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

Participants

Reaction Conditions

Reaction Steps

25 g (124.8 mmol) of 2-amino-3-benzyloxypyridine were dissolved in 781 ml of ethanol, 102.7 g (624.2 mmol) of ethyl 2-chloroacetoacetate and two tablespoons of 4 A molecular sieve were added, and the reaction mixture was then heated at reflux (bath temperature 100° C.) for 2 days. The mixture was concentrated, and excess ethyl 2-chloroacetoacetate was removed on a rotary evaporator with dry ice cooling. The residue was purified by silica gel chromatography (mobile phase cyclohexane:ethyl acetate gradient 9:1, 4:1). This gave 20.81 g of the target compound (54% of theory, purity 99%).

Provenance & Evidence