N-bromobutanimide → (Rac)-3-[1-(3-bromo-imidazo[1,2-a]pyridin-6-yl)-ethyl]-6-m-tolyl-imidazo[1,2-b]pyridazine

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Reaction Steps

(rac)-3-(1-Imidazo[1,2-a]pyridin-6-yl-ethyl)-6-m-tolyl-imidazo[1,2-b]pyridazine (Example 308, 100 mg, 0.283 mmol) was dissolved in DCM (2.8 mL) and NBS (50.4 mg, 0.283 mmol) was added. It was stirred at rt for 1 h then the solvent was removed. The residue was purified by flash chromatography (CombiFlash® Companion System®, with RediSep® silica gel column, 0 to 20% MeOH in DCM). Combined fractions were concentrated. The residue was repurified by preparative HPLC with acetonitrile and water (+0.1% TFA). The fractions were joined and acetonitrile was removed. The aqueous solution was basified with 5% NaHCO3 solution and was extracted with EtOAc twice. Combined organic layers was washed with brine and dried over Na2SO4. It was filtered to afford the title compound after evaporation of the solvent as a white solid. (tR 1.0 min (conditions 2), MH+=432).

Provenance & Evidence