(R)-2-({(S)-1-[(R)-5-(4-cyano-benzyl)-7-(3,5-dichloro-phenyl)-5-methyl-6-oxo-6,7-dihydro-5H-imidazo[1,2-a]imidazole-3-sulfonyl]-pyrrolidine-2-carbonyl}-amino)-propionic acid → (S)-1-[(R)-5-(4-Cyano-benzyl)-7-(3,5-dichloro-phenyl)-5-methyl-6-oxo-6,7-dihydro-5H-imidazo[1,2-a]imidazole-3-sulfonyl]-pyrrolidine-2-carboxylic acid amide

Participants

Reaction Steps

To a stirred solution of (R)-5-(4-cyano-benzyl)-7-(3,5-dichloro-phenyl)-5-methyl-6-oxo-6,7-dihydro-5H-imidazo[1,2-a]imidazole-3-sulfonyl chloride (see Example 5) (50 mg, 0.10 mmol) in anhydrous methylene chloride (1 mL) was added 4-dimethylaminopyridine (DMAP) (37 mg, 0.30 mmol). L-Proline amide hydrochloride (69 mg, 0.30 mmol) was added to the mixture and the reaction was stirred for 18 h at room temperature under nitrogen. The reaction was concentrated and the residue was purified by column chromatography over silica gel (gradient elution with 35-50% EtOAc in hexanes) to provide 141 mg of (S)-1-[(R)-5-(4-Cyano-benzyl)-7-(3,5-dichloro-phenyl)-5-methyl-6-oxo-6,7-dihydro-5H-imidazo[1,2-a]imidazole-3-sulfonyl]-pyrrolidine-2-carboxylic acid amide as a white solid.

Provenance & Evidence