Hydrochloric Acid → (S)-Cyclopentyl 4-methyl-2-(4-nitrobenzylamino)pentanoate

Participants

Reaction Steps

To a solution of cyclopentyl L-leucinate (2.00 g, 10.0 mmol) and 4-nitrobenzaldehyde (3.04 g, 20.0 mmol) in DCM (40 ml) was added glacial acetic acid (2 drops). The solution was allowed to stir at RT for 1 h whereupon sodium triacetoxyborohydride (6.40 g, 30.2 mmol) was added in a single a portion. After stirring for 3 h, the solution was poured on to aq. 1M HCl, allowed to stir for 30 min, neutralised with aq. 1M NaOH and extracted with DCM. The combined organics were washed with water and brine, dried over MgSO4, and evaporated under reduced pressure. The crude material was purified by chromatography (5% EtOAc/isohexane) to furnish the title compound as an oil (1.51 g, 45%). m/z 335.1 [M−H]+.

Provenance & Evidence