2820-37-3Relevant articles and documents
Preparation method of 3, 4-dimethylpyrazole and phosphate thereof
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Paragraph 0054; 0057; 0059; 0062; 0064; 0067; 0069; 0072, (2021/02/06)
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.
Preparation method of 3,4-dimethylpyrazole and preparation method of 3,4-dimethylpyrazole phosphate
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Paragraph 0058; 0059, (2019/10/01)
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.
Method for producing substituted pyrazoles
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, (2008/06/13)
Pyrazole derivatives are prepared by reacting carbonyl compounds R1—C(O)—CH(R2)—CH2R3with hydrazine, its hydrate or its salts in 30 to 100% by weight sulfuric acid in the presence of catalytic amounts of iodine or of an iodine compound.