Borane → 4-Amino-3-(3,4-dichlorophenyl)-1-butanol

Participants

Reaction Conditions

Reaction Steps

350 ml of a 1 molar solution of BH3 in THF are added to a solution of 244 g (1 mol) of (-)-3-cyano-3-(3,4-dichlorophenyl)propionic acid in 500 ml of THF, cooled to 0° C. When the evolution of hydrogen has ceased, 650 ml of the borane solution are added at 20° C., followed by 1000 ml at 40° C. When the reaction is complete, the excess borane is destroyed by the addition of methanol and the reaction mixture is concentrated to dryness. The concentrate is dissolved in 500 ml of water, acidified with hydrochloric acid and washed twice with 250 ml of toluene. The aqueous phase is rendered alkaline with sodium hydroxide and extracted with twice 400 ml of dichloromethane. The organic phase is washed with water, separated off by decantation, dried over magnesium sulfate and concentrated under vacuum to give 159 g (yield: 68%) of the expected product. Chiral purity by HPLC: 99%.

Provenance & Evidence