反応式
[CH2:1]([O:3][C:4](=O)[CH2:5][O:6][C:7]1[CH:16]=[CH:15][CH:14]=[CH:13][C:8]=1C(OC)=O)[CH3:2].C(COC1C=CC=CC=1C(O)=O)(O)=[O:19].C(OC(=O)C)(=O)C.C([O-])(=O)C.[Na+]>>[C:1]([O:3][C:4]1[C:8]2[CH:13]=[CH:14][CH:15]=[CH:16][C:7]=2[O:6][CH:5]=1)(=[O:19])[CH3:2]参加物
実験手順
A synthesis of (E)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphenyl)methanone O-methyl oxime (13) is illustrated in Scheme 2A. According to the synthesis, methyl salicylate reacts with ethyl chloro acetate in the presence of potassium carbonate to give methyl 2-(2-ethoxy-2-oxoethoxy)benzoate (6). Hydrolysis of methyl 2-(2-ethoxy-2-oxoethoxy)benzoate (6) followed by a consecutive cyclization of 2-(carboxymethoxy)benzoic acid (7) with acetic anhydride in the presence of sodium acetate gives benzofuran-3-yl acetate (8) which is converted to benzofuran-3(2H)-one (9) by methanolysis. Treatment of benzofuran-3(2H)-one (9) with O-methylhydroxylamine and sodium acetate affords benzofuran-3(2H)-one O-methyl oxime (10) which is oxidized with tert-butyl nitrate in hydrochloric acid to yield (3E)-benzofuran-2,3-dione O3-methyl dioxime (11A). In the presence of potassium hydroxide, (3E)-benzofuran-2,3-dione O3-methyl dioxime (11A) opens ethylene oxide resulting (3E)-benzofuran-2,3-dione O2-(2-hydroxyethyl) O3-methyl dioxime (12A) that undergoes potassium hydroxide-catalyzed cyclization to provide (E)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphenyl)methanone O-methyl oxime (13).
出典と根拠
- ORDレコード
- ord-91e276be171c45e9ab3dfc29b1f68e87
- 出典データセット
- uspto-grants-2015_11
- 特許番号
- US09193698B2
関連ノート
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