Lithium Hydroxide → 6-((6-bromo-1H-benzo[d][1,2,3]triazol-1-yl)methyl)imidazo[1,2-b]pyridazine-2-carboxylic acid

Participants

Reaction Steps

To a solution of ethyl 6-((6-bromo-1H-benzo[d][1,2,3]triazol-1-yl)methyl)imidazo[1,2-b]pyridazine-2-carboxylate 13A (5 g, 12.46 mmol) in 10% H2O/MeOH (200 mL), LiOH (0.597 g, 24.92 mmol) was added. The reaction was stirred at ambient temperature for 18 hrs and then concentrated to remove the MeOH. H2O (100 mL) was added and the pH was adjusted to 4 with concentrated HCl. The resulting solid was collected by filtration, rinsed with water followed by EtOAc, and dried in vacuum over P2O5 to provide the title compound, 6-((6-bromo-1H-benzo[d][1,2,3]triazol-1-yl)methyl)imidazo[1,2-b]pyridazine-2-carboxylic acid 13B (3.6 g 9.65 mmol, 77%). The filtrate was extracted with EtOAc (3×150 mL) and the organics were combined, dried with MgSO4, filtered and concentrated to dryness to give an additional 0.6 g of product. 1H NMR (400 MHz, DMSO-d6) δ ppm 6.24 (s, 2 H) 7.24 (d, J=9.35 Hz, 1 H) 7.58 (dd, J=8.84, 1.77 Hz, 1 H) 8.04-8.14 (m, 2H) 8.32 (d, J=1.01 Hz, 1 H) 8.47 (s, 1 H). MS:m/z 373.2 (M+H)+.

Provenance & Evidence