A mixture of commercially available 4,6-dichloropyrimidine (300 mg, 2.01 mmol), (E)-4-chlorostyrylboronic acid (441 mg, 2.41 mmol), potassium phosphate (1282 mg, 6.04 mmol), and PalladiumTetrakis (116 mg, 0.10 mmol) in DMF (1 mL) was stirred under nitrogen at 40° C. for 2 days. The reaction was filtered, diluted with CH2Cl2, washed with water, brine, dried (MgSO4), and concentrated. The crude product was purified using ISCO flash chromatography (silica gel/hexanes/ethyl acetate 100:0 to 50:50 gradient) to afford the desired product (E)-4-chloro-6-(4-chlorostyryl)pyrimidine 20A (120 mg, 0.49 mmol, 23.73% yield) as a light yellow solid. LC/MS 252 (M+H)+, tR 1.07 min (method 5).
