Diisopropylethylamine → (S)-tert-butyl 3-(benzyloxycarbonylamino)-2-oxo-1,4'-bipiperidine-1'-carboxylate

Participants

Reaction Conditions

Reaction Steps

Crude (S)-2-(benzyloxycarbonylamino)-5-(1-(tert-butoxycarbonyl)piperidin-4-ylamino)pentanoic acid (84 g, 187 mmol) was dissolved in DMF (600 mL), and cooled to 0° C. N1-((ethylimino)methylene)-N3,N3-dimethylpropane-1,3-diamine hydrochloride (35.8 g, 187 mmol) and N-ethyl-N-isopropylpropan-2-amine (32.5 mL, 187 mmol) were added and the reaction stirred at ambient temperature overnight. The reaction was concentrated and dissolved in EtOAc (1000 mL), washed with 1N HCl, saturated aqueous NaHCO3 and brine, dried over Na2SO4, filtered and concentrated. The residue was purified over silica gel (50% EtOAc in hexanes) to afford (S)-tert-butyl 3-(benzyloxycarbonylamino)-2-oxo-1,4′-bipiperidine-1′-carboxylate (49 g, 114 mmol, 60.8% yield) as white solid.

Provenance & Evidence