- Reduction Potentials and Exchange Reactions of Thiyl Radicals and Disulfide Anion Radicals
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Redox equilibria between RS. and -S-S-- radicals, and between these types of radical and phenoxyl and chlorpromazine (ClPz.2+) radicals, have been investigated in aqueous solutions at pHs over the range 6-10 to obtain a self-consistent set of redox potentials for the reactions PhO. + H+ + e- = PhOH (4), RSS.R + 2H+ + e- = 2RSH (11), and RS. + H+ + e- = RSH (18), in sulfur systems with alkyl R groups.Absolute standard potentials were calculated on the of E0 = 0.83 V for the chlorpromazine couple.The results for E04 (=1.35 +/- 0.02 V) and E018 (=1.33 +/- 0.02 V) were in agreement with values calculated from thermodynamic data within the known uncertainties.E018 was found to exhibit a falloff when electron-rich groups, such as the two methyls of penicillamine or the CO2- of β-mercaptoacetic acid, were present on the carbon adjacent to the S atom.However, the effect was relatively small (ca. 10-14 mV).E011 was 1.72 +/- 0.02 V for β-mercaptoethanol.The corresponding potentials for the cyclic anions of dithiothreitol, dithioerythritol, and lipoamide were the same within experimental error, but the uncertainties were larger (+/- 0.04 V).For the reaction e- + -S-S- = -S-S-- (22), the magnitude of E022 was calculated to be -1.60 V, showing that only strongly reducing species could donate electrons to disulfide.Rate constants for several of the forward and backward reactions in the equilibria were also determined.
- Surdhar, Parminder S.,Armstrong, David A.
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Read Online
- Green method for synthesizing high value-added mercaptoacid by catalyzing addition reaction of H2S and olefine acid by using ionic liquid as catalyst
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The invention relates to a green method integrating catalysis, reaction and separation, which is used for producing beta-mercapto carboxylic acid through addition of alpha, beta-unsaturated carboxylic acid and H2S by taking amino-functionalized hydrophobic ionic liquid as a catalyst. H2S is activated through tertiary amine alkaline sites contained in the ionic liquid, so that H2S and double bonds of alpha, beta-unsaturated carboxylic acid are subjected to an addition reaction, and recycling of H2S is realized. The product obtained after the reaction can be subjected to water phase liquid-liquid extraction to realize separation of the catalyst and the product, and the ionic liquid can be recycled. In the system, the ionic liquid is both a catalytic medium and a reaction medium, no other organic solvent participates in the system, H2S is efficiently utilized, meanwhile, high-added-value products such as mercapto acid are obtained, and the method is more economical and environmentally friendly and conforms to the development concept of green chemical industry.
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Paragraph 0041; 0049-0050; 0053-0054
(2021/05/05)
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- Method for synthesizing 3-mercaptopropionic acid from acidic waste gas
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The invention relates to the technical field of sulfhydryl compound synthesis, and in particular, relates to a method for synthesizing 3-mercaptopropionic acid from acid waste gas. The method comprises the steps: firstly, purifying hydrogen sulfide in the acidic waste gas by a pressure swing adsorption method; secondly, synthesizing 3-mercaptopropionic acid: step 1, selecting materials; step 2, carrying out a first-step reaction; step 3, carrying out a second-step reaction; and step 4, carrying out a third-step reaction. According to the method for synthesizing the 3-mercaptopropionic acid from the acid waste gas, hydrogen sulfide in the acid waste gas discharged from an oil refinery is adopted, waste is turned into wealth, reasonable utilization of resources is taken as guidance, and the3-mercaptopropionic acid is synthesized with a low-cost and less-'three wastes' method. According to the method, acrylic acid and the hydrogen sulfide product obtained in the first step are used as raw materials, triethylamine is used as a catalyst, and dimethylacetamide is used as a solvent, so that the reaction conversion rate is high, the yield is high, byproducts are reduced, the traditional process route is broken through, the problem of three wastes caused by acidification and extraction is avoided, and the method is an excellent synthesis and post-treatment route.
