- High-value utilization method of sodium 2-mercaptoacetate in thionocarbamate production tail liquid
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The invention belongs to wastewater treatment, and particularly discloses a high-value utilization method of sodium 2-mercaptoacetate in thionocarbamate production tail liquid. According to the method, sodium 2-mercaptoacetate in the thionocarbamate production tail liquid is used as a raw material and reacts with thiocyanate and a halogenating reagent to obtain the S-carboxyethyl-N-alkanoyl dithiocarbamate. The method is simple to operate and high in efficiency, solves the problem that the sodium 2-mercaptoacetate in the thionocarbamate production tail liquid is difficult to recover, and can realize high-value utilization of the sodium 2-mercaptoacetate.
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Paragraph 0079-0080
(2021/08/11)
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- Co-production method of thionocarbamate and benzyl thioether acetic acid and application of the method
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The invention discloses a co-production method of thionocarbamate and benzyl thioether acetic acid and application of the method. The method comprises the following steps: with xanthate and benzyl chloride as initial raw materials, and performing esterification reaction to obtain benzyl xanthate; carrying out ammonolysis on benzyl xanthate by using primary amine to obtain thionocarbamate and benzyl mercaptan; further adding sodium chloroacetate into the mixture for reaction, thus generating benzyl thioether sodium acetate; finally, performing liquid separation to obtain the thionocarbamate collecting agent and a water phase containing benzyl thioether sodium acetate. The benzyl thioether sodium acetate-containing water phase can further react with benzyl chloride to obtain benzyl thioetherbenzyl acetate or be acidified and esterified with fatty alcohol to generate benzyl thioether alkyl acetate, and the two ester compounds can be subjected to hydroximation to synthesize benzyl thioether ethyl hydroximic acid. The method solves the problems of difficult recovery, difficult utilization and unpleasant smell of the byproduct sulfhydryl compound in the traditional thionocarbamate process, realizes co-production of benzyl thioether acetic acid and derivatives thereof, and improves the reaction efficiency.
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Paragraph 0075; 0076
(2019/12/02)
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- Method for utilizing byproduct 2-sodium thioglycollate in production process of thionocarbamate
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The invention belongs to wastewater treatment and in particular discloses a method for utilizing a byproduct 2-sodium thioglycollate in the production process of thionocarbamate. The method comprisesthe following steps: by taking a byproduct 2-sodium thioglycollate in the production process of thionocarbamate as a raw material, enabling the byproduct to react with a halogenation reagent so as toobtain alkyl thioether acetic acid; performing esterification on the alkyl thioether acetic acid with methanol so as to obtain alkyl thioether methyl acetate; and further enabling the alkyl thioethermethyl acetate to react with hydroxylamine hydrochloride, so as to obtain alkyl thioether ethyl hydroximic acid. By adopting the method, the problem that the byproduct 2-sodium thioglycollate in a process of thionocarbamate is hard to recycle can be solved, the utilization rate of the byproduct is increased, and the environment can be protected.
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Paragraph 0070-0070
(2019/12/25)
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- Method for preparing thionocarbamates and co-producing 2-mercaptoethanol or O-alkylthioethyl xanthogenate
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The invention belongs to field of mineral flotation collecting agent materials and in particular discloses a method for preparing thionocarbamates. The method comprises the following steps: carrying out esterification reaction on xanthogenate and 2-halogenated ethanol to obtain O-alkyl-S-hydroxyethyl xanthogenate; carrying out ammonolysis reaction on the O-alkyl-S-hydroxyethyl xanthogenate and fatty amine to obtain a mixture of the thionocarbamates and 2-mercaptoethanol; after carrying out alkali washing on the mixture of the thionocarbamates and the 2-mercaptoethanol, carrying out oil-water separation, wherein an oil phase is the thionocarbamates and a water phase is 2-hydroxyethanethiol salt; carrying out acid washing on the 2-hydroxyethanethiol salt to obtain 2-mercaptoethanol. The invention further provides O-alkylthioethyl xanthogenate which is prepared by enabling the 2-hydroxyethanethiol salt and alkyl halide to react to obtain 2-alkylthioethyl ethanol and enabling the 2-alkylthioethyl ethanol to react with carbon disulfide and alkali. According to the method provided by the invention, the yield of the prepared thionocarbamates, 2-mercaptoethanol and O-alkylthioethyl xanthogenate is high and the purity is high; a product is easy to separate and purity and co-production is realized; the cost is saved and the reaction efficiency is also improved; the method is green and environmentally friendly.
