6-Amino-3-chloropyridazine → Ethyl 6-chloro-3-methylimidazo[1,2-b]pyridazine-2-carboxylate

Participants

Reaction Steps

5.83 g of 3-amino-6-chloropyridazine was suspended in 70 ml of ethanol; 9.75 g of methyl 3-bromo-2-oxobutyrate and 8.6 ml of N-ethyldiisopropylamine were added, followed by thermal refluxing for 5 hours. After cooling, the mixture was concentrated under reduced pressure; the residue was ajusted to pH 7 by the addition of an aqueous solution of sodium hydrogen carbonate and extracted with ethyl acetate-tetrahydrofuran (1:1); the extract was washed with saline and dried with magnesium sulfate. The dry product was concentrated under reduced pressure; ethyl acetate was added to the residue; the crystal precipitated was collected by filtration, washed with ethyl acetate and dried to yield 3.9 g of the title compound.

Provenance & Evidence