Acetic Acid → HCID 20578939, compound

Participants

Reaction Steps

A solution of methyl(2S,4S)-4-[(3,3-dimethylbutanoyl)(3-methoxybenzyl)amino]tetrahydro-1H-2-pyrrolecarboxylate (19b) (138 mg, 0.38 mmol), piperonal (58 mg, 0.39 mmol) and glacial acetic acid (225 μL, 3.93 mmol) in tetrahydrofuran (2.8 mL) was stirred for 30 min at room temperature. 95% Sodium cyanoborohydride (125 mg, 1.88 mmol) was added in small portions and stirring was continued for 45 min at the same temperature. After dilution with ethyl acetate (5 mL), the reaction mixture was washed with saturated aqueous sodium hydrogencarbonate solution (2×5 mL) and brine (5 mL), dried (MgSO4) and evaporated under reduced pressure. The residue was purified by silica gel column chromatography eluting with 100% dichloromethane and dichloromethane-ethylacetate (4:1, v/v) to give the title pyrrole (20):

Provenance & Evidence