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Paragraph 0027; 0031-0035; 0037; 0041-0047; 0051-0055; 0057
(2020/05/01)
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- Method for preparing mercaptocarboxylic acid or derivatives thereof by aminolysis of thioureidocarboxylic acid or derivatives thereof
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The invention relates to a method for preparing mercaptocarboxylic acid or derivatives thereof by aminolysis of thioureidocarboxylic acid or derivatives thereof. The method mainly comprises the following steps: 1, dissolving thioureidocarboxylic acid or a derivative thereof in ammonia water or a mixed solution of ammonia water and a cosolvent, heating the system to 40-150 DEG C, and reacting for long time until reaction of the thioureido salt is finished; 2, cooling the reaction system, neutralizing the reaction system by using acid, removing the solvent by using a solvent extraction system, and separating to obtain the mercaptocarboxylic acid or the derivative thereof; and 3, concentrating and filtering the residual water phase or organic phase, recycling the distilled water phase or organic phase, and taking the solid ammonium salt mixture as a nitrogen fertilizer. According to the method, the defects that pollutants are complex and difficult to treat, and the environment is pollutedin the prior art that metal ions such as NaOH are adopted for alkaline hydrolysis of thioureidocarboxylic acid and derivatives thereof to prepare mercaptocarboxylic acid and derivatives thereof are overcome. The method has the advantages of simple process, low cost, no environmental pollution and the like, and can basically realize zero emission of three wastes.
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Paragraph 0008
(2020/06/09)
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- Thiourea derivative and thiohydracrylic acid parallel production method
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The invention belongs to the technical field of organic synthesis and particularly discloses a thiourea derivative and thiohydracrylic acid parallel production method. The thiourea derivative and thiohydracrylic acid parallel production method comprises neutralizing and aminolyzing S-acrylic-dithiocarbamate in aqueous or organic solvent to obtain thiourea derivatives and the by-product of 3-mercapto propionate, wherein the 3-mercapto propionate is acidized into 3-mercapto propionic acid. The thiourea derivative and thiohydracrylic acid parallel production method provides a practical method forsynthesis of the thiourea derivatives and the 3-mercapto propionic acid and has the advantages of being mild in reaction, short in reaction time, simple in technical process and high in yield of thethiourea derivatives and the 3-mercapto propionic acid, thereby achieving certain industrial economic values.
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Paragraph 0053; 0054
(2019/03/25)
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- Preparation method of 3-mercaptopropionic acid
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The embodiment of the invention relates to the field of synthesis of sulfhydryl compounds, in particular to a preparation method of 3-mercaptopropionic acid. The preparation method includes the stepsthat sodium acrylate and sodium bisulfide or sodium sulfide are mixed and have a reaction; the sodium sulfide is added (or the sodium sulfide and powdered sulfur are added), and the reaction is continued; crystallization and acidification by adding acid are conducted, and a 3-mercaptopropionic acid solution is obtained. According to the preparation method, the costs of raw materials are low, the yield of the 3-mercaptopropionic is high, the purity of the 3-mercaptopropionic is high, solid waste and a solvent can be separated and recycled, a sodium salt is used as an industrial product after crystallization, the solvent is distilled, recycled and reused, and three wastes are easy to process.
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Paragraph 0053-0064
(2019/11/13)
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- Preparation method of beta-sulfhydryl carboxylic acid compound
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The invention provides a preparation method of a beta-sulfhydryl carboxylic acid compound. A solid base catalyst used in the method has suitable alkali strength, so that not only is hydrogen sulfide enabled to be activated and a reaction promoted to be carried out, but the binding between carboxyl groups and active sites in raw materials or products is also inhibited, and the active sites are prevented from being deactivated slowly. Furthermore, the solid base catalyst selects a polyhydroxy compound as a carrier, and a great deal of hydroxyl groups on the surface of the carrier can promote thehydrogen sulfide to be dissolved in a reaction system and adsorbed on the surface of the catalyst so as to enable the hydrogen sulfide to be migrated to the positions around the active sites for being activated, so that the high conversion rate and high selectivity of the reaction also can be enabled to be reached at the lower pressure, and the catalytic stability is better. In addition, the preparation method is mild in reaction conditions, and the gas-liquid phase reaction is carried out under the conditions of low temperature and low pressure, so that the method is easily applied to industry. Experiments prove that the reaction conversion rate and selectivity of the beta-sulfhydryl carboxylic acid compound prepared by the method are respectively not less than 98% and 88%. After the compound is continuously evaluated for 100h, the catalytic stability of the compound is proved to be better.
