Triethylamine → 2-(4-but-2-ynyloxy-benzenesulfonylamino)-3-(1-cyclobutylmethyl-1H-indol-3-yl)-propionic acid

Participants

Reaction Steps

Triethylamine (0.275 mL, 1.97 mmol) was added to a solution of crude 1-cyclobutylmethyl-D-tryptophan of Step 2 (0.657 mmol) and 4-but-2-ynyloxy-benzenesulfonyl chloride (0.177 g, 0.723 mmol) in H2O-dioxane (2 mL:3 mL) at room temperature. The reaction mixture was stirred for 20 hours at room temperature. The mixture was then concentrated and acidified with HCl. The mixture was extracted with ethyl acetate (3×10 mL). The organic solution was washed with H2O and brine, dried over Na2SO4, and concentrated. The residue was purified by RP-HPLC to give 0.152 g (48% in 3 steps) of the title compound as a yellow solid. 1H NMR (DMSO-d6): 400 MHz δ 12.57 (bs, 1H), 8.07 (d, J=8.4 Hz, 1H), 7.49 (d, J=7.2 Hz, 2H), 7.37 (d, J=8.0 Hz, 1H), 7.29 (d, J=7.6 Hz, 1H), 7.08 (t, J=7.4 Hz, 1H), 7.02 (s, 1H), 6.96-6.88 (m, 3H), 4.77 (q, J=2.4 Hz, 2H), 4.04 (d, J=6.8 Hz, 2H), 3.84 (q, J=6.8 Hz, 1H), 3.02 (dd J=14.4, 6.4 Hz, 1H), 2.82 (dd J=14.4, 8.4 Hz, 1H), 2.67 (p, J=7.6 Hz, 1H), 1.91 (m, 2H), 1.83 (m, 5H), 1.75 (m, 2H); HRMS: calcd for C26H29N2O5S (ESI+, [M+H]1+), 481.1792; found 481.1786; LCMS m/z (ESI) [M+H] 481, retention time=3.22 min.

Provenance & Evidence