反应详情

温度

24 °C

A solution of 2,4-dichloro-benzaldehyde O-methyl-oxime (1.0 g, 4.9 mmol), prepared as described in example P10a, in acetic acid (7.1 ml) was treated at 10° C. with sodium cyanoborohydride (615 mg, 9.8 mmol) added in small portions over 10 minutes and the resulting solution was stirred at 24° C. for 7 hours. The solvent was evaporated under reduced pressure (co-evaporation with toluene twice) and the residue was slurried with water. The aqueous phase was extracted with dichloromethane (2×20 ml), washed with brine and dried over anhydrous Na2SO4. After removal of the solvent, the residue (1510 mg) was purified by flash chromatography over silica gel (eluent: c-hexane/ethyl acetate 9:1). 690 mg (68.0% of theory) of N-(2,4-dichloro-benzyl)-O-methyl-hydroxylamine was obtained in form of a clear liquid.

1. additionadded in small portions over 10 minutes
2. customThe solvent was evaporated under reduced pressure (co-evaporation with toluene twice) and the residue
3. extractionThe aqueous phase was extracted with dichloromethane (2×20 ml)
4. washwashed with brine
5. dry with materialdried over anhydrous Na2SO4
6. customAfter removal of the solvent
7. customthe residue (1510 mg) was purified by flash chromatography over silica gel (eluent: c-hexane/ethyl acetate 9:1)