Triethylamine → 2-Hydroxy-5-methyl-3-[[2-[[3-(1-naphthalenyl)-2-(1-naphthalenylmethyl)-1-oxopropyl]amino]-1-oxo-6-[[(phenylmethoxy)carbonyl]amino]hexyl]amino]hexanoic acid, 1-methylethyl ester

Participants

Reaction Conditions

Reaction Steps

N-[3-(1-naphthalenyl)-2-(1-naphthalenylmethyl)-1-oxopropyl]-N6 -[(phenylmethoxy)carbonyl]-L-lysine, 4 g (6.6 mmol), 1.58 g (6.6 mmol) of [2R-(2R*,3S*)]-3-amino-2-hydroxy-5-methylhexanoic acid, 1-methylethyl ester, monohydrochloride, and 1.79 g (13.2 mmol) of 1-hydroxybenzotriazole are combined in 80 ml of dimethylformamide. The [2R-(2R*,3S*)]-3-amino-2-hydroxy-5-methylhexanoic acid, 1-methylethyl ester, monohydrochloride is neutralized with 1.4 ml (10.1 mmol) of triethylamine. The solution is cooled to -10° C. and 1.36 g (6.6 mmol) of dicyclohexylcarbodiimide is added with stirring. The reaction mixture is kept cold for 8 hours while stirring under nitrogen, allowed to warm to room temperature overnight, filtered, the filtrate concentrated and the residue partitioned between ethyl acetate and water. The organic layer is separated and extracted with saturated solution of sodium bicarbonate, dried (sodium sulfate), filtered and concentrated. The residue is flash chromatographed over silica gel 60 (230-400 mesh), eluted with hexane-ethyl acetate (2:3), the eluates collected, dissolved in diethyl ether, filtered and the filtrate concentrated to afford 4.01 g (77%) of the title compound as a white amorphous solid.

Provenance & Evidence