85-47-2Relevant academic research and scientific papers
Rearrangement of Aromatic Sulfonate Anions in the Gas Phase
Binkley, Roger W.,Flechtner, Thomas W.,Tevesz, Michael J. S.,Winnik, Witold,Zhong, Boyu
, p. 769 - 772 (1993)
Collisionally activated dissociation of deprotonated aromatic sulfonic acids in the gas phase causes rearrangement and fragmentation to produce the corresponding phenoxide ions.The mechanism for this reaction has been investigated and the results of this study favor initial intramolecular nucleophilic addition of a sulfonate oxygen atom to the aromatic ring, a process which is followed by heterolytic cleavage of the carbon-sulfur bond to rearomatize the ring.The product from this addition-elimination sequence is the anion of a sulfurous acid half-ester, which loses SO2 to generate the corresponding phenoxide ion.
Oxidative Degradation of Azo Dyes in Aqueous Solution by Water-Soluble Iron Porphyrin Catalyst
Saha, Tapan Kumar,Frauendorf, Holm,Meyer, Franc
, p. 2870 - 2881 (2021/07/14)
Textile and food industries produce a significant volume of effluents containing azo dyes and other pollutants. These effluents are serious environmental threats, and new methods for their treatment and for the degradation of azo dyes are thus attracting much attention. The current study deals with the oxidative degradation of azo dyes by meso-tetrakis(1-methylpyridinium-4-yl)prophyrinatoiron(III), [FeIII(tmpyp)], and meta-chloroperoxy benzoic acid (m-CPBA) in aqueous solution at room temperature. The catalytic degradation of azo dyes was investigated by using rapid-scan stopped-flow spectrophotometry as a function of solution pH, [catalyst], [m-CPBA], [dye] and [surfactants]. To obtain mechanistic insight, the reaction between [FeIII(tmpyp)] and m-CPBA was also studied in aqueous solution in absence of azo dyes. Spectral analyses and kinetic data show that [FeIII(tmpyp)] is transformed into the transient intermediate [FeIV(O)(tmpyp)].+ (a compound I analog) within 20–30 ms followed by the formation of relatively stable [FeIV(O)(tmpyp)] (a compound II analog). Batch experiments reveal that the dye degradation rate is influenced by the solution pH and the concentrations of [FeIII(tmpyp)], m-CPBA, dye, and surfactants. On the basis of the kinetic and spectroscopic data, a mechanistic scheme for the dye degradation reaction and a steady-state rate equation are proposed. The products resulting from oxidative degradation of the azo dye amaranth have been analyzed by HPLC-UV-HRMS.
Aryl and alkyl sulfonic acid compounds as well as construction method adopting inorganic sulfur salt and application
-
Paragraph 0046-0049; 0104-0107, (2020/09/16)
The invention discloses aryl and alkyl sulfonic acid compounds as shown in a formula (1) and a synthesis method thereof. The method comprises the following step: aromatic iodine and an inorganic sulfur source or alkyl bromide and an inorganic sulfur source as reaction raw materials react in a solvent under the action of alkali, a catalyst or an additive to obtain a series of aryl and alkyl sulfonic acid compounds. According to the method, the aryl and alkyl sulfonic acid compounds are constructed in one step by taking an inorganic sulfur reagent as a sulfur source, so that the defect of the mode in which the aryl and alkyl sulfonic acid compounds are synthesized by taking concentrated sulfuric acid, chlorosulfonic acid or sulfur dioxide gas and the like as sulfonating reagents in the priorart is avoided. The aryl and alkyl sulfonic acid compounds developed by the invention can be used for synthesizing aryl and alkyl sulfonic acid drug analogues.
Cornforth and Corey-Suggs reagents as efficient catalysts for sulfonation of aromatic and heteroaromatic compounds using NaHSO3 under solvent free and microwave conditions
Fatima, Touheeth,Duguta, Govardhan,Purugula, Venkanna,Yelike, Hemanth Sriram,Kamatala, Chinna Rajanna
, p. 1001 - 1006 (2020/07/27)
Cornforth and Corey-Suggs reagents Pyridinium Dichromate (PDC) and Pyridinium Chlorochromate (PCC) were explored as efficient catalysts for sulfonation of aromatic and heteroaromatic compounds using NaHSO3 in aqueous acetonitrile medium at room temperature within 1–4 h, while microwave assisted reactions took place within 1–4 min under solvent-free conditions. These observations indicate significant rate accelerations in microwave assisted reactions. which were explained due to the bulk activation of molecules induced by insitu generated high temperatures and pressures when microwaves are transmitted through reaction medium.
Sustainable access to sulfonic acids from halides and thiourea dioxide with air
Zhang, Hui,Wang, Ming,Jiang, Xuefeng
supporting information, p. 8238 - 8242 (2020/12/29)
A sustainable and mild one-step strategy is explored for the synthesis of aryl and alkyl sulfonic acids using a facile combination of halides and sulfur dioxide surrogates under air. The cheap industrial material thiourea dioxide was employed as an eco-friendly and easy-handling sulfur dioxide surrogate, while air was used as a green oxidant. Both aryl and alkyl sulfonic acids were obtained under transition metal-catalyzed or transition metal-free conditions. Mechanistic studies demonstrated that sulfinate was involved as an intermediate in this transformation. Notably, this protocol has been applied to the late-stage sulfonation of the drugs naproxen, isoxepac and ibuprofen.
