Trifluoroacetic acid → (2S,4S)-Methyl 2-amino-4-phenylhexanoate

Participants

Reaction Steps

To a solution of trifluoroacetic acid (3.4 ml) in water (440 ml) was added dropwise over 15 min a solution of (2R,5S)-2-isopropyl-3,6-dimethoxy-5-((S)-2-phenyl-butyl)-2,5-dihydro-pyrazine (4.69 g, 14.8 mmol) in acetonitrile (75 ml). The mixture was stirred overnight at room temperature then made basic by addition of saturated aqueous sodium carbonate solution and the mixture was extracted with ethyl acetate. The phases were separated and the organic phase was washed sequentially with water and with saturated brine, then dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by column chromatography (SiO2, EtOAc/heptane) to yield a yellow oil (2.78 g, 85%); MS (ISP): 222.1 ([M+H]+).

Provenance & Evidence