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Paragraph 0068; 0073; 0074; 0080; 0082
(2018/06/26)
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- Microchannel reactor-based cyano hydrolysis reaction method
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The invention discloses a microchannel reactor-based cyano compound hydrolysis reaction method, and particularly, a compound comprising a cyano group in the molecule has the cyano hydrolysis reactionby using a microchannel reactor under the action of alkaline or acid-alkaline substances. By using the microchannel reactor in the process, the raw material is instantaneously evenly mixed and efficiently transfers heat; the most important danger of rushing of the material in the production process, caused by hydrolysis of the cyano compound through the alkali, is avoided; meanwhile, the equivalence ratio of the raw material in the reaction process is also reduced; the side reaction is reduced; the reaction time is shortened to dozens of minutes or even dozens of seconds. In a word, the process improves the operation safety of the reaction, the safe enlarged production of the cyano compound is realized, the time for the hydrolysis reaction of the cyano compound is shortened, the reaction selectivity and the reaction efficiency are improved, the energy consumption of the production is reduced, the use ratio of the raw material is increased, the production process is more environmentallyfriendly, the production cost is low, meanwhile, the used equipment occupies a small area, the production capacity of the equipment is high, and the production efficiency and the production capacityare greatly improved.
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Paragraph 0049-0058
(2018/08/04)
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- METHOD FOR PRODUCING 3-MERCAPTOPROPIONIC ACID, AND METHODS USING SAME FOR PRODUCING CARBOXYLIC ACID ESTER COMPOUND HAVING MERCAPTO GROUP AND THIOURETHANE-BASED OPTICAL MATERIAL
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A method for producing 3-mercaptopropionic acid and methods using same for producing a carbonic acid ester compound having a mercapto group and a thiourethane-based optical material. The present invention improves a process during the production of 3-mercaptopropionic acid, significantly increases yield, and reduces the temperature and time during vacuum distillation, thereby preventing the destruction of a product and significantly increasing productivity. The present invention allows high-purity 3-mercaptopropionic acid having an excellent color to be finally yielded; accordingly, by using same, a high-purity carbonic acid ester compound having an excellent color and a mercapto group can be inexpensively obtained. A thiourethane-based polymeric composition and a thiourethane-based optical material obtained by polymerizing same can likewise be inexpensively obtained by using said carbonic acid ester compound. Such carbonic acid ester compound can be used for the production of inexpensive thiourethane optical lenses; consequently, inexpensive optical lenses having an excellent color can be obtained.
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Paragraph 0051-0052
(2018/07/15)
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- Preparation method of sulfhydryl compound
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The invention belongs to the technical field of preparation of sulfur-containing compounds, and relates to a preparation method of a sulfhydryl compound. The sulfhydryl compound is prepared through taking an acrylic acid type compound as a raw material and taking a high-polarity compound as a solvent and introducing H2S gas to react under normal pressure in the presence of a catalyst and an auxiliary agent. The preparation method of the sulfhydryl compound has the advantages of moderate reaction conditions, rapid reaction speed, high conversion ratio and high selectivity, and industrial application is easy to realize.
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Paragraph 0029; 0030; 0031; 0032; 0035; 0036; 0039; 0040
(2017/08/27)
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- Method for producing high-purity 3-thiohydracrylic acid
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The invention discloses a method for producing high-purity 3-thiohydracrylic acid. The method comprises the following steps that 1, an addition reaction is carried out, wherein acrylonitrile and sodium bisulfide are added to generate 3-mercapto propionic nitrile and sodium sulphide, sodium sulphide can react with acrylonitrile to generate disulfide generation malononitrile, and therefore an addition product is a mixture of 3-mercapto propionic nitrile and disulfide generation malononitrile; 2, a hydrolysis reaction is carried out, wherein in a hydrochloric acid system, the mixture of 3-mercapto propionic nitrile and disulfide generation malononitrile is hydrolyzed into a mixture of 3-thiohydracrylic acid and dithio malonic acid; 3, a reduction reaction is carried out, wherein in the hydrochloric acid system, dithio malonic acid is reduced into 3-thiohydracrylic acid through iron powder, and crude 3-thiohydracrylic acid is obtained after solvent extraction and solvent recovery; 4, a refining procedure is carried out, wherein crude 3-thiohydracrylic acid is rectified to obtain finished 3-thiohydracrylic acid. The defects in the prior art are overcome, the advantages of being low in cost and high in yield are achieved, all the reaction procedures are carried out under normal pressure, three wastes are reutilized, and almost no three wastes are discharged.
