Acetic Acid → {4-[(S)-3-(2-Methyl-pyrrolidin-1-yl)-cyclopentyl]-phenyl}-carbamic acid benzyl ester

Participants

Reaction Steps

[4-((S)-3-Oxo-cyclopentyl)-phenyl]-carbamic acid benzyl ester (618 mg, 2 mmol, 1 equiv.) was dissolved in DCE (20 mL). To this solution was transferred a solution of 2-methylpyrrolidine (212 mg, 2.5 mmol, 1.25 equiv.) in 3 mL of DCE, followed by acetic acid (360 mg, 6 mmol, 3 equiv) in DCE (2 mL), then by addition of powder NaBH(OAc)3 (1.27 g, 6 mmol, 3 equiv.) in one portion under N2 at r.t. The yellowish milky solution was stirred at r.t. 24 h. The reaction was diluted with DCM (20 mL) and quenched with 10 mL of NaHCO3. The two layers were separated, and the aqueous layer was extracted with DCM (10 mL×2). The combined DCM extracts were washed with sodium bicarbonate (10 mL), brine (15 mL), dried (anhydrous potassium carbonate), filtered, and concentrated. The residue, a thick oil, was dissolved in DCM, and purified on a silica gel column to afford 0.61 g (81%) of the title compound.

Provenance & Evidence