HCID 54215249, compound → HCID 21153507, compound

Participants

Reaction Steps

The 1-(3-propanoylthio-2-methylpropanoyl)-L-prolyl-L-phenylalanine tert-butyl ester obtained was dissolved in a mixture of anisole (10 ml) and trifluoroacetic acid (20 ml). The solution was allowed to stand at room temperature for one hour and concentrated to dryness under reduced pressure. The residue was chromatographed on silica gel with chloroform-methanol (98:2) to give 1-(3-propanoylthio-2-methylpropanoyl)-L-prolyl-L-phenylalanine. The diastereomeric mixture thus obtained was dissolved in a proper amount of diethyl ether. The solution was seeded with crystals of the title compound and stored in a refrigerator. The precipitated crystals were collected and recrystallized repeatedly from diethyl ether/petroleum ether to give the title compound, m.p. 107°-114° C. [α]D20 =-81.1° (c=1.00, ethanol)

Provenance & Evidence