Hydrochloric Acid → 3-Cyclopentyl-N-[1-(2-hydroxy-ethyl)-1H-pyrazol-3-yl]-2-(R)-(4-methanesulfonyl-phenyl)-propionamide

Participants

Reaction Conditions

Reaction Steps

N-{1-[2-(tert-Butyl-dimethyl-silanyloxy)-ethyl]-1H-pyrazol-3-yl}-3-cyclopentyl-2-(R)-(4-methanesulfonyl-phenyl)-propionamide (135 mg, 0.26 mmol) was dissolved in ethanol (5 mL) and concentrated aqueous hydrochloric acid (100 μL) was added. The reaction stirred at 25° C. for 90 min. The reaction was diluted with ethyl acetate (50 mL), washed with water (20 mL), saturated aqueous brine solution (20 mL), dried over magnesium sulfate and concentrated in vacuo to give a beige foam. The foam was dissolved in methylene chloride (4 mL) and hexanes (4 mL) were added to crystallize the desired product. Collection by filtration followed by rinsing with excess hexanes afforded 3-cyclopentyl-N-[1-(2-hydroxy-ethyl)-1H-pyrazol-3-yl]-2-(R)-(4-methanesulfonyl-phenyl)-propionamide (830 mg, 78%) as colorless crystals: ESI-LRMS m/e calcd for C20H27N3O4S [M+] 405.17, found 406.35 [M+H+]; 1H NMR (400 MHz, DMSO-d6) δ ppm 1.05-1.21 (m, 2H, CH2), 1.38-1.82 (m, 8H, 4×CH2), 2.01-2.23 (m, 1H, CH), 3.17 (s, 3H, SO2CH3), 3.66 (q, J=5.5 Hz, 2H, OCH2), 3.89-3.95 (m, 1H, CH), 3.98 (t, J=5.5 Hz, 2H, NCH2), 4.80 (t, J=5.5 Hz, 1H, OH), 6.40 (d, Jo=2.2 Hz, 1H, Ar), 7.51 (d, Jo=2.2 Hz, 1H, Ar), 7.62 (d, Jo=8.5 Hz, 2H, Ar), 7.85 (d, Jo=8.5 Hz, 2H, Ar), 10.70 (s, 1H, NH).

Provenance & Evidence