Preparation method of probenazole

Abstract

The invention provides a preparation method of probenazole. The method comprises the following steps: by taking saccharin as an initial raw material, chlorinating with thionyl chloride in 1, 4-dioxaneto obtain a chloride, adding a high-boiling-point solvent to remove the solvent dioxane and excessive thionyl chloride, directly carrying out substitution reaction with a sodium salt or a potassium salt of allyl alcohol, and carrying out centrifugal desalination and cooling recrystallization to directly obtain high-purity probenazole. The preparation method is capable of solveing the problem of difficult kettle rotation caused by chloride solidification in the prior art, avoiding the generation of allyl chloride during etherification by allyl alcohol, and reducing the water washing procedurein the traditional method. Compared with the traditional method, the advantages are that the preparation method is simple and convenient to operate, high in yield, less in three wastes and high in purity of the obtained product, greatly saves the production cost and the environmental protection cost, and is easy to realize industrialization.

Description

technical field [0001] The invention relates to the field of allyl benzothiazole production, in particular to a preparation method of allyl benzothiazole. Background technique [0002] Allylbenzothiazole, its chemical name is 3-(prop-2-enyloxy)-1,1-dioxylidenebenzo[d]isothiazole, its CAS accession number is [27605-76-1], its molecular formula for C 10 h 9 NO 3 S, its structural formula is as follows: [0003] [0004] Allylbenzothiazole itself does not have direct bactericidal activity, but it can stimulate the potential of plants, so it is called a disease resistance activator. As an inducer, it induces plants to produce defense effects against rice blast and some bacterial diseases, thereby inhibiting the occurrence and development of diseases. Allylbenzothiazole is a low-toxicity pesticide, acute oral LD ​​in male mice 50 2750mg / kg, 3000mg / kg for female mice, low toxicity and safety to non-pathogenic microorganisms and warm-blooded animals, and belongs to an env...

AI Technical Summary

Problems solved by technology

[0006] The problem that current technology exists is (1), after chlorination finishes, excess thionyl chloride will be thoroughly distilled off, otherwise residual thionyl chloride will react with allyl alcohol to generate allyl chloride when the second step replaces, In order to remove the thionyl chloride, the 1,4-dioxane has to be evaporated to dryness. In the later stage of distillation, due to the high melting point of the chlorinated product, it will suddenly solidify and damage the stirring blade or block the pipeline during the process of turning the kettle. , which is a difficult problem to overcome in production

[0013] If dichloromethane is removed under reduced pressure, the cost of its condensation or the loss of dichloromethane will be increased

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