- Synthetic method of fenbendazole
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A synthetic method of fenbendazole belongs to the technical field of insect repellents, and specifically comprises the following steps: carrying out condensation reaction on 5-chloro-2-nitroaniline and a sodium thiophenol aqueous solution in a mixed solution of n-propyl alcohol and water to obtain 5-thiophenyl-2-nitroaniline; carrying out reduction reaction on the 5-thiophenyl-2-nitroaniline in a high-pressure kettle under the catalysis of raney nickel to generate 4-thiophenyl o-phenylenediamine; and mixing the 4-thiophenyl o-phenylenediamine and N-(trichloromethyl) methyl carbamate for a cyclization reaction to obtain fenbendazole; the method has the advantages that conditions are mild, operation is easy and convenient, ammonium chloride can be prevented from being generated in the cyclization process, and the three-waste cost is low; the generation of amine salt is avoided, and the treatment cost of three wastes is greatly reduced; and the yield of the fenbendazole can reach 84.27% to 89.99%, and the purity of the fenbendazole can reach 96.39% to 99.71%.
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Paragraph 0035-0052
(2021/08/14)
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- Fenbendazole production process and production device
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The invention discloses a fenbendazole production process and a production device, the production process comprises a nitration reaction, a condensation reaction, a reduction reaction and a cyclization reaction, and finally the fenbendazole is obtained through centrifugation and drying. The production device comprises a plurality of reaction kettles, a distillation device and a distillation recovery device, the reaction kettles are respectively a nitration reaction kettle, a condensation reaction kettle, a cyclization reaction kettle and a reduction reaction kettle, and the nitration reactionkettle, the condensation reaction kettle, the cyclization reaction kettle, the distillation device and the reduction reaction kettle are sequentially communicated through feeding pipes. According to the process, the product purity can be improved; few types of chemical reagents are adopted, and methanol and methylbenzene are recycled so that reagent consumption is reduced, waste is avoided, and the process is economical and environmentally friendly; the process route is simple, the production period is shortened, and the production efficiency is improved; according to the production device, automatic feeding is achieved through the feeding mechanism, the automation degree is high, manual operation is reduced, and efficiency is improved.
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- A preparation method of a dog or CAT
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The invention discloses a dog or CAT a kind of preparation method. Characterized in that (1) in order to inter-bromobenzene as the starting material, nitric acid/sulfuric acid system through the nitration reaction, process for preparing the intermediate 1 (2, 4 - dibromo nitrobenzene); (2) using the intermediate 1 as raw materials, through the ammonia in methanol solution of ammoniation reaction, to prepare the intermediate 2 (5 - bromo - 2 - nitroaniline); (3) using the intermediate 2 and thiophenol sodium solution as raw materials, through the condensation reaction, process for preparing the intermediate 3 (4 - phenylthio - 2 - nitroaniline); (4) intermediate 3 through the palladium catalytic hydrogenation reduction, to produce intermediate 4 (4 - phenylthio - 1, 2 - phenylenediamine); (5) intermediate 4 and melamine-based methyl formate solution, through the cyclization reaction, the profuse benzene reaches zuo generating products. The method clean environment, the production cost is low, with a purity of 99.5% or more, the yield is not lower than 84.0%.
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- Highly water-soluble prodrugs of anthelmintic benzimidazole carbamates: Synthesis, pharmacodynamics, and pharmacokinetics
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Highly water-soluble prodrugs 1a-g of anthelmintic benzimidazole carbamates 2a-g were synthesized. These prodrugs combine high aqueous solubility and stability with high lability in the presence of alkaline phosphatases. The veterinary utility of 1a was shown by a pharmacodynamic and pharmacokinetic study performed in swine. Comparable anthelmintic efficacy was observed with prodrug 1a or the parent fenbendazole 2a. The pharmacokinetic results showed that 2a is better absorbed when derived from 1a than when applied as such.
- Chassaing,Berger,Heckeroth,Ilg,Jaeger,Kern,Schmid,Uphoff
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p. 1111 - 1114
(2008/09/20)
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- Efficient Synthesis in Three Steps and Spectral Determination of Methyl-5-[(o-, m-, and p-substituted-phenylthio]-2-Benzimidazolecarbamates
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The preparation and spectral properties of ten novel methyl 5-[(o-, m-, and p-substituted)-phenylthio]-2-benzimidazolecarbamates with possible pharmacological activity as antihelmintics is described; by condensation and cyclization between 5-methylthioures sulfate chloroformic acid methyl ester and 3,4-diaminophenyl-substituted-phenylthio ether dissolved in ethanol. The structures of all final products were corroborated by ir; 1H-nmr, 13C-nmr and ms.
- Cortes, Eduardo Cortes,Mendoza, Rafael Sosa,Gutierrez, Maximiliano Santibanez,De Cortes, Olivia Garcia-Mellado
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p. 273 - 276
(2007/10/03)
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- 1,5-diphenyl-3-formazancarbonitril parasiticides
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The present invention is directed to the use of 1,5-diaryl-3 -formazancarbonitrile compounds for the control of parasites in vertebrate animals.
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- Anthelmintic 5-heterocycliothio and oxy-2-carbalkoxyaminobenzimidazles
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New methyl benzimidazolecarbamate compounds having a heterocyclic thio or oxy moiety at position 5, useful as anthelmintics are described. Methyl-5-(pyridylthio)- and 5-(pyridylmethylthio)-benzimidazolecarbamates are preferred.
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