反应详情

温度

40 °C

31 g of 4-methoxyquinaldine (prepared from 4-hydroxyquinaldine by the method of M. Maurin, A. Ch. 4 [11] (1935), 301 and 335) are taken up in 80 ml of chloroform at room temperature, and 42 g of 85% strength m-chloroperbenzoic acid are added a little at a time, with stirring. The mixture is heated at 40° C. for 2 hours and is then cooled to 20° C. and brought to pH 6-7 with about 9 g of NaOH in 50 ml of H2O. The organic phase is separated off, dried with Na2SO4, filtered and concentrated. 34 g of crude product remain, and are recrystallized from toluene with addition of a small amount of solid KOH. 12 g of pure 4-methoxyquinaldine-N-oxide are obtained. Melting point 131°-132° C.

1. temperatureis then cooled to 20° C.
2. customThe organic phase is separated off
3. dry with materialdried with Na2SO4
4. filtrationfiltered
5. concentrationconcentrated
6. customare recrystallized from toluene with addition of a small amount of solid KOH