Methanol → (2S)-2-(4-bromophenyl)-4-[(1R)-1-phenylethyl]morpholine

Participants

Reaction Steps

To a ice-cooled solution of (6S)-6-(4-bromophenyl)-4-((1R)-1-phenylethyl) morpholin-3-one (intermediate 6, 92 g) obtained in step 1-10 in tetrahydrofuran (400 ml) was added dropwise over 30 minutes a borane-tetrahydrofuran complex (1.0 M solution in tetrahydrofuran, 600 ml, 600 mmol). After being warmed to room temperature and stirred for 2 hours, the mixture was ice-cooled again and added dropwise with methanol (70 ml). The solvent was evaporated under reduced pressure. The residue was added with methanol (750 ml) and 1 M aqueous sodium hydroxide (280 ml). The mixture was stirred at 80° C. for one hour, during which period 1 M aqueous sodium hydroxide (70 ml) was added 3 times in every 15 minutes. After the mixture was cooled to room temperature, methanol was evaporated under reduced pressure and the resulting solution was extracted with ethyl acetate. The organic layers was washed with water and brine, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure to give (2S)-2-(4-bromophenyl)-4-((1R)-1-phenylethyl)morpholine (intermediate 7, 68 g, yield 88% from intermediate 5) as white crystals.

Provenance & Evidence