PROCESS FOR PREPARING (E)-(5,6-DIHYDRO-1,4,2-DIOXAZINE-3-YL) (2-HYDROXYPHENYL) METHANONE O-METHYL OXIME

• Main Authors: A., Sai SRIKANTH, Christopher, Lynn LARSON, Avinash, Shesharo MANE, Sagi SATEESH, Cameron GIBB, Sampadarao, Ananda RAO, Sankar BALAKRISHNAN, K. N. RAVIKUMAR, Vic PRASAD, Jivan, Dhanraj PAWAR
• Format: Patent
• Language: English; Spanish
• Published: 04.05.2018
• Subjects: CHEMISTRY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY

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);. Se describe un proceso para preparar O-metil oxima de (E)-(5,6-dihidro-1,4,2-dioxazin-3-il)(2-hidroxifenil)metanona que incluye: (i) hacer reaccionar Ometil oxima de benzofuran-3(2H)-ona (1) con al menos un nitrito seleccionado entre nitrito de n-butilo y nitrito de terc-butilo, en presencia de un alcóxido metálico para formar O3-metil dioxima de (2Z,3Z)-2,3-benzofuran-diona (2) como isómero predominante; (ii) hacer reaccionar la O-metil dioxima de (2Z,3Z)-2,3-benzofuran-dion a (2) con 2-haloetanol para formar O2-(2-hidroxietil) O3-metil dioxima de (2Z,3Z)-benzofuran-2,3-diona (3); y (iii) hacer reaccionar la O2-(2-hidroxietil) O3-metil dioxima de (2Z,3Z)-benzofuran-2,3-diona (3) con un ácido para formar O-metil oxima de (E)-(5,6-dihidro-1,4,2-dioxazin-3-il)(2-hidroxifenil)meta nona (4);.