反应详情

To 80 ml of ethyl alcohol were added 2.35 g of 4-hydroxy-5-oxo-5,6,7,8-tetrahydroquinoline-3-carboxylic acid ethyl ester and 0.69 g of hydroxylamine hydrochloride. The resulting reaction mixture was refluxed on an oil bath for 1 hour. After the ethyl alcohol was distilled off under reduced pressure, the residue was dissolved in dilute hydrochloric acid and the resulting solution was adjusted to pH 5.8 with 10% potassium carbonate. The crystals so precipitated were separated by filtration to obtain a yield of 1.8 g of the desired compound. This compound melted (and decomposed) at 245°-247° C. (uncorrected values). Its infrared absorption spectrum (KBr tablet) had absorption peaks at 3240, 3060, 2960, 2920, 1720, 1650, 1550, and 1185 cm-1, and its n.m.r. spectrum (CF3COOH, 60Mc, TMS) had signals at δ values of 1.50 (3H, t, J=7.5 Hz), 2.0-2.6 (2H, m), 3.0-3.5 (4H, m), 4.6 (2H, q, J=7.5 Hz), and 8.95 (1H, s).

1. customThe resulting reaction mixture
2. temperaturewas refluxed on an oil bath for 1 hour
3. distillationAfter the ethyl alcohol was distilled off under reduced pressure
4. dissolutionthe residue was dissolved in dilute hydrochloric acid
5. customThe crystals so precipitated
6. customwere separated by filtration