typical case. At the maxima, [Br-] is found to be of the order of 10-5 M which is much higher than the critical Br- concentration. Tartaric acid is found to promote oscillations when added to non-oscillating fructose system although no oscillations are observed in tartaric acid + BrO3- + Ce4+ +H2SO4 system of a similar concentrations. Within a certain range of fructose concentration, damped complex oscillations are observed in the batch reactor. In CSTR aperiodic oscillations are observed at higher [fructose] with decreasing flow rates although sustained periodic oscillations are observed at low [fructose]. In a particular concentration range two types of oscillations in fructose (F) + acetone oscillator separated by time pause have also been observed in the batch reactor. Oscillations that occur before time pause (first type oscillations) are insensitive to addition of Br- upto 10-2 M and are similar to that observed in the corresponding fructose oscillator without acetone. On the other hand, oscillations that occur after time pause (second type oscillations) are stopped when [Br-] ≈ 10-3 M. The colour of reaction mixture is intense brown during first type of oscillations. It changes from colourless to yellow during second type of oscillations. At higher concentration of fructose, only oscillations observed before time pause are obtained while at lower concentration of fructose only the oscillations observed after time pause are obtained but in between sequential oscillations are observed. Computer simulation studies have also been undertaken. Br--control mechanism is unable to predict oscillations as such, whereas a mechanism based on free-radical control as well as Br--control predicts oscillations. Polymerisation studies and ESR studies have been undertaken to ascertain the formation of free radicals.
- Rastogi,Khare, Ravi,Misra,Srivastava, Sangita
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- Effects of grinding and humidification on the transformation of conglomerate to racemic compound in optically active drugs
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The effects of grinding and humidification on the transformation of conglomerate to racemic compound have been investigated by X-ray powder diffraction (XPD), differential scanning calorimetry (DSC) and infrared (IR) spectroscopy for leucine, norleucine, valine, serine, tartaric acid and malic acid. Racemic physical mixtures were prepared by physical mixing of equimolar quantities of D and L crystals using a mortar and pestle. Ground mixtures were obtained by grinding the physical mixtures with a vibrational mill. Humidification was performed by storing the physical mixtures and the ground mixtures in a desiccator containing saturated aqueous salt solutions at 40(o)C. When physical mixtures of malic acid, tartaric acid and serine were ground, the XPD peaks of the racemic compounds were observed. The XPD patterns of humidified physical mixtures of these compounds also showed the formation of the racemic compounds. This indicated that grinding or humidification of malic acid, tartaric acid and serine induced the transformation of conglomerate to racemic compound crystals. When, on the other hand, the physical mixtures of valine, leucine and norleucine were ground, peaks of racemic compounds were not detected in the XPD pattern. After humidification of the ground mixtures of valine, leucine and norleucine, however, the XPD peaks of racemic compounds were observed. DSC and IR studies revealed consistent results. We concluded that grinding or humidification of malic acid, tartaric acid and serine could induce the transformation of a conglomerate to racemic compound. In contrast, humidifying after grinding was needed to bring about the transformation in leucine, norleucine and valine.
- Piyarom, Sujimon,Yonemochi, Etsuo,Oguchi, Toshio,Yamamoto, Keiji
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p. 384 - 389
(2007/10/03)
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- Synthesis of ferrocenyl phenyltropane analogs and their radio-transformation to technetium neuroprobes for mapping monoamine reuptake sites
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Neuroprobes that include rhenium, manganese, and technetium for use in mapping monoamine reuptake sites are disclosed. Non-radioactive tricarbonylrheniumcyclopentadienyl (TRCp) or non-radioactive tricarbonylmanganesecyclopentadienyl (TMCp) phenyltropane analogs are synthesized for use as testing surrogates for radioactive technetium congeners. Ferrocenyl analogs of phenyltropane are disclosed as useful precursors for the preparation of novel tricarbonyltechnetiumcyclopentadienyl (TTCp) phenyltropane analogs in radioactive form.
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