Sodium Carbonate → rac-[(3R,4S)-4-(3,4-Dichloro-phenyl)-1-(1-propionyl-piperidine-4-carbonyl)-pyrrolidin-3-yl]-methyl-carbamic acid 4-fluoro-phenyl ester

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Reaction Steps

To a solution of rac-[(3R,4S)-4-(3,4-dichloro-phenyl)-1-(piperidine-4-carbonyl)-pyrrolidin-3-yl]-methyl-carbamic acid 4-fluoro-phenyl ester (200 mg, 0.41 mmol) in THF (2 mL) was added N,N-diisopropyl ethyl amine (208 μl, 1.21 mmol). After stirring for a period of 5 min propionyl chloride (53 μl, 0.61 mmol) was added. After stirring for 3 h at ambient temperature the reaction mixture was treated with an aqueous solution of sodium carbonate (1 M, 10 mL). The organic layer was separated and washed with brine (10 mL) and the aqueous layers were extracted with ethyl acetate (20 mL). The combined organic layers were dried over sodium sulfate and concentrated. Purification by chromatography (SiO2, ethyl acetate:methanol=100:0 to 80:20) afforded the title compound (88 mg, 40%) as a white solid. MS m/e: 550.3 [M]+.

Provenance & Evidence