Synthetic process of naphthol
-
Paragraph 0017; 0018; 0019; 0020; 0021; 0022, (2017/08/29)
The invention discloses a synthetic process of naphthol. The process comprises the followings steps: sulfonation, neutralization, alkali fusion, and acidification. The sulfonation step comprises the following steps: a sulfonation reaction is carried out for naphthalene and sulfuric acid whose mass fraction is 98% in the existence of a water carrying agent, a characteristic that the water carrying agent and water form an azeotrope is applied, water which is generated in the reaction is separated continuously from a reaction system, and naphthalene and sulfuric acid are nearly reacted completely. Obtained 1-naphthalenesulfonic acid is neutralized, alkali fusion and acidification are directly carried out in order to obtain a naphthol crude product. The process has the advantages of simplified operation, little low of naphthalene and sulfuric acid, high utilization rate, high naphthalene conversion rate which reaches 94% or above, low amount of waste water, and a few amount of sodium sulfate waste water which is only generated after multiple circulations.
Method for continuously producing 1-naphthalene sulfonic acid
-
Paragraph 0072-0078, (2017/06/19)
The invention belongs to the field of organic matter sulfonation, and particularly relates to a method for continuously producing 1-naphthalene sulfonic acid. The method particularly includes the steps: adding naphthalene and sulfur trioxide into a sulfonation reactor for sulfonation reaction to obtain mixture containing the 1-naphthalene sulfonic acid; adding solvents into the mixture to perform solid-liquid separation to obtain the 1-naphthalene sulfonic acid and mother liquor; circulating the mother liquor to sulfonation reaction. The naphthalene is in a solid or melted liquid state, and the sulfur trioxide is in a gas or liquid state. The method for continuously producing the 1-naphthalene sulfonic acid avoids waste acid, can also realize tail gas treatment and solvent recovery and is efficient, environmentally friendly and suitable for large-scale continuous production, solvent loss is reduced, complicated separation steps are omitted, and production cost is greatly reduced.
Preparation method of 1-naphthylamine-5-sulfonic acid
-
Paragraph 0055; 0056; 0057; 0058; 0059; 0060; 0061-0063, (2016/10/17)
The invention discloses a preparation method of 1-naphthylamine-5-sulfonic acid. The preparation method comprises the following steps of step one, sulfonation: refined naphthalene is added after sulfuric acid is added to a sulfonation pot and stirred, steam is turned on for warming, and the reaction is kept for a period of time; then second batch of sulfuric acid is added, and the reaction is kept for a period of time; step two, nitrification: nitric acid is added, the temperature is controlled, and the reaction is kept for a period of time; the acidity is enabled to reach 45%-46%, and the amino value is larger than or equal to 410 g/kg; step three, neutralization: dolomite suspension liquid is added, excess sulfuric acid and hydrogen ions on the sulfonic acid group are neutralized, and the end point is reached if the color of congo red test paper doesn't change into blue; step four, reduction: iron powder is added, the reduction rate is controlled to be above 99%, and the amino value is controlled to be between 90 g/t to 110 g/t; step five, acidification: 1-naphthylamine-8-sulfonic acid is subjected to acidification separation to prepare 1-naphthylamine-5-sulfonic acid mother liquor; step six, the 1-naphthylamine-5-sulfonic acid mother liquor is acidized to further prepare the 1-naphthylamine-5-sulfonic acid.
Method for hydrogen catalyzed preparation of 1-naphthylamine-8-sulfonic acid
-
Paragraph 0011; 0012; 0013; 0014; 0015; 0016; 0017, (2016/10/20)
The invention discloses a method for hydrogen catalyzed preparation of 1-naphthylamine-8-sulfonic acid. The method includes the reduction steps of: placing a solution containing 1-sulfonyl-8-nitronaphthalene in a reduction pot, adding nickel powder, conducting starting and stirring, enclosing the reduction pot and pumping vacuum, then introducing hydrogen and maintaining the pressure at 1.2-1.3MPa, heating the mixed liquid to a temperature of 100-110DEG C, pumping out the mixed liquid from the bottom continuously and letting it flow into the reduction pot from the top, at the same time pumping out the gas from the top continuously and blowing the gas into the reduction pot from the bottom. The method for hydrogen catalyzed preparation of 1-naphthylamine-8-sulfonic acid provided by the invention can prepare the 1-naphthylamine-8-sulfonic acid product meeting the market requirements, and also can overcome the disadvantages of existing iron powder catalyzed preparation methods.
A dilute sulfuric acid recovery method for using (by machine translation)
-
Paragraph 0021, (2016/11/24)
The invention discloses a method for recovering and utilizing dilute sulfuric acid, characterized in that comprises the following steps: in the reaction with rectification, the dilute sulfuric acid and double-ring aromatic hydrocarbon, or/and polycyclic aromatic hydrocarbon in the distillation together with, in the rectification process, the water as the light component, from the rectification tower, the concentration of sulfuric acid in the kettle, the kettle warmly rise; when cauldron mass concentration of sulfuric acid in > 63% time, the temperature of the kettle for 150-175°C, sulfuric acid and double-ring aromatic hydrocarbon, or/and polycyclic aromatic sulfonation reaction occurs, the water is generated at the same time, and the concentration of sulfuric acid in the rectification heating water outlet, so cycle, until complete reaction consumption of sulfuric acid in the kettle. In the invention, the dilute sulfuric acid rectification concentrated use and double ring/multi-ring aromatic sulfonated combination, does not need high-temperature, can be realized by using concentrated and dilute sulfuric acid. (by machine translation)
