反应详情

At 20° C., 19.8 g (0.3 mol) of potassium hydroxide pellets are added to a suspension of 38.4 g (0.2 mol) of benzofuran-2,3-dione 3-(O-methyl-oxime) 2-oxime in 400 ml of water and the mixture was stirred for 30 minutes, on which a solution forms. At 20° C., 17.6 g (0.4 mol) of ethylene oxide are introduced over a period of 75 minutes, and the mixture is stirred at 20° C. overnight, on which a precipitate forms. The mixture is then stirred at 60° C. for 11 hours, on which the precipitate redissolves. The solution is cooled and acidified to pH 5-6 with glacial acetic acid. The crystalline product is filtered off with suction, washed with 300 ml of water a little at a time and dried at 45° C. in a vacuum drying cabinet. 19.6 g (39.3% of theory) of (5,6-dihydro-[1,4,2]dioxazin-3-yl)-(2-hydroxy-phenyl)-methanone O-methyl-oxime are obtained.

1. stirringthe mixture is stirred at 20° C. overnight, on which a precipitate forms
2. stirringThe mixture is then stirred at 60° C. for 11 hours, on which the precipitate
3. dissolutionredissolves
4. temperatureThe solution is cooled
5. filtrationThe crystalline product is filtered off with suction
6. washwashed with 300 ml of water a little at a time
7. customdried at 45° C. in a vacuum
8. customdrying cabinet