Ethyl 2-chloroacetoacetate → Ethyl 8-(benzyloxy)-6-bromo-2-methylimidazo[1,2-a]pyridine-3-carboxylate

Participants

Reaction Steps

Under argon, 200 g (0.72 mol) of 3-(benzyloxy)-5-bromopyridine-2-amine, 590 g (3.58 mol) of ethyl 2-chloroacetoacetate and 436 g of 3 Å molecular sieve were suspended in 6 l of ethanol and stirred at reflux for 72 h. The reaction mixture was filtered off through silica gel and concentrated. The residue was purified by silica gel chromatography (petroleum ether:ethyl acetate 9:1, then 6:4) and the product fractions were concentrated. This gave 221 g (79% of theory) of the target compound.

Provenance & Evidence