3-{3-[2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionylamino]-pyrazol-1-yl}-propionic acid tert-butyl ester → 3-{3-[2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionylamino]-pyrazol-1-yl}-propionic acid

Participants

Reaction Conditions

Reaction Steps

3-{3-[2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionylamino]-pyrazol-1-yl}-propionic acid tert-butyl ester (prepared in example 8, 3.00 g, 5.72 mmol) was dissolved in 20% trifluoroacetic acid/methylene chloride (100 mL) and stirred under reflux at 60° C. for 2 h, after which time the solvent was removed in vacuo. The crude material was the purified by ISCO flash column chromatography (Teledyne Isco RediSep Flash Column 120 g; 0% ethyl acetate/hexanes to 75% ethyl acetate/hexanes) to afford 3-{3-[2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionylamino]-pyrazol-1-yl}-propionic acid (2.60 g, 97%) as a white solid: ESI-LRMS m/e calcd for C21H26ClN3O5S [M+] 509.18, found 510.0 [M+H+], 1019.7 [2M+H+]; 1H NMR (400 MHz, CDCl3) δ ppm 1.06-1.23 (m, 2H, CH2), 1.42-1.91 (m, 8H, 4×CH2), 2.12-2.29 (m, 1H, CH), 2.83 (t, J=6.4 Hz, 2H, COCH2), 3.25 (s, 3H, SO2CH3), 3.57 (t, J=7.5 Hz, 1H, CH), 4.36 (t, J=6.4 Hz, 2H, NCH2), 6.77 (d, J=2.5 Hz, 1H, Ar), 7.41 (d, J=2.5 Hz, 1 H, Ar), 7.48 (dd, Jo=8.1, Jm=1.5 Hz. 1H, Ar), 7.62 (d, Jm=1.5 Hz, 1H, Ar), 8.06 (d, Jo=8.1 Hz, 1H, Ar), 9.85 (br.s., 1H, CO2H), 10.38 (s, 1H, NH).

Provenance & Evidence