Trifluoroacetic acid → N-Methyl-L-Leucyl-L-Valyl-N-Methyl-L-Alanyl-L-Alanine Benzyl Ester

Participants

Reaction Conditions

Reaction Steps

A solution of 15.7 g (0.0266 mole) of Boc-N-methyl-L-leucyl-L-valyl-N-methyl-L-alanyl-L-alanine benzyl ester in 125 ml of dry dichloromethane was stirred and cooled to -10° C. while 70 ml trifluoroacetic acid, previously cooled at -15° C., was added. After 2 hours, the reaction was carefully added with good stirring to a mixture of 105 g of sodium bicarbonate, ice, and 200 ml of dichloromethane. The organic layer was separated and the aqueous layer was extracted with another 50 ml of dichloromethane. The combined organic layers were washed with 3×80 ml of saturated sodium bicarbonate solution, dried over magnesium sulfate, and evaporated leaving 11.85 g (91% of theory) of product. The FAB m.s. showed a molecular ion peak at 491.

Provenance & Evidence