- Preparation method of 3, 4-dimethylpyrazole and phosphate thereof
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The invention discloses a preparation method of 3, 4-dimethylpyrazole and phosphate thereof, which comprises the following steps: S1. making 2-butanone react with formate at -10 to 50 DEG C in a reaction solvent under the condition of keeping alkaline by using an alkaline substance, carrying out extraction separation, adding an alkylation reagent, continuing the reaction to obtain a reaction solution, and carrying out post-treatment to obtain a solution of an alkene ether compound, and S2, making the alkene ether compound prepared in the step S1 react with hydrazine hydrate or hydrazine salt at the temperature of -10 to 60 DEG C after the pH value is adjusted to 2-9, adding the alkaline substance to adjust the pH value to 7-11 after the reaction is finished, and carrying out post-treatmentto obtain the 3, 4-dimethyl pyrazole. The preparation method disclosed by the invention has the remarkable advantages of cheap raw materials, simplicity and convenience in operation, high yield, simplicity in three-waste treatment, high product quality, capability of recycling the solvent and the like, and is suitable for industrial production.
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Paragraph 0054; 0058-0059; 0063-0064; 0068-0069; 0073
(2021/02/06)
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- Preparation method of 3, 4-dimethylpyrazole and phosphate thereof
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The invention relates to a preparation method of 3, 4-dimethylpyrazole and phosphate thereof, and the method of the 3, 4-dimethylpyrazole comprises the following steps: 1) reacting 2-butanone, phosphorus oxychloride and N, N-dimethylformamide in a reaction solvent at -10 to 70 DEG C, and separating and extracting to obtain a solution of an aldehyde alkenyl chloride compound; and 2) adjusting the pH value of the aldehyde alkenyl chloride compound prepared in the step 1) and hydrazine hydrate or hydrazine salt to 2-10, reacting at 10-60 DEG C, adding an alkaline substance to adjust the pH valueto 6-11 after the reaction is completed, and carrying out post-treatment to obtain the 3, 4-dimethylpyrazole. According to the preparation method, by reacting the 2-butanone, phosphorus oxychloride and N, N-dimethylformamide to obtain the alkenyl chloride compound, reacting the alkenyl chloride compound with the hydrazine hydrate or hydrazine salt, carrying out post-treatment to obtain the 3, 4-dimethylpyrazole, and salifying the 3, 4-dimethylpyrazole and phosphoric acid, the 3, 4-dimethylpyrazole phosphate is obtained. The method is cheap and easily available in raw material, short in step, simple and convenient to operate, high in yield, high in product quality and suitable for industrial production, and the solvent can be recycled.
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Paragraph 0027-0030; 0033-0035; 0037-0039; 0041-0043; 0045
(2020/03/17)
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- Preparation method of 3,4-dimethylpyrazole and preparation method of 3,4-dimethylpyrazole phosphate
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The invention discloses a preparation method of 3,4-dimethylpyrazole and a preparation method of 3,4-dimethylpyrazole phosphate. The methods comprise the following steps: performing condensation by using 2-butanone and formate as raw materials, performing aminolysis, performing cyclization to prepare the 3,4-dimethylpyrazole; and performing a salt forming reaction on the 3,4-dimethylpyrazole and phosphoric acid to obtain the 3,4-dimethylpyrazole phosphate. The preparation method of the 3,4-dimethylpyrazole and the preparation method of the 3,4-dimethylpyrazole phosphate provided by the invention have the significant advantages that the raw materials are cheap and easy to obtain, the operation is simple and convenient, the yield is high, the product quality is high, the solvent can be recovered and reused, and the methods are suitable for industrial production.
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Paragraph 0050-0053
(2019/10/01)
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- Method for preparing 3, 4-dimethylpyrazole and phosphate thereof
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The invention discloses a method for preparing 3, 4-dimethylpyrazole and phosphate thereof. The method for preparing the 3, 4-dimethylpyrazole includes the steps: (1) feeding 2-butanone, aldehyde andalkali solution into a microchannel reactor and performing aldehyde ketone condensation reaction to produce 4-hydroxy-3-methyl-2-butanone salt; (2) mixing reaction liquid obtained in the step (1) andacid liquid in the microchannel reactor to obtain 4-hydroxy-3-methyl-2-butanone water solution; (3) performing reaction on hydrazine hydrate and the 4-hydroxy-3-methyl-2-butanone water solution in themicrochannel reactor, mixing reaction liquid with the alkali solution and hydrogen peroxide, and performing oxidative dehydrogenation reaction to obtain 3, 4-dimethylpyrazole water solution; (4) performing organic extraction and distillation on the 3, 4-dimethylpyrazole water solution to obtain the 3, 4-dimethylpyrazole. According to the method, reaction time is greatly shortened, the yield and the purity of products are ensured, and continuous production can be realized.
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Paragraph 0103; 0104; 0110; 0111; 0119; 0127
(2019/04/17)
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