1,3-Propanediamine, N'-(ethylcarbonimidoyl)-N,N-dimethyl-, monohydrochloride → (1R)-1-methyl-2-phenylcarbonyloxyethyl (2S)-2-[(tert-butoxy)carbonylamino]-3-[3,4-bis(phenylmethoxy)phenyl]propanoate

Participants

Reaction Steps

To a solution of (2S)-2-[(tert-butoxy)carbonylamino]-3-[3,4-bis(phenylmethoxy)phenyl]propanoic acid (15.9 g, 33.3 mmol), (2R)-2-hydroxypropyl benzoate (5.0 g, 27.7 mmol), and 4-(dimethylamino)pyridine (340 mg) in 250 mL of anhydrous dichloromethane, 1-(3-dimethylaminopropyl)3-ethylcarbodiimide hydrochloride (EDAC) (8.0 g, 41.6 mmol) was slowly added. The resulting mixture was stirred at room temperature for 16 hrs. The reaction mixture was diluted with dichloromethane and washed with 0.5N HCl twice, followed by the addition of brine. The organic layer was separated, dried through a MgSO4 pad and concentrated under reduced pressure. Chromatography (silica gel, 1:5 then 1:4 ethyl acetate/hexane) of the residue followed by crystallization from 1:5 ethyl acetate/hexane afforded 8.0 g (45%) of the title compound.

Provenance & Evidence