Diisopropylethylamine → 4-(5-Methanesulfonyl-pyridin-2-ylamino)-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a stirred solution of 2-bromo-5-methanesulfonyl-pyridine (0.24 g, 1.0 mmol, 1.0 equiv; prepared as described in EP 1298 116 A1 (Pfizer Products Inc., USA)) and 4-amino-piperidine-1-carboxylic acid tert-butyl ester (0.23 g, 1.1 mmol, 1.1 equiv) in acetonitrile (6.0 mL) was added N-ethyl diisopropylamine (0.87 mL, 0.66 g, 5.0 mmol, 5.0 equiv) drop by drop at rt and the reaction mixture heated to reflux for 19 h. The reaction mixture was poured into crashed ice and extracted twice with ethyl acetate. The combined organic layers were washed with brine and water, dried over MgSO4, filtered and concentrated by evaporation under reduced pressure. The crude product was purified by column chromatography on silica eluting with a gradient of dichloromethane/methanol to give 0.25 g (70%) of the title compound as light brown oil. MS (ISP): 356.1 [M+H]+.

Provenance & Evidence