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Paragraph 0031; 0032; 0033; 0034; 0035
(2016/10/08)
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- Unusual multistep reaction of C70Cl10 with thiols producing C70[SR]5H
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We report a reaction of the chlorofullerene C70Cl10 with thiols producing C70[SR]5H with all organic addends attached around one central pentagon at the pole of the C70 cage. This reaction was shown to proceed via a complicated radical pathway, presumably involving addition, substitution, rearrangement, and/or elimination steps. The obtained C70[SR]5H products were shown to be very unstable and undergo quantitative decomposition to pristine C70, RSSR, and RSH at elevated temperatures (e.g., 50 °C). Quantum chemical calculations and NMR spectroscopy data showed that cleavage of organic addends from the fullerene cage could be induced by solvation effects in solution.
- Khakina, Ekaterina A.,Peregudov, Alexander S.,Yurkova, Anastasiya A.,Piven, Natalya P.,Shestakov, Alexander F.,Troshin, Pavel A.
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p. 1215 - 1219
(2016/03/01)
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- Beta-mercaptopropionic acid synthetic method
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The invention provides a beta-mercaptopropionic acid synthetic method. The method takes acrylamide and hydrogen sulfide or sodium sulfhydrate as raw materials to obtain the addition products through an addition reaction, caustic soda liquid is employed for hydrolyzing the addition products, and acidifying the addition products to obtain the beta-mercaptopropionic acid; the reaction activity of acrylamide is similar with acrylonitrile, when addition is carried out with hydrogen sulfide or sodium sulfhydrate, the yield is high, and the by-product is little. During hydrolysis and acidifying processes, three wastes can be ideally recovered, the three wastes are conversed to the industrial byproduct for sale, economic benefit is provided to the enterprise, and the synthesis route of the beta-mercaptopropionic acid has the advantages of high yield, good purity, less three wastes, easy processing of waste water, and is a better synthesis route.
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Paragraph 0036; 0037; 0041; 0042
(2017/02/02)
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- Production method of 3-mercaptopropionic acid
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The invention belongs to the field of a chemical synthesis technology, and concretely relates to a production method of 3-mercaptopropionic acid. The production method of the 3-mercaptopropionic acid comprises the following steps: a 30% NaHS solution, NaOH and sulfur powder are used as raw materials, temperature is heated to 45 DEG C and a heat reaction is carried out, and a reaction solution is standby; acrylonitrile is added dropwisely into the reaction solution, the temperature of the system is controlled at 40-45 DEG C, a reaction is carried out at 45-50 DEG C after the adding in a dropwise manner is finished, and a reaction mother liquor is obtained. The reaction mother liquor is added dropwisely into 31% hydrochloric acid, and the adding in a dropwise manner is finished within 2-4 hours. After the adding in a dropwise manner is finished, a reflux reaction at 118-120 DEG C is carried out for 6-12 hours, iron powder is added for carrying out a reduction reaction, a solvent extraction treatment is carried out after the reduction reaction finishes, dichloroethane is recovered for indiscriminate application, and a high-content 3-mercaptopropionic acid finished product is obtained by rectification in a high vacuum condition. The 3-mercaptopropionic acid prepared by the production method has a content which is higher or equal to 99.5%, the overall yield of the 3-mercaptopropionic acid is higher or equal to 96%.
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Paragraph 0016-0020
(2017/01/23)
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- Continuous stable production technology of mercaptopropionic acid
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The invention relates to continuous stable production technology of mercaptopropionic acid, and aims to provide production technology continuous and stable in operation, high in extraction efficiency, low in energy consumption and cost, and suitable for industrialization of mercaptopropionic acid. Acrylonitrile and sodium hydrosulfide are subjected to an addition reaction and hydrolysis with acid addition; the obtained hydrolysate is subjected to reduction with iron powder added to obtain a reduced hydrolysate; the reduced hydrolysate undergoes temperature reduction, filtration and impurity removal; and the reduced hydrolysate obtained from impurity removal is sent to extraction equipment for extraction to obtain a mercaptopropionic acid product. The technology is stable in operation and low in production cost, and the mercaptopropionic acid product is high in purity.
