Synthesis
GENERAL STEPS: A mixture of chlorobrominated resin and K2CO3 in MeOH-H2O (8:2, 3 mL) was placed in a round-bottomed flask equipped with a magnetic stirrer. 4-Pyridinecarboxaldehyde (1 mmol, 1 equiv.) was added to it slowly and the reaction mixture was stirred at room temperature. The progress of the reaction was monitored by thin layer chromatography (TLC). After completion of the reaction, the mixture was filtered and the filtrate was extracted with ether (Et2O). The ether layer was washed sequentially with water, brine, dried with anhydrous sodium sulfate (Na2SO4), filtered and concentrated. If necessary, the residue was purified by column chromatography on silica gel (60-120 mesh) using a mixture of petroleum ether (PE) and ethyl acetate (EtOAc) (9:1) as eluent.
References
[1] Synthesis, 2010, # 2, p. 276 - 282
[2] Synlett, 2016, vol. 27, # 9, p. 1344 - 1348
[3] Tetrahedron Letters, 2014, vol. 55, # 39, p. 5358 - 5360
[4] Synthetic Communications, 2010, vol. 40, # 2, p. 186 - 195
[5] Synthesis, 2009, # 9, p. 1578 - 1581
