848500-12-9

626-05-1

73874-95-0

848500-12-9

The reaction of 2,6-dibromopyridine (3.5 g, 14.77 mmol) and 4-tert-butoxycarbonylaminopiperidine (1.478 g, 7.38 mmol) was carried out in a sealed vessel at 130 °C for 6.5 hours, followed by warming up to 160 °C to continue the reaction for 3 hours. After completion of the reaction, the mixture was cooled to room temperature, dissolved in dichloromethane (CH2Cl2), washed sequentially with saturated sodium bicarbonate (NaHCO3) solution (twice) and brine, and the organic phase was dried with anhydrous sodium sulfate (Na2SO4), filtered and concentrated. The residue was purified by fast column chromatography (silica gel, 10-30% ethyl acetate/hexane gradient elution) to afford the intermediate (6'-bromo-3,4,5,6-tetrahydro-2H-[1,2']bipyridin-4-yl)-carbamic acid tert-butyl ester (0.83 g, 32% yield). Mass Spectra (ESI) m/z 356.0, 358.0 ([M+H]+) The intermediate was used directly in the next step of the reaction.