To a 100-mL round-bottomed flask was added 4,6-dichloro-2-(methylthio)pyrimidine (2.0 g, 10.25 mmol, Sigma-Aldrich) and 4-(n-boc-amino)-piperidine (2.053 g, 10.25 mmol, Sigma-Aldrich) in DCM (25 mL) followed by Et3N (2.139 mL, 15.38 mmol). The reaction was stirred at RT for 5 h, then diluted with DCM (100 mL). The mixture was washed with water, brine, dried MgSO4, filtered and concentrated to give crude tert-butyl 1-(6-chloro-2-(methylthio)pyrimidin-4-yl)piperidin-4-ylcarbamate (3.80 g, 100%) as a white solid. MS (ESI, pos. ion) m/z: 359.0 (M+1).
