Hydrochloric Acid → 1-(3-(1-(5,7-Difluoroquinolin-6-yl)ethyl)-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)ethanone

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Reaction Steps

The crude 6-{1-[6-(1-ethoxy-vinyl)-[1,2,4]triazolo[4,3-b]pyridazin-3-yl]-ethyl}-5,7-difluoro-quinoline obtained from the previous step was dissolved in HOAc (50 mL), 3N HCl aqueous solution (5 mL) was added. The reaction mixture was stirred at rt overnight. LC/MS showed the reaction was complete. Solvent was removed under reduced pressure. EtOAc was added, and cold 1N NaOH aqueous solution was added slowly until pH 8-9. The mixture was extracted with EtOAc, and the combined organic layers were dried over anhydrous Na2SO4, filtered, concentrated, and purified by column chromatography to afford 1.0 g (65% for two steps) of the title compound as a white solid. 1H-NMR (400 MHz, DMSO-d6) δ ppm 8.92 (dd, 1H), 8.32 (d, 1H), 8.14 (d, 1H), 7.68 (d, 1H), 7.61 (d, 1H), 7.42 (dd, 1H), 5.32 (q, 1H), 2.43 (s, 3H), 2.21 (d, 3H). LCMS (method A): [MH]+=354, tR=4.42 min.

Provenance & Evidence