Citric Acid → (S)-1-(1-(5-chloropyridin-2-yl)-1-(3-fluoro-5-(trifluoromethyl)phenyl)-2-(4-methylthiazol-2-yl)ethyl)-3-cyclopentylurea

Participants

Reaction Steps

(S)-N-((S)-1-(5-chloropyridin-2-yl)-1-(3-fluoro-5-(trifluoromethyl)phenyl)-2-(4-methylthiazol-2-yl)ethyl)-2-methylpropane-2-sulfinamide (29 mg, 0.058 mmol) in MeOH (1.0 mL) was added HCl (0.5 mL, 2 mmol, 4N solution in dioxane) and the reaction was stirred at room temperature for 0.5 h. The mixture was concentrated, diluted with EtOAc (20 mL), washed with sat. NaHCO3 (20 mL), dried over Na2SO4, filtered and concentrated. The residue was dissolved in DCM (1 mL) and cyclopentyl isocyanate (9 mg, 0.083 mmol) was added followed by two crystals of citric acid. The reaction was stirred overnight, concentrated and purified by Prep TLC (Uniplate, Silica Gel GF, 20×20 cm, 1000 Microns) using Hexane/EtOAc (1/1) to yield (S)-1-(1-(5-chloropyridin-2-yl)-1-(3-fluoro-5-(trifluoromethyl)phenyl)-2-(4-methylthiazol-2-yl)ethyl)-3 -cyclopentylurea as a clear oil (10 mg, 70% yield) LCMS: 1.91 min [M+1] 527.2 (2 min gradient, MeOH/H2O 0.1% TFA); HPLC: 3.91 min (4 min gradient, MeOH/H2O 0.2% PPA); Purity 100%; NMR: 400 MHz 1H (CDCl3) 8.29 ppm, 1 H, d, J=2.64 Hz; 7.54 ppm, 1 H, dd, J=8.57, 2.42 Hz; 7.40 ppm, 1 H, s; 7.32 ppm, 1 H, s; 7.26 ppm, 1 H, d, J=9.67 Hz; 7.12 ppm, 2 H, d, J=8.35 Hz; 6.60 ppm, 1 H, s; 4.58 ppm, 1 H, d, J=13.62 Hz; 4.43 ppm, 1 H, d, J=7.03 Hz; 4.08 ppm, 1 H, d, J=13.62 Hz; 3.92 ppm, 1 H, m; 2.20 ppm, 3 H, s; 1.93 ppm, 2 H, m; 1.61 ppm, 2 H, m; 1.53 ppm, 2 H, m; 1.40 ppm, 1 H, m; 1.32 ppm, 1 H, dd, J=13.18, 7.03 Hz.

Provenance & Evidence