Method for preparing 3.5-dimethylpyrazole
A technology of dimethylpyrazole and solvent, applied in 3 fields, can solve the problems of troublesome separation, a large amount of solvent, low yield and the like, and achieves the effects of convenient operation, low cost and high yield
Inactive Publication Date: 2009-07-01
卢宪春
View PDF0 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
In Rothenberg.J.Prakt.Chem.1895.52 (2) document, the preparation method of 3,5-dimethylpyrazole is that acetylacetone and hydrazine hydrate are synthesized in ethanol solvent, and this technique needs a large amount of solvent and low yield
Morgan and Ackerman.J.Chem.Soc.1923.123.1308, Zimmerman and Lochte, J.Am.Chem.Soc, 1938.60.2456.Org.Syntheses.Coll.Vol four 1963.351. and other documents, with acetylacetone and hydrazine sulfate in Synthesis of 3,5-dimethylpyrazole in alkaline solution, the product contains a large amount of inorganic salts, the separation is troublesome, and the yield is low
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0008] 3, the preparation of 5-dimethylpyrazole:
[0009] In the reaction pot, add 1000Kg water, 370Kg acetylacetone, appropriate amount of glacial acetic acid, and then add hydrazine hydrate dropwise, so that the reaction temperature does not exceed 50°C. °C, vacuum-dried after centrifuging and rinsing, and analyzed by HPLC, the content of 3,5-dimethylpyrazole was greater than 99%, and the yield was more than 90%.
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention relates to the field of chemical industry, in particular to a preparation method of 3,5-dimethylpyrazole. In solvent water, use acetylacetone and hydrazine hydrate as raw materials, add acid catalyst glacial acetic acid, and synthesize it at a reaction temperature of 50°C. The invention has the advantages of using water as a solvent, low cost, no inorganic salts, convenient operation, and using glacial acetic acid as a catalyst with high yield and good purity.
Description
technical field [0001] The invention relates to the field of chemical industry, in particular to a preparation method of 3,5-dimethylpyrazole. Background technique [0002] 3,5-Dimethylpyrazole has a wide range of uses, mainly used in the manufacture of coatings and paints, and can also be used in pesticides and medicines. In Rothenberg.J.Prakt.Chem.1895.52 (2) document, the preparation method of 3,5-dimethylpyrazole is that acetylacetone and hydrazine hydrate are synthesized in ethanol solvent, and this technique needs a large amount of solvent and the yield is low. Morgan and Ackerman.J.Chem.Soc.1923.123.1308, Zimmerman and Lochte, J.Am.Chem.Soc, 1938.60.2456.Org.Syntheses.Coll.Vol four 1963.351. and other documents, with acetylacetone and hydrazine sulfate in 3,5-dimethylpyrazole is synthesized in alkaline solution, and the product contains a large amount of inorganic salts, and the separation is troublesome and the yield is low. Contents of the invention [0003] In ...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): C07D231/12
Inventor 刘中明
Owner 卢宪春
Features
- R&D
- Intellectual Property
- Life Sciences
- Materials
- Tech Scout
Why Patsnap Eureka
- Unparalleled Data Quality
- Higher Quality Content
- 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.
© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com