- Method for preparing sulfenamide rubber vulcanization accelerator by heterogeneous catalysis of oxidation of molecular oxygen
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The invention relates to a method for preparing a sulfenamide rubber vulcanization accelerator by heterogeneous catalysis of oxidation of molecular oxygen, and belongs to the field of chemical engineering. The method adopts heterogeneous metal cobalt-based nano material as a catalyst, in an oxygen or air environment, a sulfydryl compound and amine are reacted for 0.5-16 hours in an organic phase under the conditions that the atmospheric pressure is 1-7 and the temperature is 40-100 DEG C to prepare the sulfenamide rubber vulcanization accelerator. The catalyst has the characteristics of high catalytic activity, high reaction efficiency, low cost, easiness in obtaining and reusability; and the sulfenamide synthesis steps are simple, the conversion rate is high, byproducts are few, and the method is more suitable for industrial production.
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Paragraph 0022-0024; 0026
(2021/08/07)
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- Method for preparing NS through UHP oxidation
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The invention aims to provide a novel method for preparing NS through UHP oxidation. A UHP solution formed by urea and hydrogen peroxide is used as an oxidizing agent to carry out an oxidation reaction on a raw material M and tert-butylamine at a certain temperature, the product NS is separated after the reaction is finished, a filtrate is subjected to concentration to recover tert-butylamine, anda mother liquor containing urea is obtained after mother liquor purification treatment operation and is reused. The method has the advantages of simplicity in operation, mild conditions, cleanness, environmental protection, no generation of waste salt, high product melting point, high product purity, and easy realization of industrialization. The UHP solution is used as the oxidizing agent, no waste salt or waste gas is generated, the urea-containing mother liquor is reused, and the three-waste problem is solved fundamentally. The urea is added, so that the effect of adjusting the oxidabilityof the hydrogen peroxide can be achieved, the reaction selectivity is improved, UHP can be formed by the urea and the hydrogen peroxide, the risk of direct oxidation of the hydrogen peroxide is reduced, and the safety of an oxidation process is improved.
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Paragraph 0030-0039
(2020/07/02)
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- Scalable electrochemical oxidant-and metal-free dehydrogenative coupling of S-H/N-H
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A practical and scalable electrochemical oxidation of S-H and N-H was developed. This oxidant- and catalyst-free electrochemical process enables S-N bond formation with inexpensive nickel electrodes in an undivided cell. This procedure exhibits broad substrate scopes and good functional-group compatibility. A 50 g scale oxidative coupling augurs well for industrial applications.
- Tang, Shanyu,Liu, Yan,Li, Longjia,Ren, Xuanhe,Li, Jiao,Yang, Guanyu,Li, Heng,Yuan, Bingxin
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supporting information
p. 1370 - 1374
(2019/02/14)
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- Continuous preparation method of N-tert-butyl benzothiazole sulfenamide
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The invention belongs to the technical field of refined chemical engineering and particularly relates to a continuous preparation method of N-tert-butyl benzothiazole sulfonamide (TBBS). By taking benzothiazole disulfide (a vulcanization accelerator DM), an organic solvent and tert-butylamine as raw materials and selecting an inorganic or organic alkaline catalyst, TBBS is synthesized in two continuous reactors; in the reaction process, an oxidant is not needed, and the added catalyst can be used repeatedly, the adding amount of the catalyst is 5-30% by weight of the added benzothiazole disulfide. According to a TBBS product synthesized by the method, the yield is stabilized in a range of 98-99.5%, methanol undissolved substance in the product is lower than 0.1%, in the process production,waste water is not generated, and the method is suitable for industrial production.
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Paragraph 0014-0017; 0020; 0021
(2018/05/15)
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- Preparation method of N-tert-butyl-2-benzothiazolesulfenamide
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The invention provides a preparation method of N-tert-butyl-2-benzothiazolesulfenamide, and relates to the technical field of rubber vulcanization accelerators. The preparation method of the N-tert-butyl-2-benzothiazolesulfenamide comprises the following steps: mixing 2-mercaptobenzothiazole, tert-butylamine and a catalyst; then, introducing oxygen; reacting to obtain the N-tert-butyl-2-benzothiazolesulfenamide, wherein the catalyst is a tetraphenylporphyrin metal complex. By adopting the method, toxic or dangerous oxidizing agents do not need to be used, an oxidizing effect can be achieved bytaking oxygen as an oxidizing agent under the catalytic action of the catalyst, and the generation of waste water is avoided; the preparation method has the advantages of low oxidizing agent cost andclean production.
