Acrylamide (11.6 mg) was added to a solution of (2S)-1-(1,3-benzoxazol-2-yl)-N2-[(3S)-pyrrolidin-3-yl]-2-piperidinecarboxamide (51.6 mg) [see Example 4] in diethyl ether (3 ml). The reaction mixture was refluxed for 18 hours, after which time the ethereal layer was diluted with water. The aqueous layer was separated and then extracted with ethyl acetate. The combined organic layers were dried over magnesium 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 93:7:1, changing to 90:10:1, dichloromethane:methanol:0.88 aqueous ammonia solution to afford (2S)-N2-[(3S)-1-(aminocarbonylethyl)pyrrolidin-3-yl]-1-(1,3-benzoxazol-2-yl)-2-piperidinecarboxamide (26.4 mg) as an off-white foam.
