Trifluoroacetic acid → HCID 86741803, compound

Participants

Reaction Steps

The product of step (b), N-(2-benzoylphenylalanylthiopropanoyl)-L-proline-t-butyl ester, 1.25 g, was suspended in 4 ml anisole and reacted with 8 ml trifluoroacetic acid for 1 hour at room temperature with stirring. In view of the fact that some starting material was later recovered, the reaction time should be increased. Trifluoroacetic acid was removed with a rotary evaporator under high vacuum. The residue was dissolved in 1 ml THF and chromatographed on a 2.2 cm×99 cm column of Sephadex LH-20 eluted with THF. Fractions of about 5.3 ml were collected. The product was eluted in fractions 41-43. The combined fractions41-43 were evaporated to dryness, dissolved in a small amount of isopropanol and rechromatographed on a 1.2 cm×95 cm LH-20 column, eluted with isopropanol. Fractions of about 2.05 ml were collected. Fractions 48-50 contained 78 mg of the desired compound as an oil. Side fractions 46-47 and 51-53 were saved for rechromatography. The oil was dissolved in a small volume of THF in a vial, then the THF was evaporated under a stream of N2. The vial was then placed in a round bottom flask connected to a rotary evaporator. After 3 hours under high vacuum, a stable, dry foam was obtained.

Provenance & Evidence