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Paragraph 0097; 0098
(2018/10/11)
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- Method for producing thionocarbamate and dibenzyl disulfide
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The invention discloses a method for producing thionocarbamate and dibenzyl disulfide. The method comprises the following steps: carrying out an esterification reaction on alkyl xanthate and benzyl halide to obtain alkyl benzyl xanthate; carrying out an aminolysis reaction on the alkyl benzyl xanthate and fatty amine to obtain a thionocarbamate and benzyl mercaptan mixture; and carrying out an oxidation reaction on the thionocarbamate and benzyl mercaptan mixture and hydrogen peroxide, and carrying out liquid-solid separation to obtain a solid which is the dibenzyl disulfide product and a liquid, and allowing the liquid to stand for oil and water layering in order to obtain an oil phase which is the thionocarbamate product. The dibenzyl disulfide product and thionocarbamate product obtained through the method have high yield and high purity, and the method has the advantages of easiness in separation of the products in the preparation process, environmental protection, high atom economy property, low production cost, and easiness in realization of industrial production.
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Paragraph 0057-0059
(2017/06/02)
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- Method for preparing thionocarbamate and trithiocarbonate
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The invention discloses a method for preparing thionocarbamate and trithiocarbonate. The method comprises the following steps: carrying out an esterification reaction on alkyl xanthate salt and a halogenation reagent to obtain alkyl xanthate ester; carrying out an aminolysis reaction on the alkyl xanthate ester and fatty amine to obtain a thionocarbamate and mercaptan compound mixture; and carrying out an addition reaction on the thionocarbamate and mercaptan compound mixture and carbon disulfide in the presence of caustic alkali, and carrying out solid-liquid separation to obtain a liquid phase which is the thionocarbamate product and a solid phase which is the trithiocarbonate product. The products prepared through the preparation method have high yield and high purity, and the method allows the two high-efficiency collectors comprising thionocarbamate and trithiocarbonate to be simultaneously produced, and has the advantages of easiness in separation of the products, high atom economy property, low production cost, and easiness in realization of industrial production.
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Paragraph 0059-0061
(2017/06/20)
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- Synthesis of some thionocarbamates from O-isopropyl xanthate and amines using Pd/Ti-HMS-10 as catalyst in water
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Abstract: Ti-HMS materials with different Si/Ti ratio (5, 10, 20 and 30) were prepared and used as the support for a palladium-containing (1?wt%) catalyst. The materials, analyzed by XRD and SEM techniques, were tested in the synthesis of some thionocarba
- Ranjbar-Karimi, Reza,Asadi, Masumeh,Talebizadeh, Alireza,Saeednia, Samira,Sayedbagheri, Sayed Mohammad
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p. 1867 - 1874
(2016/08/25)
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- A synthesis of N-alkyl and N,N-dialkyl O-ethyl thiocarbamates from diethyl dixanthogenate using different oxidants
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A novel synthesis of N-alkyl and N,N-dialkyl O-ethyl thiocarbamates from diethyl dixanthogenate and primary and secondary amines, using three oxidizing systems, has been developed on the laboratory scale, and the method using sodium hypochlorite has been applied on a semi-industrial scale. The effect of the oxidizing agents, sodium hypochlorite, in-situ-generated peracetic acid, and the manganese(II) acetate/oxygen system on product purity and yield was studied. The results obtained by use of these three methods were compared with those obtained by reaction of sodium ethyl xanthogenacetate and amines, and of sodium ethyl xanthate with amines in the presence of sulfated nickel zeolite catalyst. The reaction mechanism of sodium hypochlorite oxidation has been established on the basis of isolation of reaction intermediates and determination of their structure by use of Fourier-transform infrared, 1H and 13C NMR, and mass spectrometric methods. The suggested sodium hypochlorite and manganese(II) acetate/oxygen systems have many advantages in comparison with commercial and catalytically promoted synthetic methods, because they are new ecologically friendly syntheses. Springer-Verlag 2010.
- Milosavljevic, Milutin M.,Sovrlic, Milica,Marinkovic, Aleksandar D.,Milenkovic, Dragan D.
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experimental part
p. 749 - 755
(2011/07/08)
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- Catalytic synthesis of thionocarbamates from xanthates and amines
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Catalytic processes for the synthesis of thionocarbamates by contacting xanthates, and amines, especially primary amines in the presence of at least one suitable catalyst. Suitable catalysts for these processes include finely divided metallic catalysts such as suspended nickel and precious metal(s); for example, Raney Nickel or platinum/palladium on carbon support. Reaction is carried out at a most preferred temperature of from about 70° C. to about 80° C. and for about 8 hours to about 12 hours for example.
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