A solution of 5-[[(1,1-dimethylethoxy)carbonyl]amino]-2-pyridinecarboxylic acid (1 g, 4.11 mmol) in DCM (30 mL) is treated successively with 1-(3-amino-benzyl)-piperidine-4-carboxylic acid tert-butylamide (1.309 g, 4.525 mmol), EDC-HCl (1.577 g, 8.227 mmol), DMAP (75 mg, 0.62 mmol). The RM is stirred at RT for 18 h. DCM (10 mL) and aq. sat. NaHCO3 solution (30 mL) are added and the organic phase is extracted twice with DCM (2×20 mL). The combined organic layers are dried over MgSO4, filtered and evaporated. The residue is purified by flash chromatography on silica gel using a gradient of DCM/MeOH from DCM to DCM/MeOH 9:1. After concentration of the product containing fractions, the title compound (1.21 g, 58%) is obtained as a beige powder LC-MS A: tR=0.75 min; [M+H]+=510.23.
