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

• Main Authors: PAWAR JIVAN DHANRAJ, MANE AVINASH SHESHARO, SRIKANTH A SAI, PRASAD VIC, RAVIKUMAR K N, RAO SAMPADARAO ANANDA, LARSON CHRISTOPHER LYNN, BALAKRISHNAN SANKAR, SATEESH SAGI, GIBB CAMERON
• Format: Patent
• Language: Chinese; English
• Published: 13.02.2018
• 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 leastone 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); 描述了用于制备(E)-(5，6-二氢-1，4，2-二嗪-3-基)(2-羟苯基)甲酮O-甲基肟的方法，其包括：(i)在金属醇盐存在下，使苯并呋喃-3(2H)-酮O-甲基肟(1)与选自亚硝酸正丁酯和亚硝酸叔丁酯的至少种亚硝酸酯反应以形成作为主要异构体的(2Z，32)-2，3-苯并呋喃-二酮O3-甲基二肟(2)；(ii)使所述(2Z，3Z)-2，3-苯并呋喃-二酮O-甲基二肟(2)与2-卤代乙醇反应以形成(2Z，3Z)-苯并呋喃-2，3-二酮O2-(2-羟乙基)O3-甲基二肟(3)；和(iii)使所述(2Z，3Z)-苯并呋喃-2，3