Borane → (1S)-3-amino-1-phenylpropan-1-ol

Participants

Reaction Steps

To 10 ml of a THF solution of 1.47 g (10.0 mmol) of the (S)-3-hydroxy-3-phenylpropanenitrile obtained in Example 1, slowly added was 1.23 ml (13.0 mmol) of borane.dimethylsulfide complex. After removing the dimethylsulfide by reducing the pressure, the reaction mixture was refluxed for 2.5 hours. The reaction was stopped by the addition of a methanol/hydrochloric acid solution, and the methanol was distilled off under vacuum. After neutralizing with a 5N aqueous solution of sodium hydroxide, the solvent was distilled off, a further aqueous solution of sodium hydroxide was added to make the reaction solution basic, and this was then extracted with methylene chloride. This methylene chloride solution was dried with anhydrous sodium sulfate, and the solvent was then distilled off under vacuum to give 1.47 g of (S)-3-amino-1-phenylpropanol. The amino group of (S)-3-amino-1-phenylpropanol was monobenzoylated by reaction with benzoyl chloride, and when it was analyzed using a CHIRALCEL OB column (manufactured by Daicel Chemical Industries, Ltd., eluant; n-hexane:2-propanol=90:10) it was found that the optical purity was 98% ee.

Provenance & Evidence