Diisopropylethylamine → {(3E)-4-[(1R)-1-(N-{2-[2-(2-hydroxyethoxy)phenyl]ethyl}-N-methylcarbamoyl)-2-(2-naphthyl)ethylcarbamoyl]-1,1-dimethylbut-3-enyl}carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

(2E)-5-(tert-Butoxycarbonylamino)-5-methylhex-2-enoic acid (95 mg, 0.39 mmol) was dissolved in dichloromethane (1 ml) and N,N-dimethylformamide (1 ml). 1-Hydroxy-7-azabenzotriazole (55 mg, 0,39 mmol) was added. The solution was cooled to 0° C. N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (75 mg, 0.39 mmol) was added. The reaction mixture was stirred for 20 min at 0° C. A solution of (2R)-2-amino-N-{2-[2-(2-hydroxyethoxy)pheny]ethyl}-N-methyl-3(2naphthyl)propionamide (155 mg, 0.39 mmol) in dichloromethane (1 ml) and ethyldiisopropylamine (0.07 ml, 0.39 mmol) were added successively. The reaction mixture was stirred for 16 h, while it was warming up to room temperature. It was diluted with ethyl acetate (30 ml) and washed with 10% aqueous sodium hydrogen sulfate solution (30 ml). The aqueous phase was extracted with ethyl acetate (2×20 ml). The combined organic layers were washed with a saturated aqueous solution of sodium hydrogen carbonate solution (30 ml) and dried over magnesium sulfate. The solvent was removed in vacuo. The crued product was purified by flash chromatography on silica (12 g), using ethyl acetate/heptane (2:1) as eluent to give 147 mg of {(3E)-4-[(1R)-1-(N-{2-[2-(2-hydroxyethoxy)phenyl]ethyl}-N-methylcarbamoyl)-2-(2-naphthyl)ethylcarbamoyl]-1,1-dimethylbut-3-enyl}carbamic acid tert-butyl ester.

Provenance & Evidence