Ammonia → Boc-(L)-Pal-NH2

Participants

Reaction Conditions

Reaction Steps

Suspend Boc-(L)-Pal-OH (1.34 g, 5 mmol) in methylene chloride (50 mL) and cool to -15° C. Add diisopropylethylamine (963 μl, 5.5 mmol) and isobutylchloroformate (715 μL, 5.5 mmol). Stir the mixture 15 minutes at -15° C. Pass through the solution a vigorous stream of anhydrous ammonia (over solid sodium hydroxide) for about 3 minutes. Stir the mixture 10 minutes at -15° C. and 20 minutes at room temperature. Evaporate methylene chloride, add ethyl acetate (70 mL) and wash with saturated aqueous solution of sodium bicarbonate. Dry over magnesium sulfate and evaporate. Crystallize from ethyl acetate/hexane to give Boc-(L)-Pal-NH2 (0.98 g, 75%).

Provenance & Evidence