Lithium Hydroxide → 6-((6-Bromo-[1,2,4]triazolo[4,3-a]pyridin-3-yl)difluoromethyl)imidazo[1,2-b]pyridazine-2-carboxylic acid

Participants

Reaction Steps

A solution of 3.methyl 6-((6-bromo-[1,2,4]triazolo[4,3-a]pyridin-3-yl)difluoromethyl)imidazo[1,2-b]pyridazine-2-carboxylate (4.0 g, 9.45 mmol) and LiOH (0.340 g, 14.18 mmol) in 10% H2O/MeOH (150 mL) was stirred at ambient temperature for 4 hrs. Solvent was removed via rotary evaporation, and the resulting residue was diluted with H2O (100 mL). The aqueous phase was adjusted to pH=5 with concentrated HCl. The resulting precipitate was collected, rinsed with water, rinsed with EtOAc, and dried under vacuum over P2O5 for 18 hrs to provide the title compound, 6-((6-bromo-[1,2,4]triazolo[4,3-a]pyridin-3-yl)difluoromethyl)imidazo[1,2-b]pyridazine-2-carboxylic acid 45J (3.5 g, 8.55 mmol, 90%). 1H NMR (400 MHz, DMSO-d6) δ ppm 7.76 (dd, J=9.85, 1.77 Hz, 1 H) 7.82 (d, J=9.60 Hz, 1H) 8.02 (d, J=9.60 Hz, 1 H) 8.51 (d, J=9.85 Hz, 1 H) 8.90 (s, 1 H) 8.97 (s,1 H). ESI-MS:m/z 4.09 (M+H)+.

Provenance & Evidence