Trifluoroacetic acid → (2S,3S)-N-(4-acetyl-thiazol-2-yl)-2-[(R)-2-amino-2-(4-methoxy-phenyl)-acetylamino]-3-phenyl-butyramide

Participants

Reaction Steps

[(R)-[(1S,2S)-1-(4-Acetyl-thiazol-2-ylcarbamoyl)-2-phenyl-propylcarbamoyl]-(4-methoxy-phenyl)-methyl]-carbamic acid tert-butyl ester (3.1 g, 5.2 mmol) was stirred in dichloromethane (50 mL) in an ice-bath. Trifluoroacetic acid (50 mL) was added and the solution was stirred for 1 hour. The reaction mixture was evaporated and the residue was precipitated with hexanes/ether. The mixture was stirred vigorously for 10 minutes and then filtered. The solid was partitioned between aqueous sodium bicarbonate and dichloromethane. The organic layer was separated and the aqueous layer extracted with dichloromethane. The combined organic extracts were washed with brine and dried (sodium sulfate). Evaporation of the solvents gave (2S,3S)-N-(4-acetyl-thiazol-2-yl)-2-[(R)-2-amino-2-(4-methoxy-phenyl)-acetylamino]-3-phenyl-butyramide (2.7 g, 90% pure) as a white solid.

Provenance & Evidence