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Method for preparing 3, 4-dimethylpyrazole and phosphate thereof

A technology of dimethylpyrazole and methyl group, applied in the field of fine chemical synthesis, can solve the problems of high price of 2-methyl-2-butenal, high requirements for anticorrosion and high risk, and achieves great industrial application value, High yield and purity, and the effect of shortening the reaction time

Active Publication Date: 2019-04-05
SINOCHEM AGRI LINYI R&D CENT CO LTD
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  • Abstract
  • Description
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Problems solved by technology

[0003] At present, there is the use of 2-methyl-2-butenal as a raw material, which is first reacted with hydrazine hydrate to obtain 3,4-dimethyl-3,4-dihydro-1H-pyrazole, and then in concentrated sulfuric acid A method for preparing 3,4-dimethylpyrazole at a high temperature under the catalysis of sodium iodide, but in this method, 2-methyl-2-butenal is expensive and prone to polymerization, and requires concentrated sulfuric acid and High temperature requires high anti-corrosion equipment and high risk; in addition, if concentrated sulfuric acid is used in the preparation of DMPP, a large amount of SO will be generated during the reaction process. 2 and other gases, a large amount of strong acid wastewater will be produced in the post-treatment process, and the operation steps are complicated, and continuous production cannot be carried out; in addition, there are also 2-butanone and paraformaldehyde as starting materials, which are Generate 3-methyl-3-buten-2-one, react with hydrazine hydrate, then use hydrogen peroxide to oxidatively dehydrogenate in alkaline environment to prepare 3,4-dimethylpyrazole, and then react with phosphoric acid to prepare DMPP, but The 3-methyl-3-buten-2-one in this method is easy to polymerize, not easy to preserve, and the operation steps are complicated, need to use a large amount of equipment such as reactors, and cannot be continuously produced, and the production efficiency is low

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  • Method for preparing 3, 4-dimethylpyrazole and phosphate thereof
  • Method for preparing 3, 4-dimethylpyrazole and phosphate thereof

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[0060] According to the method for preparing 3,4-dimethylpyrazole according to the above-mentioned embodiments of the present invention, 2-butanone and aldehyde are used as raw materials, and aldehyde-ketone condensation reaction, cyclization and oxidative desorption are carried out sequentially in a microchannel reactor. Hydrogen reaction is used to prepare 3,4-dimethylpyrazole, which not only has low raw material cost, but also does not need to use concentrated sulfuric acid, and has high safety; The reaction time can be greatly shortened, the selectivity of the reaction product can be significantly improved while the reaction efficiency is improved, and the product has a high yield and purity, thereby realizing the continuous production of 3,4-dimethylpyrazole, It has great industrial application value. Specifically, the yield of 3,4-dimethylpyrazole prepared by this method can reach more than 75%, and the purity of the prepared 3,4-dimethylpyrazole can reach more than 95%....

Embodiment 1

[0097] Preparation of 3,4-dimethylpyrazole phosphate (reference figure 2 , Synthesis of 4-hydroxyl-3-methyl-2-butanone in reaction area A, synthesis of 3,4-dimethylpyrazole in reaction area B, synthesis of 3,4-dimethylpyrazole phosphate in reaction area C):

[0098] (1) Synthesis of 4-hydroxyl-3-methyl-2-butanone

[0099] With 144Kg 2-butanone (2000mol), 150Kg mass fraction water is 40% formaldehyde aqueous solution (2000mol) joins in the corresponding storage tank, and 3.0Kg mass fraction is 10% NaOH solution and 3.1Kg mass fraction is 10 % HCl solution is added to the corresponding storage tank; then the reaction zone A of the microchannel reactor is preheated to 50-55°C, wherein the reaction zone A is composed of 5 microchannel reaction sheets with a liquid holding capacity of 100mL, wherein The acid solution is fed into the fourth sheet; the metering pump is started to feed the feed, and the feed rates of 2-butanone, formaldehyde, lye and acid solution are 1.78L / min, 1.5...

Embodiment 2

[0105] Preparation of 3,4-dimethylpyrazole phosphate (reference figure 2 , Synthesis of 4-hydroxyl-3-methyl-2-butanone in reaction area A, synthesis of 3,4-dimethylpyrazole in reaction area B, synthesis of 3,4-dimethylpyrazole phosphate in reaction area C):

[0106] (1) Synthesis of 4-hydroxyl-3-methyl-2-butanone

[0107] 144Kg 2-butanone (2000mol), 155Kg mass fraction water is 40% formaldehyde aqueous solution (2000mol) joins in the corresponding storage tank, and 3.1Kg mass fraction is 10% NaOH solution and 3.3Kg mass fraction is 10 % HCl solution was added to the corresponding storage tank; then the reaction area A of the microchannel reactor was preheated to 40°C, wherein the reaction area A was composed of 6 microchannel reaction sheets with a liquid holding capacity of 100mL, in which the acid solution Feed in the fourth piece; start the metering pump to feed, the feed volumes of 2-butanone, formaldehyde, lye, and acid are respectively 1.78L / min, 1.55L / min, 30mL / min an...

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Abstract

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.

Description

technical field [0001] The invention belongs to the technical field of fine chemical synthesis, and in particular relates to a method for preparing 3,4-dimethylpyrazole and its phosphate. Background technique [0002] 3,4-Dimethylpyrazole phosphate (DMPP) is a highly efficient, safe, non-toxic and cheap nitrogen fertilizer nitrification inhibitor developed by BASF in Germany. Adding nitrification inhibitor DMPP to fertilizer can control the tendency of ammonium nitrogen to Nitrate nitrogen transformation, so as to realize the stable supply of nitrogen, reduce the leaching loss of nitrate nitrogen, and the discharge of nitrogen oxides, so as to achieve the purpose of improving the utilization rate of chemical fertilizers, protecting the environment and promoting agricultural development. Entec uses the strengthening effect of plants to absorb ammonium nitrogen and nitrate nitrogen to obtain synergistic yield-increasing benefits. While reducing nitrogen use, crops also increas...

Claims

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Application Information

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IPC IPC(8): C07D231/12
CPCC07D231/12
Inventor 孙鹰翔魏延青刘晓波张西兴
Owner SINOCHEM AGRI LINYI R&D CENT CO LTD