- Process for synthesizing propiconazole
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The invention discloses a process method for synthesizing propiconazole. To 2, 4 -dichloro acetophenone serves as a starting raw material, and cyclization, bromination and condensation to prepare propiconazole comprises the following steps: 2, 4 -dichloro acetophenone and 1, 2 - pentanediol in a solvent benzene, cyclization reaction is carried out under the action of a catalyst to obtain a cyclized product. A bromide is obtained by brominating the cyclized product with bromine. The bromide, triazole in the solvent are subjected to a condensation reaction under the action of a base and a phase transfer catalyst to obtain propiconazole. The method is mild in reaction condition, simple and convenient to operate, capable of avoiding the generation of propiconazole isomer, improving the purity of propiconazole, high in reaction yield, reduced by-products and reduced in production cost.
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Paragraph 0027-0032
(2021/09/29)
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- Synthesis technology for propiconazole
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The invention discloses a synthesis technology for propiconazole. The synthesis technology comprises the following steps: 1) successively adding an organic solvent, 2,4-dichlorophenone, hydrogen peroxide and a catalyst into a reaction tank and dropwise adding liquid bromine; 2) keeping temperature at 40-45 DEG C for 1-8 hours and adding a reducing agent; 3) drying with magnesium sulfate and performing reduced pressure distillation; 4) cooling, separating and drying, thereby acquiring alpha-2,4-dichlorophenone; 5) adding methylbenzene, alpha-2,4-dichlorophenone, 1,2-pentanediol and p-toluene sulfonic acid into the reaction tank, heating till reflux reaction for 4-8 hours, and performing reduced pressure distillation, thereby acquiring 2-(2,4-dichlorophenyl)-2-bromine methyl-4-propyl-1,3-dioxolame; 6) adding dimethyl sulfoxide, catalyst, 1,2,4-triazole potassium and 2-(2,4-dichlorophenyl)-2-bromine methyl-4-propyl-1,3-dioxolame into the reaction tank, keeping temperature at 140 DEG C for5-10 hours, cooling, filtering, performing reduced pressure distillation, generating a salt with nitric acid, acidizing and neutralizing, performing reduced pressure distillation and purifying, thereby acquiring propiconazole. The synthesis technology disclosed by the invention is simple, environment-friendly and high in product purity.
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Paragraph 0018; 0020; 0022
(2019/06/30)
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