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

Participants

Reaction Conditions

Reaction Steps

To a suspension of 49.8 g of potassium phosphate in 90 mL dimethyl sulfoxide, 30.0 g of 7-fluoro-3,4-dihydro-1,5-naphthyridin-2(1H)-one and 39.7 g of 2-bromo-1,1-dimethoxyethane were added, and the mixture was stirred at 100° C. for 3 hours. To the mixture, 7.7 g of potassium phosphate and 6.1 g of 2-bromo-1,1-dimethoxyethane were added, and the mixture was stirred for 1 hour at the same temperature. The reaction mixture was cooled to room temperature, and 120 mL of water and 120 mL of toluene were added thereto. The mixture was adjusted to pH 8.5 with acetic acid, and 3.0 g of activated carbon was added thereto. Insoluble matter was filtered out, and the filter residue was washed using 30 mL of toluene and 30 mL of water. The filtrate and the wash liquid were combined, the organic layer was separated, and the aqueous layer was extracted with 60 mL of toluene. The organic layer and the extract were combined to evaporate the solvent under reduced pressure, 90 mL of dibutyl ether was added thereto, and the mixture was cooled to −3° C. The solid product was obtained by filtration and washed using in the order of dibutyl ether and water to give 30.8 g of 1-(2,2-dimethoxyethyl)-7-fluoro-3,4-dihydro-1,5-naphthyridin-2(1H)-one as a light yellow solid.

Provenance & Evidence