PROCESS FOR PREPARING (E)-(5,6-DIHYDRO-1,4,2-DIOXAZINE-3-YL) (2-HYDROXYPHENYL) METHANONE O-METHYL OXIME
A process for preparing (E)-(5,6-dihydro-l,4,2-dioxazin-3-yl)(2- hydroxyphenyl)methanone O-methyl oxime is described which includes: (i) reacting benzofuran-3(2H)-one O-methyl oxime (1) with at least one nitrite selected from n-butyl nitrite and tert-butyl nitrite, in the presence of a metal alkoxid...
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Main Authors | , , , , , , , , , |
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Format | Patent |
Language | English French |
Published |
08.12.2016
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Subjects | |
Online Access | Get full text |
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Summary: | A process for preparing (E)-(5,6-dihydro-l,4,2-dioxazin-3-yl)(2- hydroxyphenyl)methanone O-methyl oxime is described which includes: (i) reacting benzofuran-3(2H)-one O-methyl oxime (1) with at least one nitrite selected from n-butyl nitrite and tert-butyl nitrite, in the presence of a metal alkoxide to form (2Z,32)-2,3-benzofuran-dione O3-methyl dioxime (2) as the predominant isomer; (ii) reacting the (2Z,3Z)-2,3-benzofuran-dione O -methyl dioxime (2) with 2- haloethanol to form (2Z,3Z)-benzofuran-2,3-dione 02-(2-hydroxyethyl) O3 -methyl dioxime (3); and (iii) reacting the (2Z,3Z)-benzofuran-2,3-dione 02-(2-hydroxyethyl) & -methyl dioxime (3) with an acid to form (E)-(5,6-dihydro-l,4,2-dioxazin-3-yl)(2- hydroxyphenyl)methanone (9-methyl oxime (4);
L'invention concerne un procédé de préparation de O-méthyl-oxime de (E)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphényl)méthanone qui comprend : (i) la réaction de O-méthyl-oxime de benzofuran-3(2H)-one (1) avec au moins un nitrite choisi parmi le nitrite de n-butyle et le nitrite de tert-butyle, en présence d'un alcoxyde métallique pour former la O-méthyl dioxime de (2Z,3Z)-2,3-benzofurane-dione (2) comme isomère principal ; (ii) la réaction de la O-méthyl dioxime de (2Z,3Z)-2,3-benzofurane-dione (2) avec du 2-halogénoéthanol pour former de la 2-(2-hydroxyéthyl) O-méthyl dioxime de (2Z,3Z)-benzofurane-2,3-dione (3) ; et (iii) la réaction de la 2-(2-hydroxyéthyl) O-méthyl dioxime de (2Z,3Z)-benzofurane-2,3-dione (3) avec un acide pour former de la O-méthyl-oxime de (E)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphényl)méthanone (4). |
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Bibliography: | Application Number: WO2016IB00871 |