Potassium Phosphate, Tribasic → 6-Chloro-3,8-bis(4-methylpyridin-3-yl)imidazo[1,2-b]pyridazine

Participants

Reaction Steps

A microwave vial was charged with a mixture of 3,8-dibromo-6-chloroimidazo[1,2-b]pyridazine (210 mg, 0.674 mmol), 4-methylpyridin-3-ylboronic acid (184 mg, 1.35 mmol), tetrakis(triphenylphosphine)palladium(0) (78 mg, 0.067 mmol), dioxane (6 mL), and K3PO4 (1 mL, 2.023 mmol) was stirred at room temperature for 5 min. under nitrogen. The resulting mixture was heated to 100° C. for 8 h in microwave. The reaction mixture was cooled to room temperature, quenched with water, and diluted with EtOAc. The layers were separated and the aqueous layer was extracted with EtOAc (3×20 mL). The combined organic layers were washed with brine, dried over anhydrous Na2SO4, and filtered. The filtrate was concentrated under reduced pressure. The residue was purified by prep. HPLC to give 56 mg (24%) product. 1H NMR (400 MHz, CD3OD) δ ppm 9.06 (1H, s), 8.93 (1H, s), 8.81 (2H, dd, J=15.23, 5.92 Hz), 8.17 (1H, s), 7.96-8.13 (2H, m), 7.68 (1H, s), 2.65 (3H, s), 2.58 (3H, s); LC/MS: Rt=0.88 min. LC/MS (Condition A): 336.14/338.15.

Provenance & Evidence