Trifluoroacetic acid → (R)-1-[3-[Benzyl-[3-[(R)-2-carboxy-pyrrolidin-1-yl]-3-oxo-propyl]-amino]-propionyl]-pyrrolidine-2carboxylic acid trifluoroacetate

Participants

Reaction Steps

To a stirred solution of 200 mg (0.36 mmol) (R)-1-[3-[benzyl-[3-[(R)-2-tert-butoxycarbonyl-pyrrolidin-1-yl]-3-oxo-propyl]-amino]-propionyl]-pyrrolidine-2-carboxylic acid tert-butyl ester in 5 ml dichloromethane at 0° C. was added dropwise 1.0 ml trifluoroacetic acid and stirring continued for 16 h at room temperature. Concentration in vacuo and azeotroping three times with chloroform on a rotary evaporator afforded, after trituration in ether, 160 mg (80%) of the title compound as a yellow crystalline solid. MS m/e (%): 468 (M+Na+, 30), 446 (M+H+, 100).

Provenance & Evidence