Sodium Thiosulfate → 2-(4-Fluorophenyl)-3-iodo-6-(4-methylpiperazin-1-yl)imidazo[1,2-b]pyridazine

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Reaction Steps

To a solution, cooled to about 5° C., of 31.0 g (99.6 mmol) of 2-(4-fluorophenyl)-6-(4-methylpiperazin-1-yl)imidazo[1,2-b]pyridazine in chloroform is rapidly added dropwise a solution of 64.7 g (398 mmol) of iodine monochloride in 150 mL of methanol. Mild exothermicity and the formation of a precipitate during the addition are observed. After cooling to room temperature and stirring for 30 minutes, the mixture is poured into 2 L of aqueous 5% sodium thiosulfate solution saturated with sodium bicarbonate. After vigorous stirring until the mixture has decolorized, the product is extracted with chloroform. The organic phase is separated out, dried over sodium sulfate, filtered and concentrated under reduced pressure to give a brown solid. This solid is triturated in a mixture of 400 mL of diisopropyl ether and 50 mL of isopropanol at reflux. After cooling, 40 g of a beige-colored powder are isolated by filtration through a sinter funnel and drying under vacuum.

Provenance & Evidence