Phenylpropanolamine → (1S,2R)-2-amino-1-phenylpropan-1-ol

Temperature

40 °C

A mixture of 5.0 g of (±)-2-(1-naphthylmethyl)-6-phenylhexanoic acid and 2.27 g of (-)-norephedrine was dissolved in 50 ml of methanol, and the mixture was concentrated under reduced pressure. The residue was dissolved in 60 ml of ethyl acetate with heating to 40° C. and the solution was allowed to stand overnight at room temperature. The precipitate was collected by filtration and recrystallized three times from ethyl acetate to obtain 1.5 g of the norephedrine salt (melting point 128°-131° C.). The resulting salt was dissolved in 30 ml of methanol, and 5 ml of a 1N-hydrochloric acid was added to the solution. The mixture was extracted with diethyl ether, and the ethereal layer was washed with water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to obtain 0.95 g of (+)-2-(1-naphtylmethyl)-6-phenylhexanoic acid as a colorless viscous oil.

1. concentrationthe mixture was concentrated under reduced pressure
2. dissolutionThe residue was dissolved in 60 ml of ethyl acetate
3. filtrationThe precipitate was collected by filtration
4. customrecrystallized three times from ethyl acetate

ORD record

ord-d1e3147fb43d42f29be354744bda69ff

Source dataset

uspto-grants-1989_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04863904