- Isoxadifen-ethyl with few impurities and preparation method of ethyl isoxadifen-ethyl
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The invention relates to isoxadifen-ethyl with low content of impurity compounds shown in a formula (II), a preparation method of the isoxadifen-ethyl, a quantitative method of the compound shown in the formula (II), and application of the compound shown in the formula (II) as a standard substance to control the quality of the isoxadifen-ethyl.
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Paragraph 0016
(2021/07/21)
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- Oxidize Amines to Nitrile Oxides: One Type of Amine Oxidation and Its Application to Directly Construct Isoxazoles and Isoxazolines
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A facile oxidative heterocyclization of commercially available amines and tert-butyl nitrite with alkynes or alkenes leading to isoxazoles or isoxazolines is described. The unprecedented strategy of the oxidation of an amine directly to a nitrile oxide was used in this cyclization process. This reaction is highly efficient, regiospecific, operationally simple, mild, and tolerant of a variety of functional groups. Control experiments support a nitrile oxide intermediate mechanism for this novel class of oxidative cyclization reactions. Moreover, synthetic applications toward bioactive molecular skeletons and the late-stage modification of drugs were realized.
- Zhang, Xiao-Wei,He, Xiao-Lin,Yan, Nan,Zheng, Hong-Xing,Hu, Xiang-Guo
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p. 15726 - 15735
(2020/11/30)
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- Synthesizing method of isoxadifen-ethyl for industrialized production
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The invention provides a synthesizing method of isoxadifen-ethyl for industrialized production. The synthesizing method comprises the following steps of using chlorobenzene as a raw material, using tetrahydrofuran as a solvent, and reacting with magnesium, so as to obtain a phenyl magnesium chloride Grignard reagent; performing nucleophilic addition reaction with acetophenone to generate 1,1-diphenylethanol; adding p-toluenesulfonic acid to dewater, so as to generate 1,1-diphenylethene; reacting with ethyl 2-chloro-2-(hydroxyimino)acetate, so as to generate an isoxadifen-ethyl product, whereinthe purity can reach 99%.
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Paragraph 0010; 0024; 0028; 0029; 0039
(2018/09/12)
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- Form of isoxadifen-ethyl, a process for its preparation and use of the same
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A crystalline form of isoxadifen-ethyl of formula (I), the crystal preparation process, the analyses of the crystal through various analytical methods and using the crystal to prepare stable agrochemical formulation. The invention also describes the use of various solvents towards the crystalline form preparation conditions.
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Page/Page column 8
(2018/07/30)
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- PROCESS FOR PRODUCING ISOXAZOLINE DERIVATIVES
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A process for producing isoxazoline derivatives by ring-opening and cyclization of the corresponding cyclopropane derivatives with electrophilic nitrosylation reagents.
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Paragraph 0022
(2016/05/09)
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- Stereoselective synthesis of β,ε-dihydroxy-α-amino acids by ring opening of 4,5-dihydroisoxazolyl derivatives
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Enantiomerically pure β-(4,5-dihydroisoxazol-3-yl)-substituted β-hydroxy-α-amino acids were synthesised stereoselectively by means of an addition reaction between (5,5-disubstituted-4,5-dihydroisoxazol-3-yl)-carbaldehydes and (R)-(+)-2,5-dihydro-3,6-dimethoxy-2-isopropylpyrazine (Schoellkopf's reagent) as a chiral auxiliary. The addition gave mixtures of only two adducts with high diastereoselectivity. The steric configuration of the major diastereoisomer was assigned on the basis of spectroscopic data and the accepted model for the aldol condensation of the Schoellkopf's reagent. The subsequent acid-catalysed hydrolysis of the pyrazine ring led to a mixture of β-(4,5-dihydroisoxazol-3-yl)-β-hydroxy-α-amino methyl esters together with a mixture of two partially hydrolysed dipeptides. The final reductive cleavage of the 4,5-dihydroisoxazole ring of these compounds made it possible to obtain the methyl esters of β,ε-dihydroxy-γ-oxo-ε,ε-disubstituted α-amino acid derivatives.
- Cremonesi, Giuseppe,Croce, Piero Dalla,Fontana, Francesco,Fiorelli, Claudio,Rosa, Concetta La
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experimental part
p. 2850 - 2855
(2009/06/20)
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- Anti-influenza virus activities of 2-alkoxyimino-N-(2-isoxazolin-3-ylmethyl)acetamides
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A series of 2-alkoxyimino-N-(2-isoxazolin-3-ylmethyl)acetamides and related compounds were synthesized and their antiviral activities against human influenza A virus were assessed. Studies of the structure-activity relationships revealed the strongest antiviral activity when position-5 of the isoxazoline ring was substituted with a tert-butyl group. When the alkoxyimino moiety was substituted with a methyl, ethyl, isopropyl or allyl group, good antiviral activity was obtained. Among the geometrical isomers at the oxime moiety, the E-isomers were more active than the Z-isomers. Among the compounds examined, (E)-2-allyloxyimino-2-cyano-N-(5-tert-butyl-2-isoxazolin-3-ylmethyl)acetamide (1j) was the most active inhibitor with an EC50 of 3 μg/mL in vitro.
- Kai, Hiroyuki,Matsumoto, Hiroshi,Hattori, Naohiko,Takase, Akira,Fujiwara, Tamio,Sugimoto, Hirohiko
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p. 1997 - 2000
(2007/10/03)
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