Citric Acid → N-[(S)-1-[(S)-2-(3-butoxy-3-phenylazetidin-1-yl)-1-(4-methoxybenzyl)-2-oxoethylcarbamoyl]-2-(1H-imidazol-4-yl)ethyl]benzamide

Participants

Reaction Steps

1 ml of a 3/2 dichloromethane/trifluoroacetic acid solution is added to 200 mg (0.343 mmol) of (S)-2-[(S)-2-benzoylamino-3-(1H-imidazol-4-yl)propionylamino]-3-(4-methoxyphenyl)propanoic acid. After stirring at ambient temperature for 1 hour, the solvents are evaporated off. The residue obtained is dissolved in 5 ml of DMF, and 110 mg (0.343 mmol) of TBTU and 2.37 ml of DIEA are added. The reaction medium is left to stir for 15 minutes at ambient temperature. 47 mg (0.147 mmol) of 3-butoxy-3-phenylazetidine trifluoroacetate dissolved in 5 ml of a 1/4 DCM/DMF solution are added dropwise and stirred at ambient temperature for 16 hours. A 5% citric acid solution is added, followed by extraction with dichloromethane. The organic phase is washed with a saturated solution of potassium hydrogen carbonate. The organic phase is dried and evaporated to dryness. The crude product obtained is purified by silica gel chromatography (eluent 9/1 dichloromethane/methanol). 55 mg of N—[(S)-1-[(S)-2-(3-butoxy-3-phenylazetidin-1-yl)-1-(4-methoxybenzyl)-2-oxoethylcarbamoyl]-2-(1H-imidazol-4-yl)ethyl]benzamide are obtained in the form of a white powder with a yield of 60%.

Provenance & Evidence