- Short and Safe Synthesis of Ethyl 3-(Trifluoromethyl)pyrazine-2-carboxylate
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The treatment of ethyl 2-hydroxyimino-4,4,4-trifluoro-3-oxobutanoate (3) with trialkyl phosphites, ethylenediamine, and an excess of a carboxylic acid in pyridine or picoline leads to the formation of an intermediate, which can be aromatized to a pyrazine by treatment with bromine or other oxidants. This synthesis can be performed either with the isolated oxime 3 or from ethyl 4,4,4-trifluoro-3-oxobutanoate (1) in a one-pot fashion, without any solvent change and without having to isolate any intermediates.
- Zaragoza, Florencio,Gantenbein, Annabelle
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- Synthesis method of bixpyrazinam precursor
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The invention discloses a synthesis method of a bixpyrazinam precursor. The method comprises the following steps: by using cheap and easily available copper nitrate and ammonium persulfate as oxidants, oxidizing ethyl trifluoroacetoacetate in situ to obtain ethyl trifluoroacetyl oxo-acetate, and carrying out condensation/aromatization reaction on the ethyl trifluoroacetyl oxo-acetate and ethylenediamine to obtain a drug intermediate 3-(trifluoromethyl)-2-pyrazinecarboxylate. According to the method, expensive or dangerous reagents are not used, the preparation process is simple, low in cost and safe, and meanwhile, the prepared product is high in purity and good in economic benefit. The method is expected to provide a simpler and more efficient way for industrial production of the bactericide bixpyrazamine precursor.
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Paragraph 0048-0091
(2021/11/19)
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- Trifluoromethyl-containing pyrazinamide compound, preparation method and applications thereof, and bactericide
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The present invention relates to the field of pesticide bactericides, and discloses a trifluoromethyl-containing pyrazinamide compound, a preparation method and applications thereof, and a bactericide, wherein the compound has a structure represented by a
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- Iodine-containing pyrazinamide compound, preparation method and applications thereof, and bactericide
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The present invention relates to the field of pesticide bactericides, and discloses an iodine-containing pyrazinamide compound, a preparation method and applications thereof, and a bactericide, wherein the compound has a structure represented by a formula (I). According to the present invention, the iodine-containing pyrazinamide compound with the completely-new structure is designed by introducing the pyrazine ring of NNF-0721 and the diphenyl ether fragment having broad biological activity, and can be used as the completely-new succinate dehydrogenase inhibitor or bactericide. The formula (I) is defined in the specification.
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- Pyrazinamide compound, preparation method and applications thereof, and bactericide
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The present invention relates to the field of pesticide bactericides, and discloses a pyrazinamide compound, a preparation method and applications thereof, and a bactericide, wherein the compound hasa structure represented by a formula (I). The preparatio
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- Pyrazinamide compounds, preparation method and application thereof as well as bactericide
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The invention relates to the field of pesticide bactericides and discloses pyrazinamide compounds, a preparation method and an application thereof as well as a bactericide. The compounds have the structure shown in formula (I). The pyrazinamide compounds with the novel structure are designed by introducing pyrazine ring fragments in Pyradiflumid and diphenyl ether fragments with wide bioactivity,and the pyrazinamide compounds can be used as novel SDHIs (succinate dehydrogenase inhibitors) or bactericides.
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- Pyrazinamide compounds and preparing method and application thereof and bactericide
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The invention relates to the field of pesticide bactericides, and discloses a pyrazinamide compound and a preparing method and application thereof and a bactericide. The pyrazinamide compound has thestructure shown in the formula (I) or the formula (II) or the formula (III). According to the pyrazinamide compound and the preparing method and application thereof and the bactericide, by introducingpyrazine ring fragments and and diphenyl ether fragments with the wide biological activity in NNF-0721, and the pyrazinamide compound with the brand-new structure is designed; the pyrazinamide compound can serve as a brand-new succinodehydrogenase inhibitor or a bactericide. The formula is defined in the description.
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- METHOD FOR THE PREPARATION OF 3-(TRIFLUOROMETHYL)PYRAZINE-2-CARBOXYLIC ACID ESTERS
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The invention discloses a method for the preparation of 3-(trifluoromethyl)pyrazine-2-carboxylic acid esters starting from alkyl 4,4,4-trifluoro-2-(hydroxyimino)-3-oxobutanoates by reaction with ethylenediamine.
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Page/Page column 14-28
(2018/03/25)
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