(3R)-1-benzylpyrrolidin-3-amine → (2S)-1-(1,3-benzoxazol-2-yl)-N2-[(3R)-1-benzylpyrrolidin-3-yl]-2-piperidinecarboxamide

Participants

Reaction Steps

Triethylamine (0.167 ml) was added to a solution of (2S)-1-(1,3-benzoxazol-2-yl)-2-piperidinecarboxylic acid (100 mg) [see Preparation 3], 1-hydroxybenzotriazole hydrate (60.4 mg), (3R)-1-benzylpyrrolidin-3-ylamine (78.7 mg) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (85.4 mg) in dichloromethane (30 ml). The reaction mixture was stirred at room temperature for 18 hours, after which time the mixture was diluted with water and the organic layer was separated, dried over anhydrous sodium sulphate and the solvent removed under reduced pressure. The crude product was purified by column chromatography on silica gel eluting with a solvent gradient of 50:50:0, changing to 25:75:0, changing to 20:80:1, by volume, hexane:ethyl acetate:0.88 aqueous ammonia solution to afford (2S)-1-(1,3-benzoxazol-2-yl)-N2-[(3R)-1-benzylpyrrolidin-3-yl]-2-piperidinecarboxamide as a yellow oil (94 mg).

Provenance & Evidence