Hydrochloric Acid → 4,5-Dioxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylic acid

Participants

Reaction Steps

To 25 ml of water were added 4.0 g of 4-hydroxy-5,6,7,8-tetrahydro-5-oxo-3-quinolinecarboxylic acid ethyl ester and 2.9 g of sodium hydroxide. The resulting reaction mixture was stirred at 90°-95° C. for 2 hours. After being allowed to cool, the reaction mixture was adjusted to pH 2 with 6 N hydrochloric acid. The crystals so precipitated were separated by filtration, washed with water and ethyl alcohol, and then dried at 120° C. under reduced pressure for 4 hours to obtain a yield of 3.3 g of the desired compound. This compound melted (and decomposed) at 278°-279° C. Its infrared absorption spectrum (KBr tablet) had absorption peaks at 3420, 1740, 1690, 1640, 1500, and 820 cm-1.

Provenance & Evidence