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Paragraph 0017; 0018
(2017/01/26)
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- Quantitative Reactivity Scales for Dynamic Covalent and Systems Chemistry
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Dynamic covalent chemistry (DCC) has become a powerful tool for the creation of molecular assemblies and complex systems in chemistry and materials science. Herein we developed for the first time quantitative reactivity scales capable of correlation and prediction of the equilibrium of dynamic covalent reactions (DCRs). The reference reactions are based upon universal DCRs between imines, one of the most utilized structural motifs in DCC, and a series of O-, N-, and S- mononucleophiles. Aromatic imines derived from pyridine-2-carboxyaldehyde exhibit capability for controlling the equilibrium through distinct substituent effects. Electron-donating groups (EDGs) stabilize the imine through quinoidal resonance, while electron-withdrawing groups (EWGs) stabilize the adduct by enhancing intramolecular hydrogen bonding, resulting in curvature in Hammett analysis. Notably, unique nonlinearity induced by both EDGs and EWGs emerged in Hammett plot when cyclic secondary amines were used. This is the first time such a behavior is observed in a thermodynamically controlled system, to the best of our knowledge. Unified quantitative reactivity scales were proposed for DCC and defined by the correlation log K = SN (RN + RE). Nucleophilicity parameters (RN and SN) and electrophilicity parameters (RE) were then developed from DCRs discovered. Furthermore, the predictive power of those parameters was verified by successful correlation of other DCRs, validating our reactivity scales as a general and useful tool for the evaluation and modeling of DCRs. The reactivity parameters proposed here should be complementary to well-established kinetics based parameters and find applications in many aspects, such as DCR discovery, bioconjugation, and catalysis.
- Zhou, Yuntao,Li, Lijie,Ye, Hebo,Zhang, Ling,You, Lei
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supporting information
p. 381 - 389
(2016/01/26)
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- METHOD FOR PRODUCING 3-MERCAPTOPROPIONIC ACID USING REACTIVE DISTILLATION
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In the present invention, provided is a method for manufacturing 3-mercaptopropionic acid where the provided method has simple processes with good reactive efficiency and accordingly mass-produces 3-mercaptopropionic acid.COPYRIGHT KIPO 2015
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Paragraph 0052-0056
(2016/12/22)
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- METHOD FOR PRODUCING BETA-MERCAPTOCARBOXYLIC ACID
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A process for preparing β-mercaptocarboxylic acid of the present invention is provided with Step a for reacting a compound represented by a formula: X12S (X1 represents hydrogen, Na or K) or a compound represented by a formula: X2SH (X2 represents Na or K), alkali hydroxide represented by a formula: X3OH (X3 represents Na or K), and unsaturated carboxylic acid represented by the following General Formula (1) to obtain a reaction solution including a compound represented by the following General Formula (2) and a compound represented by the following General Formula (3), Step b for neutralizing the reaction solution obtained in Step a with an acid to obtain a reaction solution including β-mercaptocarboxylic acid represented by the following General Formula (4) and a compound represented by the following General Formula (5), Step c for distillation-refining the reaction solution obtained in Step b to obtain the β-mercaptocarboxylic acid represented by General Formula (4), and Step d for returning a distillation residue including the compound represented by General Formula (5) in Step c to Step a.
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Paragraph 0114; 0115; 0116; 0117; 0118; 0119
(2014/10/15)
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- PROCESS FOR PREPARING ?-MERCAPTOCARBOXYLIC ACID
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There is provided a process for preparing β-mercaptocarboxylic acid represented by the following General Formula (3) comprising step of reacting hydrogen sulfide, alkali hydroxide represented by a formula: XOH (X represents Na or K), and unsaturated carboxylic acid represented by the following General Formula (1) under atmospheric pressure to obtain a reaction solution including a compound represented by the following General Formula (2) and step of neutralizing the reaction solution in an acid. An amount of the alkali hydroxide is equal to or greater than total moles of the unsaturated carboxylic acid and the hydrogen sulfide.
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Paragraph 0091-0095
(2014/09/30)
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- TUNABLE FLUORESCENCE USING CLEAVABLE LINKERS
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The invention relates to cleavable chemistry in general, and in particular, to tunable fluoresence using cleavable linkers present in fluorochrome-quencher conjugates.
