15803-27-7Relevant academic research and scientific papers
Preparation method of 3, 4-dimethylpyrazole-5-formate compound
-
Paragraph 0046-0060, (2021/05/22)
The invention provides a preparation method of a 3, 4-dimethylpyrazole-5-formate compound. According to the method, 2-butanone and oxalic acid diester serve as raw materials, a 3-methyl acetylacetonate compound is prepared in a high-yield and high-regioselectivity mode under the catalysis of an organic annular secondary amine catalyst, the 3-methyl acetylacetonate compound reacts with hydrazine, and the 3, 4-dimethylpyrazole-5-formate compound is prepared in a high-yield mode. According to the preparation method, organic nitrogen-containing cyclic secondary amine compounds such as pyrroline, piperidine and morpholine are used as catalysts, and alcohols such as methanol and ethanol are used as solvents for reaction. The method has the characteristics of relatively mild reaction conditions, simplicity and convenience in operation, high regioselectivity, high yield and the like, and the synthesized 3, 4-dimethylpyrazole-5-formate compound can be used for preparing cyenopyrafen acaricides.
Highly regioselective organocatalyzed synthesis of pyrazoles from diazoacetates and carbonyl compounds
Wang, Lei,Huang, Jiayao,Gong, Xiaojie,Wang, Jian
supporting information, p. 7555 - 7560 (2013/07/05)
A general, organocatalytic inverse-electron-demand [3+2] cycloaddition reaction between a range of carbonyl compounds and diazoacetates has been developed. This reaction is catalyzed by secondary amines as a "green promoter" to generate substituted pyrazoles with high levels of regioselectivity. It is noteworthy that this [3+2] cycloaddition reaction proceeds efficiently at room temperature with a simple and inexpensive catalyst. Considering the large variety and ready availability of the starting materials (e.g. ketones, β-ketoesters, β-diketones, and aldehydes), as well as the operational simplicity of this process, a convenient, practical, and highly modular pyrazole synthesis has been developed. We believe that this work will arouse more research interest in the organocatalytic synthesis of other biologically active heterocycles. Such studies are currently underway in our laboratory. Dipoles apart: In situ formed enamines react with diazoacetates under mild conditions to afford the corresponding polysubstituted pyrazoles in good-to-excellent yields through an inverse-electron-demand 1,3-dipolar cycloaddition process (see scheme). Copyright
PROCESS FOR THE SYNTHESIS OF SUBSTITUTED PYRAZOLES
-
Page/Page column 11, (2010/05/13)
A process for the preparation of 4,5-di- and 2,4,5-trisubstituted pyrazole 3-carboxylates from 3-acyloxirane-2-carboxylates and hydrazine compounds.
One-Flask, Consecutive and Sigmatropic Rearrangements for Conversions of Propargylic Alcohols into Two-Carbon-Extended 4-Oxo-2-alkenoate Esters. Use of a New 1-Chloro-1-ethoxy-2-sulfinylethylene
Posner, Gary H.,Carry, Jean-Christophe,Crouch, R. David,Johnson, Neil
, p. 6987 - 6993 (2007/10/02)
Seven differently substituted primary and secondary propargylic alcohols are shown to react with (arylsulfinyl)vinylic chloride 1a at 100 deg C for 1 h sequentially via a sigmatropic rearrangement and then a sigmatropic rearrangement to form 4
