According to Scheme 4 Step 3: Picolinoyl chloride hydrochloride (0.93 mmol, 178 mg) and Et3N (1.86 mmol, 0.26 mL) were added to a solution of 1-(4-(4-amino-2-chlorophenyl)piperazin-1-yl)-2-methylpropan-1-one (0.62 mmol, 175 mg) in DCM (3 mL) at 0° C. The reaction mixture was stirred at room temperature for 2 hours. The organic phase was washed with a saturated solution of NaHCO3. The aqueous phase was extracted with AcOEt. The organic phase was washed with brine, was dried over Na2SO4, was filtered and was concentrated under reduced pressure. The crude product was purified by flash chromatography over C18 column using water/ACN (60:40) as eluent to afford N-(3-chloro-4-(4-isobutyrylpiperazin-1-yl)phenyl)picolinamide (0.11 mmol, 42 mg, 18%) as a white solid.
