- Kinetics of the Aqueous Periodate Oxidation of Aliphatic Disulfides and Thioethers
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Water-soluble aliphatic disulfides are oxidatively cleaved by borate-buffered periodate at 23 deg C.The reaction conditions were selected because they are used for the oxidation of methionine in protein modification, and we wanted to test the reactivity of the disulfide linkage in various bifunctional molecules under these conditions.A colorimetric method was developed which uses 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) to determine the concentrations of periodate.The γ-substituted amine-disulfide 1b consumes 4 equiv of periodate at a rate which is accelerated 100-fold over that of 4,4'-dithiodibutanol (1c) and forms the cyclic sulfinamide 3 an sulfonamide 4.To account for the stoichiometry and acceleration, we have proposed intermediates in which a nucleophilic sulfur atom attacks an oxygen atom of periodate to give an anhydride or complex rather than invoking direct oxygen atom transfer.The γ- and δ-hydroxy disulfides 1a and 1c consume 5 equiv of periodate and are oxidized to the sulfonic acids.The rate of DL-methionine (2a) oxidation in water is reported, along with the oxidations of dibutyl sulfide (2c) and of 1,5-dithiacyclooctane (2d) in 50percent aqueous ethanol.The oxidation of 2d is only 2.1 times faster than the oxidation of 2c, showing that the transannular sulfur atom in 2d does not participate in the oxidation.A comparison of the rate of periodate oxidation of disulfides, thioethers, and ethylene glycol under the same conditions shows that it is possible for these processes to be competitive.
- Evans, Brian J.,Takahashi Doi, Joyce,Musker, W. Kenneth
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- Solvent-free method for preparing 1,3-propane sultone
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The invention discloses a solvent-free method for preparing 11,3-propane sultone. According to the method, propenol and ammonium sulfite are used as reaction raw materials; and deionized water is adopted as medium. The preparation method comprises the following steps: stirring ammonium sulfate and deionized water; at 20-50 DEG C, preparing a mixed solution from acrolein, an initiator and deionizedwater, dropwise adding the mixed solution into a beaker, and carrying out catalytic reaction to generate an aqueous solution of 3-hydroxypropylammonium sulfonate; adding calcium hydroxide to carry out alkalization reaction, after alkalization is completed, adding concentrated sulfuric acid for acidification treatment to obtain 3-hydroxypropanesulfonic acid and solid calcium sulfate, and performing filtration to obtain an aqueous solution of the 3-hydroxypropanesulfonic acid; carrying out concentration and reduced pressure rectification to obtain a target product; adding a certain amount of calcium hydroxide and water into kettle residues, performing hydrolysis to obtain an aqueous solution of calcium 3-hydroxypropanesulfonate, adding concentrated sulfuric acid for acidification treatment,performing filtration to obtain an aqueous solution of 3-hydroxypropanesulfonic acid, and carrying out concentration and reduced pressure rectification to obtain the target product. The method has the advantages of simple process, simple raw materials, no solvent and no waste, and the yield can reach 95%.
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Paragraph 0009; 0023-0028
(2019/12/02)
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- 1,3-propane sultone preparation method
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The invention relates to a 1,3-propane sultone preparation method, which comprises: S1, completely mixing in a reaction container by using 3-chloropropanol and sodium sulfite as raw materials and using water as a solvent, controlling the temperature at 25-120 DEG C, carrying out a reaction for 4-48 h, carrying out pressure reducing dewatering concentration, adding concentrated hydrochloric acid tothe concentrated liquid, carrying out acidification, controlling the temperature at 0-80 DEG C, stirring for 1-24 h, filtering, and concentrating the filtrate to obtain 3-hydroxypropanesulfonic acid;S2, controlling the temperature of the concentrated liquid obtained in the step S1 at 40-110 DEG C, and carrying out pressure reducing concentrating to carry out dewatering ring closure on the 3-hydroxypropanesulfonic acid in the concentrated liquid to obtain a crude product containing 1,3-propane sultone; and S3, rectifying the crude product containing 1,3-propane sultone to obtain 1,3-propane sultone. According to the present invention, the method has characteristics of short process route, less three-waste and simple post-treatment, wherein the total yield can achieve more than 90%, and the purity of the product can achieve more than 99.9%.
