Diisopropylethylamine → (3E)-4-(N-((1R)-1-(N-((1R)-1-benzyl-2-(methylsulfonylamino)ethyl)-N-methylcarbamoyl)-2-(2-naphthyl)ethyl)-N-methylcarbamoyl)-1,1-dimethylbut-3-enylcarbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

(2E)-5-tert-Butoxycarbonylamino-5-methylhex-2-enoic acid (352 mg, 1.45 mmol) was dissolved in N,N-dimethylformamide (2 ml) and dichloromethane (2 ml). Hydroxy-7-azabenzotriazole (197 mg, 1.45 mmol) was added as a solid. The solution was cooled to 0° C. N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (278 mg, 1.45 mmol) was added. The solution was stirred for 15 min at 0° C. A solution of N-((2R)-2-(N-methyl-N-((2R)-2-methylamino-3-(2-naphthyl)propionyl)amino)-3-phenylpropyl)methanesulfonamide (598 mg, 1.32 mmol) in dichloromethane (2 ml) and ethyldiisopropylamine (0.23 ml, 1.32 mmol) were added successively. The solution was stirred for 18 h, while it was warming up to room temperature. It was diluted with ethyl acetate (100 ml) and extracted with 1 N hydrochloric acid. The aqueous phase was extracted with ethyl acetate (50 ml). The combined organic layers were washed with saturated sodium hydrogen carbonate solution (100 ml) and dried over magnesium sulfate. The solvent was removed in vacuo. The crude product was purified by flash chromatography on silica (60 g), using ethyl acetate/heptane (2:1) as eluent to give 740 mg of (3E)-4-(N-((1R)-1-(N-((1R)-1-benzyl-2-(methylsulfonylamino)ethyl)-N-methylcarbamoyl)-2-(2-naphthyl)ethyl)-N-methylcarbamoyl)-1,1-dimethylbut-3-enylcarbamic acid tert-butyl ester.

Provenance & Evidence