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Paragraph 00116-00117
(2014/11/11)
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- Cysteine as a sustainable sulfur reagent for the protecting-group-free synthesis of sulfur-containing amino acids: Biomimetic synthesis of l-ergothioneine in water
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Biomass-derived cysteine was used as a sustainable sulfur source for the synthesis of rare sulfur-containing amino acids, such as l-ergothioneine (4), which might be a new vitamin, and various l- or d-2-thiohistidine compounds. Key in this simple, one-pot two-step procedure in water is a bromine-induced regioselective introduction of cysteine followed by a novel thermal cleavage reaction in the presence of thiols, a safer alternative to hazardous red phosphorus. Besides avoiding hazardous sulfur reagents, the new protecting-group-free approach reduces drastically the total number of steps, compared to described procedures. The main drawback, i.e. handling of liquid bromine as an activating and oxidizing reagent in water, was addressed by evaluating four alternative methods using in situ generation of bromine or HOBr, and first encouraging results are described.
- Erdelmeier, Irene,Daunay, Sylvain,Lebel, Remi,Farescour, Laurence,Yadan, Jean-Claude
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experimental part
p. 2256 - 2265
(2012/09/08)
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- SN2-type nucleophilic opening of β-thiolactones (thietan-2-ones) as a source of thioacids for coupling reactions
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β-Thiolactones monosubstituted in the 3-position by alkyl and carbamoyl groups undergo nucleophilic ring opening by arenethiolates through a process involving an SN2-type attack at the 4-position leading to 3-arylthiopropionates substituted in the 2-position. These thiocarboxylates can be trapped in situ by Mukaiyama's reagent or Sanger's reagent through a nucleophilic aromatic substitution process leading to highly activated thioesters that are then allowed to react further with primary or secondary amines leading, overall, to one-pot, three-component syntheses of 3-arylthiopropionamides carrying various substituents in the 2-position. Alternatively, the trapping combination of an electron deficient aryl halide and an amine may be replaced by a 2,4-dinitrobenzenesulfonamide, resulting in the formation of the same products overall with the incorporation of the latent amine in the sulfonamide into the final amide product. In another embodiment, the thiocarboxylate intermediate is allowed to react with a sulfonyl azide, resulting overall in N-arenesulfonyl 3-arylthiopropionamide derivatives.
- Crich, David,Sana, Kasinath
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scheme or table
p. 3389 - 3393
(2009/10/02)
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- METHOD OF PRODUCING β-MERCAPTOCARBOXYLIC ACIDS
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The invention relates to a method for efficiently producing β-mercaptocarboxylic acids using a solid acid catalyst such as zeolite, which product corresponds to respective starting materials selected from α, β-unsaturated carboxylic acids (α, β-unsaturated carboxylic acid, a, β-unsaturated carboxylic acid ester, ex, β-unsaturated amide, a, β-unsaturated aldehide and α, β-unsaturated ketone) and hydrogen sulfides (hydrogen sulfide, sulfide salt and hydrosulfide salt), wherein a solvent compatible with water is used in the reaction. According to the invention, β-mercaptocarboxylic acids which are useful as additives in synthetic materials for pharmaceutical or agricultural agents and in polymer compounds can be industrially produced efficiently by using easily available a, β-unsaturated carboxylic acid (such as crotonic acid) at high yield.
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Page/Page column 31-32
(2009/04/25)
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- Process for the manufacture of mercaptocarboxylic acids from unsaturated carboxylic acids
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A mercaptocarboxylic acid of formula (I) is prepared by reacting an unsaturated carboxylic acid of formula (II) with a hydrosulphide of formula ASH, A being an alkali metal cation or a cation NR3R4R5R6+, R3to R6each representing H or a hydrocarbon radical, or of formula Q(SH)2, Q being an alkaline-earth metal cation, by acidifying the resulting reaction medium in order to obtain the desired compound (I). According to the present invention, the reaction is carried out with a supply of H2S other than that supplied by the neutralization of the acid (II). In particular, H2S is introduced into the medium by a direct external supply. H2S can also be produced in situ by reacting the hydrosulphide with at least one acid introduced into the medium. The compound (I) is obtained with a very good selectivity.
