Benzylamine → ((3S,5S)-5-benzylcarbamoyl-1-{(S)-2-[(S)-2-(tert-butoxycarbonyl-methyl-amino)-propionylamino]-2-cyclohexyl-acetyl}-pyrrolidin-3-yl)-carbamic acid 9H-fluoren-9-ylmethyl ester

Participants

Reaction Conditions

Reaction Steps

To (2S,4S)-1-{(S)-2-[(S)-2-(tert-butoxycarbonyl-methyl-amino)-propionylamino]-2-cyclohexyl-acetyl}-4-(9H-fluoren-9-ylmethoxycarbonylamino)-pyrrolidine-2-carboxylic acid (Intermediate 27) in DMF at 0° C. was added DIPEA (116 μL, 0.66 mmol) and HATU (93 mg, 0.24 mmol). The mixture was stirred at 0° C. for 15 minutes and then benzylamine (26.1 mg, 0.24 mmol) in DMF (0.5 mL) was added dropwise, the cooling bath removed and the reaction stirred for 2 h. The mixture was diluted with water and extracted with EtOAc. The combined extracts were washed with saturated ammonium chloride solution, saturated sodium bicarbonate solution, water, and brine and dried over anhydrous magnesium sulfate. Concentration gave ((3S,5S)-5-benzylcarbamoyl-1-{(S)-2-[(S)-2-(tert-butoxycarbonyl-methyl-amino)-propionylamino]-2-cyclohexyl-acetyl}-pyrrolidin-3-yl)-carbamic acid 9H-fluoren-9-ylmethyl ester as a foam which was used without purification.

Provenance & Evidence