Hydrochloric Acid → HCID 59699551, compound

Participants

Reaction Steps

Diethyl malonate (2.37 mL, 15.61 mmol) was added slowly to a suspension of NaH (60% in mineral oil, 0.62 g, 15.61 mmol) in dimethylacetamide (40 mL) and stirred at room temperature for 0.5 h under inert atmosphere. 1-(4-Methoxy-benzyl)-1H-pyrido[2,3-d][1,3]oxazine-2,4-dione (12) (4.47 g, 15.61 mmol) was added to the solution and heated at 110° C. for 3 h (TLC control). The solution was cooled and poured into ice water. The pH of the solution was adjusted to 3 by cold 10% HCl. The solids formed were filtered, washed by excess water, and dried in a vacuum oven. The crude product was recrystallized by ethylacetate to yield 1.2 g (21%) of 4-hydroxy-1-(4-methoxy-benzyl)-2-oxo-1,2-dihydro-[1,8]-naphthyridine-3-carboxylic acid ethyl ester (13) as white solids. MP: 153° C.; 1H-NMR (DMSO-d6): δ 1.31 (t, J=7.0 Hz, 3H), 3.68 (s, 3H), 4.32 (q, J=7.0 Hz, 2H), 5.47 (s, 2H), 6.81 (d, J=7.7 Hz, 2H), 7.21 (d, J=7.6 Hz, 2H), 7.36 (d, J=7.6 Hz, 1H), 8.42 (dd, J=1.5, 7.5 Hz, 1H), 8.73 (dd, J=1.5, 7.5 Hz, 1H), 13.00 (S, 1H); EIMS: 355 (M+1).

Provenance & Evidence