1-Hydroxybenzotriazole → {(S)-1-cyclohexyl-2-oxo-2-[(S)-2-(3-phenoxy-phenyl)-pyrrolidine-1-yl]-ethyl}-carbamic acid tert-butyl ester

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Reaction Steps

(S)-2-(3-phenoxy-phenyl)-pyrrolidine (1.2 g, 5.02 mmol) is added to a solution of Boc-L-α-cyclohexylglycine (1.42 g, 5.2 mmol), HOBt (1.0 g, 7.53 mmol) and HBTU (2.86 g, 7.53 mmol) in 10 mL of DMF. Hunig's base (3.6 MI, 20 mmol) is added and the mixture is stirred for 30 minutes. The mixture is diluted with brine (20 mL) and extracted with EtOAc (3×10 mL). The organics were combined, dried over Na2SO4, filtered, concentrated under reduced pressures and purified by silica gel column chromatography (20% EtOAc/Hexanes) to give {(S)-1-cyclohexyl-2-oxo-2-[(S)-2-(3-phenoxy-phenyl)-pyrrolidine-1-yl]-ethyl}-cabamic acid tert-butyl ester as a white powder (1.65 g, 66%). LCMS m/z 479.2 (M+1).

Provenance & Evidence