766-55-2

6775-78-6

766-55-2

General procedure for the synthesis of imidazo[1,2-b]pyridazine from 6-chloroimidazo[1,2-b]pyridazine: to a stirred mixed solution of 6-chloroimidazo[1,2-b]pyridazine (800 mg, 5.21 mmol) in methanol (20 mL) and tetrahydrofuran (20 mL) was sequentially added triethylamine (0.8 mL, 5.74 mmol) and Pd/C ( 100 mg, 0.094 mmol). The reaction mixture was placed under hydrogen atmosphere and stirred for 16 hours. Upon completion of the reaction, the mixture was filtered through diatomaceous earth and the diatomaceous earth bed was washed with methanol. The filtrates were combined and concentrated, and the concentrate was subsequently suspended in water and extracted with ethyl acetate (3 x 20 mL). The organic layers were combined, dried with anhydrous sodium sulfate, filtered and concentrated to give imidazo[1,2-b]pyridazine (550 mg, 87% yield) as an off-white solid. The product was analyzed by LCMS [m/z 120 (M + H)]; 1H NMR (300 MHz, DMSO-d6) δ 8.51 (dd, J = 4.53, 1.51 Hz, 1H), 8.29 (d, J = 0.76 Hz, 1H), 8.05-8.19 (m, 1H), 7.79 (d, J = 1.13 Hz, 1H), 7.22 (dd, J = 9.44, 4.53 Hz, 1H).