Ethyl 2-chloroacetoacetate → Ethyl 6-chloro-8-[(2,6-difluorobenzyl)oxy]-2-methylimidazo[1,2-a]pyridine-3-carboxylate

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Reaction Steps

40 g of 5-chloro-3-[(2,6-difluorobenzyl)oxy]pyridine-2-amine (Example 17A; 147.8 mmol; 1 equivalent) were initially charged in 800 ml of ethanol, 30 g of powdered molecular sieve 3 Å and 128 g of ethyl 2-chloroacetoacetate (739 mmol, 5 equivalents) were added and the mixture was heated at reflux overnight. The reaction mixture was concentrated and the residue was taken up in ethyl acetate and filtered. The ethyl acetate phase was washed with water, dried, filtered and concentrated. This gave 44 g (78% of theory) of the title compound.

Provenance & Evidence