Trifluoroacetic acid → N-Methyl-L-Alanyl-L-Alanine benzyl Ester

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 17 g (0.0466 mole) of Boc-N-methyl-L-alanyl-L-alanine benzyl ester in 150 ml of dry dichloromethane, cooled at -10° C., was added 100 ml trifluoroacetic acid, which was previously cooled at -10° C. The reaction mixture was stirred for 16 hours at -5° C., then poured carefully with good stirring into a mixture of 177 g of sodium bicarbonate, ice, and 150 ml of dichloromethane. The organic layer was separated and the aqueous layer was further extracted with another 60 ml of dichloromethane. The combined organic layers were washed with 3×50 ml of saturated sodium bicarbonate solution, dried over mangesium sulfate, and evaporated to give 11.6 g (91% of theory) of crude product which was used in step 3 without further purification.

Provenance & Evidence