Diisopropylethylamine → rac-{(3R,4S)-4-(3,4-Dichloro-phenyl)-1-[1-(1-methyl-cyclopropanecarbonyl)-piperidine-4-carbonyl]-pyrrolidin-3-yl}-methyl-carbamic acid tert-butyl ester

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Reaction Steps

To a solution of rac-[(3R,4S)-4-(3,4-dichloro-phenyl)-pyrrolidin-3-yl]-methyl-carbamic acid tert-butyl ester (2.78 g, 7.56 mmol) in DMF (28 mL) were added at 0° C. N,N-diisopropyl ethyl amine (8.26 mL, 48.2 mmol), 1-(1-methyl-cyclopropanecarbonyl)-piperidine-4-carboxylic acid (2.78 g, 8.04 mmol), 0-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (3.67 g, 9.65 mmol). The resulting solution was stirred for 6 h at ambient temperature. After diluting with EtOAc (50 mL) the solution was washed twice with water (50 mL) and brine (50 mL). The aqueous layers were extracted with EtOAc (50 mL) and dried over sodium sulfate. Concentration and purification by chromatography (SiO2, heptane:ethyl acetate:methanol=80:20:0 to 0:90:10) afforded the title compound (3.06 g, 75%) as a light brown foam. MS m/e: 538.3 [M+H]+.

Provenance & Evidence