14222-60-7

80944-48-5

14222-60-7

GENERAL METHODS: To a reaction flask containing pyridine-4-carboxamide derivatives (1 eq.) was added tetrahydrofuran (THF, 5 mL/millimole) at room temperature and protected by argon and mixed with stirring. Subsequently, Lawesson's reagent (1.5 eq.) was added to the reaction system and the reaction was continuously stirred at room temperature for 48 to 72 hours. Upon completion of the reaction, the THF solvent was removed by distillation under reduced pressure. The residue was extracted by partitioning with saturated aqueous sodium bicarbonate (25 mL) and ethyl acetate (25 mL), and the extraction was repeated with ethyl acetate (2 x 25 mL). The organic phases were combined and dried with anhydrous magnesium sulfate (MgSO4) and subsequently concentrated under vacuum. Finally, the product was further purified by fast column chromatography (elution gradient: 0-3% methanol/dichloromethane, using a puriFlash 15-SI-HC 25G column, elution time 45 min).