Acetic Acid → 5-(3-Methoxyphenyl)-3-(5-Methyl-1,2,4-oxadiazol-3-yl)-1,6-Naphthyridin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

To a solution of acetic acid (0.90 g) in DMF (100 ml) was added N,N′-carbonyldiimidazole (2.43 g) and the mixture was stirred at 70° C. for 3 hours. To the solution was added 1,2-dihydro-5-(3-methoxyphenyl)-2-oxo-1,6-naphthyridin-3-amidoxime (3.10 g) prepared in the same manner as described in Example 1(1), and the mixture was stirred at 70° C. for 2 hours and further at 130° C. for 1 hour. The reaction mixture was concentrated to dryness under reduced pressure, and water was added to the residue, and the precipitated crystals were separated by filtration and washed with water, isopropanol and diisopropyl ether in this order and then dried. The resulting crystals were subjected to silica gel column chromatography and eluted with chloroform-methanol (50:1). The resulting crystals were recrystallized from chloroform-ethanol to give the title compound (2.22 g) as colorless crystals. M.p. 286-288° C. Hydrochloride of the title compound, M.p. 281-282° C. (recrystallized from ethanol).

Provenance & Evidence