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Page column 6; 7
(2008/06/13)
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- S-4-Methoxytrityl mercapto acids: Synthesis and application
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4-Methoxytrityl (Mmt)-mercapto acids were obtained either by the reaction of mercapto acids with Mmt-chloride or by the reaction of halo acids with Mmt-thiol. The derivatives obtained were used in the solid-phase synthesis of small libraries of mercaptoacylamino acids and mercaptoacyl peptides. The removal of the Mmt-group was performed by treatment with trifluoroacetic acid (TFA) in dichloromethane (DCM) using triethylsilane (TES) as scavenger.
- Mourtas, Spyros,Gatos, Dimitrios,Kalaitzi, Vagiani,Katakalou, Christina,Barlos, Kleomenis
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p. 6965 - 6967
(2007/10/03)
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- Equilibrium and kinetics studies of transnitrosation between S-nitrosothiols and thiols
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Using UV-vis spectrometrical measurements, equilibrium constants for NO transfer between S-nitroso-N-acetyl-penicillamine (SNAP) and different thiols as well as kinetic data for NO transfer from S-nitroso bovine serum albumin (BSANO) to thiols have been obtained. NO transfer from SNAP to other primary/secondary thiols are thermodynamically favorable, whereas other S-nitrosothiols exhibit similar NO transfer potential. The obtained Gibbs free energy, enthalpy and entropy data indicated that NO transfer reactions from SNAP to four thiols are exothermic with entropy loss. The kinetic behavior of BSANO/RSH transfer can be related to both the acidity of sulfhydryl group and the electronic structure in thiol.
- Wang, Kun,Wen, Zhong,Zhang, Wei,Xian, Ming,Cheng, Jin-Pei,Wang, Peng George
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p. 433 - 436
(2007/10/03)
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- 2,3-disubstituted cyclopentanone derivatives, process for producing the same, and medicinal use thereof
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The present invention relates to a compound represented by the following general formula (1) STR1 (wherein X represents O, S, SO, SO2, or NH, Y is a substituted or unsubstituted hydrocarbon residue containing 1 through 6 carbon atoms and having an overall molecular weight of not less than 15 and not more than 400, and the hydrocarbon residue, when the residue is ring, may contain one or two hetero-atoms in the ring, and Z is a carboxyl group, a group derived therefrom or an aliphatic hydrocarbon residue having from 1 to 4 carbon atoms which may be substituted or unsabstituted) or a pharmacologically acceptable salt thereof (excluding (1R,2S)-2-[(2R)-(2-acetyl-amino-2-carboxyethyl)thiomethyl]-3-oxo-1-cyclopentane-carboxylic acid (cystacyclin)), a method for production thereof and a medicinal use thereof. The compound of the present invention is useful as a neuron differentiation accelerator.
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- Downfield chemical shifts at α-protons and carbons of β-propiothiolactones
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Both the α-protons and carbons of β-propiothiolactones exhibit atypical downfield chemical shifts. The α-protons of β-propiothiolactones with no heteroatom at the α-position appear at 3.53-5.35ppm, whereas the α-carbons appear at 56.9-86.2 ppm. The major cause of the unexpected deshielding effect was rationalized by assuming a through-space interaction between the occupied orbital of the α-carbon and the vacant orbital of sulfur. Copyright
- Lee, Hee Bong,Park, Hyung-Yeon,Lee, Bon-Su,Kim, Young Gyu
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p. 468 - 471
(2007/10/03)
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- A general and mild synthesis of thioesters and thiols from halides
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The conversion of a wide variety of halides to thioesters by reaction with potassium thiocetate under mild conditions is described, and the generality of the method is demonstrated.
- Zheng, Tu-Cai,Burkart, Maureen,Richardson, David E.
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p. 603 - 606
(2007/10/03)
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- Effect of the α-methyl substituent on chemoselectivity in esterase-catalyzed hydrolysis of S-acetyl sulfanylalkanoates
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(Equation Presented) The isomeric compounds 1 and 3, which differ only in the position of a methyl substituent, give opposite chemoselectivities in an esterase-catalyzed hydrolysis reaction. The esterase was chemoselective for the oxoester in 1, but for the thiol ester group in 3. A high enantioselectivity was observed for both 1 and 3.
- Kumar, Ish,Jolly, Ravinder S.
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p. 207 - 209
(2008/02/11)
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- Triphendioxazine dyestuffs
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The novel triphendioxazine dyestuffs of the formula STR1 in which the substituents R, R', T1, T2, X, Y and n have the meanings given in the description are highly suitable for the dyeing and printing of cellulose-containing or amido-containing material.
