Sodium Iodide → 6-Iodo-3-isopropyl-[1,2,4]triazolo[4,3-b]pyridazine

Participants

Reaction Conditions

Reaction Steps

Two reactions were set up side by side as follows. Each 250 mL round bottom flask was charged with 6-chloro-3-isopropyl-[1,2,4]triazolo[4,3-b]pyridazine (7.5 g, 38.1 mmol, Preparation #G.1), sodium iodide (8.58 g, 57.2 mmol) and hydriodic acid (57 wt % in water, stabilized with <1.5% hypophosphorous acid; 52.1 mL, 381 mmol). The mixture was heated in an oil bath to about 90° C. with stirring for about 4 days. The combined reactions were filtered then the filtrate was basified with 25 wt % aqueous NaOH. The solids from the filtration were then added to the filtrate (still basic) and extracted with DCM (750 mL). The organic phase was dried over MgSO4, filtered, and concentrated under reduced pressure. The crude product was crystallized from DMF (90 mL, about 90° C.) to give the title compound (17.3 g, 78%): LC/MS (Table 1, Method a) Rt=1.67 min; MS m/z: 289.0 (M+H)+.

Provenance & Evidence