Hydrogen Bromide → 6,8-Dimethylimidazo[1,2-b]pyridazine

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Reaction Steps

A mixture of 25 g (148 mmol) of bromoacetaldehyde dimethyl acetal, 5 mL of water and 5 mL of 48% HBr was refluxed 2 h. After cooling, it was poured into 50 mL of ethanol. Solid sodium bicarbonate was added until bubbling ceased. The mixture was filtered and to the filtrate was added 7.5 g (61 mmol) of 3-amino-4,6-dimethylpyridazine. After stirring 16 h, the ethanol was removed with a rotary evaporator. The residue was triturated with ethanol to give a brown solid which was dissolved in water and washed with dichloromethane. The aqueous layer was brought to pH 9 with sodium bicarbonate and extracted with dichloromethane. Drying (Na2SO4) and solvent removal with a rotary evaporator gave 4 g of the title compound as a brown solid, m.p. 70°-74° C.

Provenance & Evidence