Tert-butyl 4-(trimethylsilyloxy)-5,6-dihydropyridine-1(2H)-carboxylate (25.0 g, 0.09 mol) was used as a raw material, which was dissolved in anhydrous acetonitrile (200 mL), and 1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane ditetrafluoroborate (35.8 g, 0.101 mol) was added under stirring. The reaction mixture was stirred at room temperature for 1 hour. Upon completion of the reaction, the reaction solution was diluted with ethyl acetate and subsequently washed with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by silica gel fast column chromatography to afford tert-butyl 3-fluoro-4-oxopiperidine-1-carboxylate as an off-white solid in 73% yield (8.1 g). The product was analyzed by LCMS (Method C): m/z 118.2 (M-Boc + H), retention time 2.53 min, purity 96.5% (ELSD).1H NMR (400 MHz, DMSO-d6) δ: 4.92-4.89 (m, 1H), 4.76-4.73 (m, 1H), 4.21-4.17 (m, 1H). 3.30-3.20 (m, 2H), 2.60-2.45 (m, 2H), 1.47 (s, 9H).
![tert-Butyl 4-[(Trimethylsilanyl)oxy]-3,6-dihydro-2H-pyridine-1-carboxylate](/CAS/GIF/211108-48-4.gif)
