反应详情

温度

25 °C

To 1-(2,4,6-trichloro-phenyl)-propan-2-one O-methyl-oxime prepared as described in example P4 (53.9 g; assay 99%; 0.20 mol) in methanol (100 g) was added hydrogen chloride gas (22.0 g; 0.60 mol), whereas internal temperature in maintained at 20-30° C. by external cooling. A colourless suspension was obtained. The reaction mixture was cooled to 15° C. and triethylamino borane (borane triethylamine complex; 27.6 g; assay 96%; 0.23 mol) was dosed in during 60 min maintaining internal temperature at 15° C. The reaction mass was stirred for another 2 hours allowing the mixture to warm to ambient temperature. Thereafter almost no starting material can be detected by HPLC. The reaction mixture was then added to preheated (85° C.) water (126 g) during 30 min. A steady stream of gas was evolved; at the same time solvent was distilled. Heating was continued and the temperature maintained at 85-90° C. for another 1 hour. Finally gas was no longer produced. The resulting mixture was cooled to 20-25° C. Sodium hydroxide (30% aqueous solution; 56.5 g; 0.42 mol) was carefully added in order to bring pH to 7.2-7.7. The resulting mixture was extracted with tert-butyl methyl ether (125 ml). Phases were allowed to separate. The (lower) aqueous phase was split of. The (upper) organic phase was washed with water (2×100 g) and evaporated. Crude O-Methyl-N-[1-methyl-2-(2,4,6-trichloro-phenyl)-ethyl]-hydroxylamine (53.9 g; assay 97.8%; yield 98.0%) was obtained as clear oil.

1. customA colourless suspension was obtained
2. temperatureThe reaction mixture was cooled to 15° C.
3. customwas dosed in during 60 min
4. temperaturemaintaining internal temperature at 15° C
5. temperatureto warm to ambient temperature
6. additionThe reaction mixture was then added
7. customduring 30 min
8. distillationat the same time solvent was distilled
9. temperatureHeating
10. temperaturethe temperature maintained at 85-90° C. for another 1 hour
11. customno longer produced
12. temperatureThe resulting mixture was cooled to 20-25° C
13. extractionThe resulting mixture was extracted with tert-butyl methyl ether (125 ml)
14. customto separate
15. customThe (lower) aqueous phase was split of
16. washThe (upper) organic phase was washed with water (2×100 g)
17. customevaporated