- Synthesis method of flubendazole
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The invention relates to a synthesis method of flubendazole, which comprises the following steps of 1) adding a reductant and a methyl ester reactant into a reaction flask, adding formic acid, heatingto 80 DEG C, and keeping the temperature for 2.5-3 hours, wherein the molar ratio of the reductant to the methyl ester to the formic acid is 1: 1.2: 16-20, and the reaction equation is shown in the specification, and 2) injecting the solution in the reaction bottle into methanol, cooling to room temperature, and filtering to obtain the flubendazole. The step of acetic acid condensation is omitted, excessive formic acid is directly added to synthesize the flubendazole in one step, the reaction steps are simple, the operation rate is high, and the yield is high and is about 86.9-87.6%.
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Paragraph 0002; 0008
(2020/12/30)
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- Preparation method of flubendazole
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The invention relates to a preparation method of flubendazole. The preparation method comprises the following steps: dropwise adding thionyl chloride into a reaction system taking 4-chloro-3-nitrobenzoic acid and o-dichlorobenzene as solvents, wherein DMF (Dimethyl Formamide) is used as a reaction catalyst; then dropwise adding an acylated reaction solution into a fluorobenzene and aluminum trichloride system and carrying out Friedel-Crafts reaction; adding ammonia water, methane and a Friedel-Crafts product into a closed reactor for carrying out amination reaction; adding aminate, the methaneand a palladium carbon catalyst into a high-pressure hydrogenation reactor for reducing; adding a cyclization agent into a reduced reaction solution from which a catalyst is removed for cyclizing; finally, dropwise adding hydrogen peroxide into the cyclized reaction solution for oxidizing. The preparation method disclosed by the invention has the advantages that firstly, during cyclization reaction, an intermediate has an passivation action of carbonyl, so that the cyclization reaction is smoother and reaction time is greatly shortened; secondly, nitro is reduced by adopting a hydroreductionmethod which has better economic and environment-friendly properties compared with a traditional sulfuration alkaline method; thirdly, the cyclization agent adopts lower-price methyl cyanocarbamate,so that production cost is reduced.
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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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- Synthesis and anthelminthic acitivity of alkyl-(5-acyl-1-benzimidazol-2-yl) carbamates
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A series of alkyl-(5-acyl-l-H-benzimidazol-2-yl)-carbamates were prepared and screened for anthelminthic activity. Some of them were found to be fully active at low, atoxic oral dose levels against gastro-intestinal nematodes. The activity against Syphacia muris and Strongyloides ratta is indicated. From these studies methyl (5-benzoyl-1-H-benzimidazol-2-yl) carbamate (mebendazole) and methyl [5-(4-fluorobenzoyl)-1-H-benzimidazol-2-yl]carbamate (flubendazole) were selected for detailed investigation.
- Raeymackers,Van Gelder,Roevens,Janssen
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p. 586 - 594
(2007/10/05)
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