General procedure for the synthesis of 4-(tert-butyl)-2-chloropyridine from 4-tert-butylpyridine 1-oxide: 4-tert-butylpyridine 1-oxide (5 g, 33.07 mmol) was placed in a two-necked flask. The double-necked flask was cooled in an ice bath and 25 ml of phosphoryl chloride (POCl3) was slowly added to the double-necked flask to form a reaction mixture. The mixture was heated under reflux conditions for 24 hours to complete the reaction. After completion of the reaction, the temperature was slowly reduced to 20°C and the solvent was removed by distillation under reduced pressure. The reaction mixture was neutralized by adding aqueous sodium carbonate solution to a two-necked flask, followed by extraction of the reaction mixture with ethyl acetate and collection of the organic layer. The organic layer was dried over anhydrous sodium sulfate (Na2SO4) to give the crude product. The crude product was purified by column chromatography (silica gel as stationary phase, eluent ratio of ethyl acetate: n-hexane = 1:6) to give 4-(tert-butyl)-2-chloropyridine (4 g, 72% yield) as a clear liquid. The structure of the compound was confirmed by 1H-NMR (400 MHz, CDCl3): δ8.27 (d, J=5.3 Hz, 1H), 7.28 (s, 1H), 7.19 (dd, J=5.2 Hz, 1.6 Hz, 1H), 1.29 (s, 9H).