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- Method for making β-mercaptopropionic acid
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A novel method for making β-mercaptopropionic acid which comprises adding alkaline hydroxide to thiodipropionic acid to obtain alkaline thiodipropionate, mixing thus obtained alkaline thiodipropionate with an aqueous solution of alkaline sulfide, then reacting the mixed solution with addition of heating in a required time, and acidifying the reacted solution with a strong acid.
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- Carboxy containing monomers
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Certain ethylenically unsaturated polymerizable monomers having a reactive carboxy group are useful for preparing homo- and copolymers for a variety of uses, including diagnostic assays. The polymers can be supplied as latex particles in aqueous compositions. The monomers are represented by the structure: STR1 wherein: R is hydrogen, halo or alkyl of 1 to 3 carbon atoms, M is hydrogen, an alkali metal ion or an ammonium ion, and L is a linking group having from 8 to 50 atoms in its linking chain, and comprises two or more divalent hydrocarbon groups connected or terminated with one or more nitrogen, oxygen or sulfur atoms, or with one or more groups containing such atoms in the linking chain, provided L has at least one arylene which is not directly connected to the terminal STR2 group, and further provided that none of the hydrocarbon groups has non-aromatic unsaturation.
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- Pyrrolo (1,2-A) thieno (2,3-F) (1,4)-diazepines
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Novel 4H-pyrrolo[1,2-a]thieno[2,3-f][1,4]diazepine which are usable as a medicinal product and correspond to the general formula (I): STR1 in which: R 1, R 2, R 3 and R 4 have the same meaning as given in the specification.These compounds, as well as their physiologically tolerable salts, may be used in therapy, in particular in the treatment of disorders linked to hypoxemia and to certain metabolic disorders.
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- Kinetics and Equilibria of Thiol/Disulfide Interchange Reactions of Selected Biological Thiols and Related Molecules with Oxidized Glutathione
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Rate constants for reaction of coenzyme A and cysteine with oxidized glutathione (GSSG) and equilibrium constants for the reaction of coenzyme A, cysteine, homocysteine, cysteamine, and related thiols with GSSG by thiol/disulfide interchange were determined over a range of pD values by NMR spectroscopy.The rate constants for reaction of the thiolate anion forms of coenzyme A and cysteine with GSSG suggest that reduction of GSSG by coenzyme A and cysteine is a mechanistically uncomplicated SN2 reaction.Equilibrium constants for the thiol/disulfide interchange reactions show a strong dependence on the Bronsted basicity of the thiolate anion.In a similar way, ΔE0', the difference between the half-cell potentials for the RSSR/RSH and GSSG/GSH redox couples, is linearly dependent on the difference between the pKA values of RSH and glutathione: ΔE0' = 64ΔpKA - 7.7 where ΔE0' is in units of mV.The reducing strength at a given pH is also determined by the fraction of the thiol present in the reactive thiolate form.At pD 7, the half-cell potentials for coenzyme A, cysteine, homocysteine, and cysteamine are close to that of glutathione, the major intracellular thiol redox system, which suggests that small changes in the intracellular redox potential can cause significant changes in the intracellular distribution of these biological thiols between their reduced and oxidized forms.
- Keire, David A.,Strauss, Erin,Guo, Wei,Noszal, Bela,Rabenstein, Dallas L.
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p. 123 - 127
(2007/10/02)
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- Tumor-resolving and histolytic medicaments and their use
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Dehydrooligopeptides, some of which are known, demonstrate histolytic and tumor-resolving activity and may be used in medicaments causing the lysis of animal tissues and/or tumors in warm-blooded animals.
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- Azole derivatives
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Azole derivatives of the formula SPC1 Wherein R1 is free or esterified carboxyl or other functionally modified carboxyl group, R2 and R3 each are aryl; A is Cn H2n in which n is an integer from 1 to 10, inclusive; and Z is O or S; and the physiologically acceptable salts thereof, possess, with good compatibility, excellent antiphlogistic activity and, in particular, influence favorably the chronic progressive diseases of the joints, e.g., arthritis. They can be prepared from compounds of the formula SPC2 Wherein X1 is a group convertible into the group --S--A--R1, and R2 and R3 have the values given above.
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