Diisopropylethylamine → Ethyl 6-fluoroquinoline-3-carboxylate

Participants

Reaction Steps

A solution of 4-chloro-6-fluoro-quinoline-3-carboxylic acid ethyl ester (4.2 g, 16.6 mmol) and diisopropylethylamine (8.7 mL, 50 mmol) in ethanol (50 mL) was hydrogenated over 10% palladium on carbon (0.2 g) at 1 atmosphere of hydrogen for 1 day. Additional catalyst (0.3 g) was added and the hydrogenation was continued at 50 psi of hydrogen for 2 hours. The catalyst was removed by filtration. The solvent was evaporated in vacuo, and the residue was partitioned between water and dichloromethane. The organic layer was dried over sodium sulfate. The product was preabsorbed onto silica gel and purified by flash chromatography, using a gradient of ethyl acetate (0% to 30%) in heptanes as the eluant, to give the product as a yellow solid, 2.2 g (60%). MS: m/z 219.9 (MH+).

Provenance & Evidence