Carbon Dioxide → 6-Chloro-8-((4-methoxybenzyl)(phenyl)amino)imidazo[1,2-b]pyridazine-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To an oven dried 25 ml shlenk flask under nitrogen was added 3-bromo-6-chloro-N-(4-methoxybenzyl)-N-phenylimidazo[1,2-b]pyridazin-8-amine (0.5 g, 1.1 mmol) from Example XXXI step (1a) and THF (5.0 ml). The solution was cooled to −78° C. and n-butyllithium was added drop-wise over 10 minutes. The reaction was allowed to stir at the depressed temperature for 1 hour. Carbon dioxide gas was then introduced via a needle purging the solution for 2 minutes. The reaction was allowed to warm to 25° C. and stir for an additional 30 minutes. Dilute 1N HCl was added taking the aqueous portion to pH=5. Ethyl acetate was added and the layers separated. The organic layer was washed with water (20 ml), then brine (10 ml), dried over Na2SO4, filtered and concentrated to provide 0.47 g of 6-chloro-8-((4-methoxybenzyl)(phenyl)amino)imidazo[1,2-b]pyridazine-3-carboxylic acid (98%). m/z=(410, M+1).

Provenance & Evidence