42110-76-9Relevant academic research and scientific papers
Method for synthesizing 5-difluoromethoxy-3-trifluoromethyl-1-methyl pyrazole
-
Paragraph 0033-0035, (2019/06/27)
The invention relates to the field of organic synthesis, in particular to a method for synthesizing 5-difluoromethoxy-3-trifluoromethyl-1-methyl pyrazole. The method includes the following steps of: 1-methyl pyrazole reacts with a halogenating agent under the action of a metal reagent to generate 5-halogenation-1-methyl pyrazole, wherein the 5-halogenation-1-methyl pyrazole reacts with difluoro methyl alcohol under the catalyzing of alkali to obtain 1-methyl-5-difluoromethoxazole; the 1-methyl-5-difluoromethoxazole reacts with a trifluoromethylating reagent under the action of visible light catalysis and a photocatalyst to obtain 5-difluoromethoxy-3-trifluoromethyl-1-methyl pyrazole. The method has the advantages that by redesigning the route, the method can obtain the 5-difluoromethoxy-3-trifluoromethyl-1-methyl pyrazole with high yield and high selectivity by using raw materials which are cheaper and easier to obtain.
Recent developments in the chemistry of heteroaromatic N -oxides
Wang, Youliang,Zhang, Liming
, (2015/02/19)
Selected developments in the chemistry of heteroaromatic N-oxides since 2001 are presented in this review. The use of these N-oxides, both in late-transition-metal-catalyzed oxidations of carbon-carbon triple bonds and in regioselective C-H functionalizations of the heteroarene, are contemporary topics of interest and the focus of the discussion. 1 Introduction 2 Synthesis of Heteroaromatic N-Oxides 2.1 Direct Oxidation of Hindered Heteroarenes 2.2 Through Construction of Heteroaromatic Rings 3 Heteroaromatic N-Oxides as Oxidants 3.1 Alkyne Oxidation 3.2 Allene Oxidation 3.3 Carbene Oxidation 4 Heteroaromatic N-Oxides as Substrates 4.1 Deoxygenative ortho-C-H Functionalization with Prior Activation 4.2 Deoxygenative ortho-C-H Functionalization with Nonstabilized Carbanions 4.3 Nondeoxygenative C-H Functionalization 4.3.1 ortho-C-H Functionalization 4.3.2 N-Oxide Directed ortho-Alkyl C-H Functionalization 4.3.3 N-Oxide Directed Remote C-H Functionalization 4.4 1,3-Dipolar Cycloaddition 5 Conclusion and Outlook.
Synthesis of 2-Alkylpyrazole-1-oxides: A Facile Access to 1-Alkyl-5-halopyrazoles
Eskildsen, Joergen,Vedsoe, Per,Begtrup, Mikael
, p. 1053 - 1056 (2007/10/03)
Selective N-alkylation of 1-hydroxypyrazole 1 into the corresponding 2-alkyl-pyrazole-1-oxides 2a-f has been achieved by treatment with alkyl bromides in the absence of base. Subsequent deoxygenation/halogenation into 1-alkyl-5-halopyrazoles 3a-d and 4a-d using phosphorus oxyhalides is described.
