Trifluoroacetic acid → methyl 4-({N-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]glycyl}amino)-L-phenylalaninate

Participants

Reaction Steps

To a solution of #251 (800 mg, 1.47 mmol, 1 eq.) in dichloromethane (16 mL) was added TFA (4.8 mL) at 0° C. The mixture was stirred at room temperature for 2 hours. The mixture was concentrated in vacuo. The residue was dissolved in water and filtered. The filtrate was lyophilized to afford #252 (800 mg, 97.5%) as a white solid. HPLC (Protocol Q3) [M+H+] 445.4, retention time=0.90 min.

Provenance & Evidence