Trifluoroacetic acid → 3-(3-{1-[2-(2-Amino-propionylamino)-3-methyl-butyryl]-pyrrolidin-2-ylmethyl}-benzofuran-2-yl)-propionic acid ethyl ester

Participants

Reaction Steps

To a solution of 51 (160 mg, 0.28 mmol) in DCM (10 mL) was added TFA (2 mL) at ambient temperature. After 2.5 h, the solvent was removed under reduced pressure. The residue was dissolved in EtOAc and washed with aqueous NaHCO3, brine, dried over anhydrous Na2SO4, filtered and concentrated. A portion (˜50%) of the crude material was purified by reverse-phase HPLC (C18, 10-100% ACN/water containing 0.1% HOAc) to afford 56 mg of 52 as a white solid. 1H NMR (DMSO, 300 MHz) 58.03 (d, J=8.7 Hz, 1H), 7.77 (m, 1H), 7.43-7.41 (m, 1H), 7.21 (m, 2H), 4.37 (app t, J=8.1 Hz, 1H), 4.19 (m, 1H), 4.01 (q, J=7.2 Hz, 2H), 3.65 (m, 1H), 3.56 (app d, J=6.6 Hz, 1H), 3.28 (m, 1H), 3.06-3.01 (m, 3H), 2.68 (app t, J=7.2 Hz, 2H), 2.07-1.96 (m, 1H), 1.63 (m, 1H), 1.54 (m, 1H), 1.13-1.09 (m, 6H), 0.90 (d, J=6.3 Hz, 3H), 0.85 (d, J=6.3 Hz, 3H) ppm. Mass spectrum: m/z 472 [M+H]+; and, 494 [M+Na]+.

Provenance & Evidence