Diisopropylethylamine → ((3E)-1,1-dimethyl-5-((2R)-4-((1R)-1-(methylcarbamoyl)-2-phenylethyl)-2-((2-naphthyl)methyl)-5-oxopiperazin-1-yl)-5-oxopent-3-enyl)carbamic acid tert-butyl ester

Participants

Reaction Steps

(2E)-5-Methyl-5-(tert-butyloxycarbonylamino)hex-2-enoic acid was dissolved in methylene chloride (10 ml). 1-Hydroxy-7-azabenzotriazol (60 mg, 0.46 mmol) and N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (100 mg, 0.51 mmol) were added and the mixture was stirred for 15 min. (2R)-N-Methyl-2-((5R)-5-((2-naphthyl)methyl)-2-oxopiperazin-1-yl)-3-phenylpropionamide (185 mg, 0.46 mmol) and diisopropylethylamine (0.08 ml) were added and the mixture was stirred overnight. Water (10 ml) and methylene chloride (10 ml) were added and the mixture was washed with an aqueous solution of sodium hydrogen sulphate (10%, 20 ml), a saturated aqueous solution of sodium hydrogen carbonate (20 ml), dried (magnesium sulfate) and the solvent was removed in vacuo. The residue was chromatographed on silica (3×30 cm) using ethyl acetate/heptane (1:1) as eluent to afford 0.20 g of ((3E)-1,1-dimethyl-5-((2R)-4-((1R)-1-(methylcarbamoyl)-2-phenylethyl)-2-((2-naphthyl)methyl)-5-oxopiperazin-1-yl)-5-oxopent-3-enyl)carbamic acid tert-butyl ester.

Provenance & Evidence