2-Pyridinecarboxylic acid,3-chloro-5-(trifluoromethyl)-,methyl ester

67-56-1

338956-33-5

655235-65-7

GENERAL STEPS: Add heteroaromatic malononitrile (1.0 equiv., prepared according to Ref. 6) and the indicated solvent (1 mL / 0.12 mmol) to the reaction vessel. With stirring at room temperature, 4molecular sieves were added. A solution of anhydrous m-CPBA (1.5 eq.) was prepared by dissolving it in the indicated solvent (1 mL / 0.22 mmol) and drying over molecular sieves (4) for 10 min. The solution was added dropwise to the reaction mixture, followed by continued stirring for 10 min. After addition of nucleophilic reagent, the reaction mixture was kept stirring at room temperature. Upon completion of the reaction, the reaction was quenched with aqueous sodium thiosulfate and extracted with dichloromethane (CH2Cl2). The organic phases were combined, washed twice sequentially with saturated aqueous sodium bicarbonate (NaHCO3) and brine, dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure. Finally, purification was carried out by preparative high performance liquid chromatography (HPLC).