Triisopropyl borate → (6-(Butylamino)imidazo[1,2-b]pyridazin-3-yl)boronic acid

Participants

Reaction Conditions

Reaction Steps

A precooled (−78° C.) solution of 3-bromo-N-butylimidazo[1,2-b]pyridazin-6-amine (200 mg, 0.74 mmol) and tetrahydrofuran (4 mL) was treated dropwise with n-butyllithium (1.2 mL, 1.6 M, 1.9 mmol). The resulting reaction mixture was maintained at −78° C. for 5 min, then treated dropwise with tris(isopropyl)borate (0.21 mL, 0.89 mmol) and maintained at −78° C. for 2.5 h. The reaction was quenched with H2O (1 mL) and allowed to warm to RT. The organic volatiles were removed under reduced pressure, and the aqueous layer was acidified with 1 N HCl until a white precipitate formed. The solid was collected by filtration to afford (6-(butylamino)imidazo[1,2-b]pyridazin-3-yl)boronic acid (100 mg, 58%) as a white solid: 1H NMR (400 MHz, METHANOL-d4) δ ppm 7.56 (d, J=9.9 Hz, 1H), 7.39 (s, 1H), 6.66 (d, J=9.9 Hz, 1H), 3.25-3.35 (m, 2H), 1.60-1.75 (m, 1H), 1.37-1.58 (m, 1H), 0.94-1.08 (m, 1H); LCMS (ESI) m/e 235.2 [(M+H)+, calcd for C10H15BN4O2 235.1].

Provenance & Evidence