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Paragraph 0071; 0073; 0074; 0076; 0078; 0080; 0082; 0084
(2018/06/26)
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- Reusable cobalt-phthalocyanine in water: Efficient catalytic aerobic oxidative coupling of thiols to construct S-N/S-S bonds
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A new aerobic oxidative coupling of thiols in water to construct sulfenamides or disulfides was developed, utilizing cobalt(ii)phthalocyanine-tetra-sodium sulfonate as the catalyst and O2 as the oxidant. The mother liquor could be recycled up to 20 times with negligible loss of activity and only a minor decrease of product yield.
- Dou, Yingchao,Huang, Xin,Wang, Hao,Yang, Liting,Li, Heng,Yuan, Bingxin,Yang, Guanyu
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p. 2491 - 2495
(2017/07/17)
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- Method for preparing rubber accelerator NS by utilizing micro-channel reactor
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The invention relates to the field of chemical synthesis and in particular discloses a method for preparing a rubber accelerator NS by utilizing a micro-channel reactor. According to the method for preparing the rubber accelerator NS by utilizing the micro-channel reactor, the micro-channel reactor formed by connecting a micro mixer and a micro reactor is used, and the method is characterized by comprising the following steps: dissolving an accelerator M in excessive tert-butylamine so as to form a solution, and feeding into the micro mixer with sodium hypochlorite for mixing by a metering pump; feeding the mixture into the micro reactor for carrying out an oxidizing reaction; and performing suction filtration, filter cake washing and drying after the reaction is ended, thereby obtaining the accelerator NS. According to the method disclosed by the invention, the accelerator NS is prepared by the micro-channel reactor, the reaction time and the reaction temperature are accurately controlled, the reaction time is shortened, the reaction conversion rate is improved, high reflux is realized, the product is stable in quality and high in safety, enlarged production is promoted, and the defects of the traditional reactor can be effectively overcome.
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Paragraph 0021; 0022; 0023; 0024; 0025
(2017/08/29)
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- Preparation method for N-tert-butyl benzothiazole sulfenamide
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The invention belongs to the technical field of fine chemical engineering and particularly relates to a method of preparing N-tert-butyl benzothiazole sulfonamide (TBBS) without an oxidant. In the invention, benzothiazole disulfide (vulcanization accelerator DM) and tert-butyl amine as raw materials are used for synthesizing the TBBS with an inorganic or an organic alkaline catalyst, wherein the reaction process is free of any oxidant and the added catalyst can be reused. The addition amount of the catalyst is 5-30% of the weight of the disulfide benzothiazole. By means of the method, the yield of the TBBS is 96-98.5%, is stable in insoluble-in-methane substances being 0.13-0.32%, is free of generation of waste water and is suitable for industrial production.
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Paragraph 0016
(2016/11/09)
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- Process for the production of sulfenamides
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Benzothiazole-2-sulfenamides are prepared by reacting a 2-mercaptobenzothiazole and a primary or secondary amine with oxygen in the presence of a catalyst, for example a metal phthalocyanine, in a reaction medium consisting of (i) a mixture of the amine and water in which the amount of water at the outset of the reaction is from 0.2 to 20% by weight of the mixture, or (ii) a mixture as defined in (i) diluted with an inert organic solvent miscible with the mixture, in a proportion of up to two parts by weight of the inert organic solvent per part by weight of the mixture.
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- Manufacture of sulfenamides
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Processes for the manufacture of sulfenamides by the oxidation of a mixture of 2-mercaptobenzothiazole and the appropriate amine in a critical amount of water and/or organic solvent produces a pure product of good quality and high yield. The amount of water should be in the range of from 10 to 30% by weight based on the total reaction mixture.
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- Process for the preparation of thiazolesulphenamides
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Thiazolesulphenamides, useful as rubber vulcanization accelerators, are made by reaction of a 2-mercapto-thiazole or a 2,2'-dithiazolyl disulphide with ammonia or a primary or secondary amine in the presence of oxygen and a copper catalyst of specified kind.
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