A 2% solution of HCl in MeOH was prepared by adding acetyl chloride (1.1 mL) to MeOH (25 mL). To this solution was added 1-[(tert-butoxy)carbonyl]-4-methoxypiperidine-4-carboxylic acid (1 g, 3.6637 mmol) and the solution was heated under reflux for 6 h. The reaction mixture was evaporated to dryness and left on a vacuum line for 30 minutes. The material thus obtained was dissolved in ethanol (8 mL) and stirred with sodium carbonate (0.96 g, 9.1 mmol) for 10 minutes, then (2-chloropyrimidin-5-yl)-boronic acid (0.57 g, 3.61 mmol) was added and the mixture was stirred at 60° C. for 6 h. The reaction mixture was filtered through celite and the solvents removed in vacuo to give the title compound (0.8 g, 71%) as a white foam, which was used without further purification. LCMS (pH 10) MH+ 296, RT 0.86 minutes.
