- 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 0034
(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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Paragraph 0027; 0035-0036; 0039; 0045-0046; 0049; 0056-0057;
(2021/01/24)
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- Preparation method of 4-thiophenyl-o-phenylenediamine
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The invention provides a preparation method of 4-thiophenyl-o-phenylenediamine, wherein the preparation method comprises the steps: by taking 2-nitro-4-thiocyano aniline and aniline as initial raw materials, firstly, reacting 2-nitro-4-thiocyano aniline with sodium sulfide to obtain 3-nitro-4-amino thiophenol sodium, and reacting aniline with sodium nitrite under an acidic condition to generate benzene diazonium chloride; and then condensing the benzene diazonium chloride and the 3-nitro-4-amino thiophenol sodium to obtain 2-nitro-4-thiophenyl aniline, and then carrying out a Raney nickel hydrogenation reduction reaction to obtain the 4-thiophenyl-o-phenylenediamine. The method has the characteristics of high economic benefit, low three-waste amount, low cost and the like, the total yield can reach 64.58%, and the method belongs to the technical field of organic chemical industry.
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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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- A preparation method of curing melanotumor
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The invention discloses a preparation method of fenbendazole and provides a brand-new synthesis route of the fenbendazole. The fenbendazole is prepared from m-dichlorobenzene as a starting material through the steps of nitrification, condensation, amination, reduction and cyclization. The preparation method is characterized in that the starting material m-chloroaniline in the existing industrial route is changed to the cheap m-dichlorobenzene; the existing reduction technology with sodium sulfide dihydrate is changed to the clean and high-efficiency reduction technology; and the new synthesis technology is concise and simple, high in efficiency, slight in pollution, high in quality, and suitable to industrial production.
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Paragraph 0039; 0040
(2016/10/27)
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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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- 5(6)-Benzene ring substituted benzimidazole-2-carbamate derivatives having anthelmintic activity
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Benzene ring substituted benzimidazole-2-carbamate derivatives represented by the formula: SPC1 Where R is a lower alkyl group having 1 to 4 carbon atoms; R1 is --SR5 or --OR5 ; and R5 is aryl. The R1 substitution is at the 5(6)-position. The compounds are useful as pesticides, particularly as anthelmintic and antifungal agents.
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