Triethylamine → 7-fluoro-3,4-dihydro-1,5-naphthyridin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

To a suspension of 9.1 g of butyl (2E)-3-(3-amino-5-fluoropyridin-2-yl)acrylate and 0.9 g of 10% palladium carbon in 30 mL of methanol, 4 mL of formic acid was added, and 15 mL of triethylamine was added dropwise thereto under ice cooling. The reaction mixture was stirred at 60° C. for 2 hours. The reaction mixture was cooled to room temperature, insoluble matter was filtered out, and the filter residue was washed using 30 mL of toluene. The filtrate and the wash liquid were combined and the solvent was evaporated under reduced pressure. To the obtained residue, 30 mL of toluene was added, the mixture was stirred at 100° C. for 2 hours and 30 minutes. To the reaction mixture, 30 mL of water was added dropwise at 45° C. and the mixture was cooled to 5° C. The solid product was obtained by filtration and washed in the order of water and toluene to give 5.7 g of 7-fluoro-3,4-dihydro-1,5-naphthyridin-2(1H)-one as a white solid.

Provenance & Evidence