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Paragraph 0033-0035; 0038-0040; 0043-0045; 0049
(2019/10/01)
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- A method for preparing 1, 3 - propane lactone (by machine translation)
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The invention discloses a 1, 3 - propane lactone of the preparation method, comprises the following steps: first preparing a calcium chloride solution, then adding citric acid mixed solution prepared A, and mixed with the sodium polyacrylate solution preparing mixed solution B, then rapidly added to the sodium carbonate solution precipitation, for preparing porous calcium carbonate, and peroxy benzoic acid in the solution is impregnated to obtain the catalyst; the allyl sodium sulfonate and sulfuric acid solution, adding catalyst to react, adding ethanol solution of sodium hydroxide reaction, and finally adding hydrochloric acid, to obtain 3 - hydroxy propane sulfonic acid; the obtained 3 - hydroxy propane sulfonic acid and hexane mixed in added to the three-mouth flask, stirring the reaction, after the reaction cooled to the room temperature, vacuum distillation, to obtain the target product 1, 3 - propane lactone. The method is simple in operation, low energy consumption, high product yield. (by machine translation)
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Paragraph 0026-0032; 0034-0040; 0042-0048; 0050-0056
(2019/01/08)
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- Method for preparing 1,3-propane sultone
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The invention discloses a method for preparing 1,3-propane sultone. The method includes the steps that (1) 1,3-propanesulfonic acid is prepared: sodium sulfite, sodium bisulfite and allyl alcohol are added into a reactor under the room temperature condition, a pH value is regulated to be 5 to 5.5, infrared radiation induction is adopted, azo diisobutyl nitrile performs catalytic reaction for 2 to 3 hours, concentrated hydrochloric acid is added, the reaction is performed at the temperature of 85 to 90 DEG C for 2 to 3 hours, generated salt is removed through filtration, and n-butyl alcohol is added into filtrate to perform extraction separation so as to obtain the 3-hydroxy-1-propanesulfonic acid; (2) the 1,3-propane sultone is prepared: pyridinium p-toluenesulfonate and zeolites are added, dehydration reaction is performed at the temperature of 50-60 DEG C for 2-3 hours, distillation is performed to obtain 147-149 DEG C of fraction, and calcium oxide is added to perform heating reflux for 1-2 hours to obtain the 1,3-propane sultone. The product prepared by means of the method is high in yield and purity. In addition, the moisture content of the product is mostly above 0.1%, the amplification effect and other problems do not exist, and the method is suitable for industrial production.
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Paragraph 0039; 0041
(2016/10/07)
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- 1. 3 - propane sulfonic acid lactone preparation method (by machine translation)
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The invention discloses 1, 3 - propane sultone preparation method, steps are as follows: (1) to the catalyst and sodium bisulfite as raw materials, deionized water as the medium, in the initiator catalytic addition react to generate the 3 - hydroxy c sodium sulfonate; (2) adding sulfuric acid to the reaction solution in the acidification, then distilled to remove the excessive water, adding anhydrous ethanol extraction and filtration, to obtain 3 - hydroxy propane sulfonic acid ethanol solution; (3) the 3 - hydroxy propane sulfonic acid ethanol solution of the first normal pressure distillation to remove the ethanol, and get the 1, 3 - propane sulfonic acid lactone; (4) is added to the distillation still in the sodium hydroxide aqueous solution to perform hydrolysis, then adding sulfuric acid acidified, then adding anhydrous ethanol extraction and filtration, to obtain 3 - hydroxy propane sulfonic acid ethanol solution, then remove ethanol from atmospheric distillation, and get the 1, 3 - propane sulfonic acid lactone. The above preparation method can reduce the reaction temperature, and the product of the molar yield high, fixed less waste, easily to obtain high-purity product. (by machine translation)
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Paragraph 0021; 0022; 0023; 0024; 0025; 0026
(2017/06/02)
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- A bimetallic system for the catalytic hydroxylation of remote primary C- H bonds in functionalized organics using dioxygen
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In a mixture of trifluoroacetic acid and water, the combination of metallic palladium and copper chloride catalyzes the hydroxylation of remote primary C-H bonds of a variety of acids, alcohols, and aliphatic halides, in the presence of carbon monoxide and dioxygen. Experiments suggest that the principal role of metallic palladium is to generate hydrogen peroxide in situ and that the species responsible for the remote hydroxylation of the substrate by hydrogen peroxide is copper chloride. The unusual preference for the catalytic hydroxylation of primary C-H bonds was also found in an experiment involving competition between ethane and either cumene or p- isopropylbenzoic acid: even though the solution concentration of ethane was significantly lower than the competing substrate, the vast majority of the oxidation product (ethanol) was derived from ethane. In the reactions studied, acetic acid and formic acid were formed through C-C cleavage steps. An examination of the site of C-C cleavage in propionic acid indicated that both C-C bonds were being broken.
- Shen, Chengyu,Garcia-Zayas, Eduardo A.,Sen, Ayusman
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p. 4029 - 4031
(2007/10/03)
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- Initiators of addition of sodium hydrogen sulfite to allyl alcohol
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Synthesis of a versatile sulfoalkylating agent, 1,3-propanesultone, was studied.
- Baranovskaya
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p. 2047 - 2048
(2007/10/03)
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- N-Nitroso Sultams: On the Direction of Approach of Nucleophiles to the Sulfonyl Group
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The N-nitroso derivatives of propanesultam, butanesultam, and pentanesultam were synthesized along with N-nitropropanesultam and N-nitro-N-methylmethanesulfonamide.The decompositions of the N-nitroso sultams, wich increase in rate with increasing ring size, yield the corresponding sultones and also varying amounts of regenerated sultams.These reactions are discussed in terms of higher energy pathway involving approach of the nucleophile in a direction between of sulfonyl oxygens (on the O, O, N face) and a lower energy pathway involving the conformer which permits approach of the nucleophile trans to and colinear with one of the coordinate covalent oxygen atoms (on R, O, N face). The mechanisms of the decomposition of the N-nitro sulfonamides and the tosyloxy diimide N-oxides are also discussed.N-nitrosopropanesultam (and the butyl analoque) are potent inhibitors of proteinase α-chymotrypsin.
- White, Emil H.,Lim, Hyung M.
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p. 2162 - 2166
(2007/10/02)
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