反应详情

温度

50 °C

4,5-Dihydroxy-5,6,7,8-tetrahydroquinoline-3-carboxylic acid ethyl ester (4.7 g) was dissolved in 40 ml of 1 N sodium hydroxide. The resulting solution was stirred on an oil bath at 50° C. for 3 hours and then allowed to stand at room temperature overnight. After the small amount of insoluble matter was removed, the solution was adjusted to pH 2.4 with dilute hydrochloric acid. The precipitate so formed was separated by filtration to obtain a yield of 3.8 g of the desired compound. Its infrared absorption spectrum (KBr tablet) had absorption peaks at 3400, 3060, 2960, 1700, 1650, 1530, and 1510 cm-1, and its n.m.r. spectrum (CF3COOH, 60Mc, TMS) had signals at δ values of 1.8-2.6 (4H, m), 2.9-3.5 (2H, m), 5.55 (1H, bs), and 8.9-9.2 (1H, m).

1. waitto stand at room temperature overnight
2. customAfter the small amount of insoluble matter was removed
3. customThe precipitate so formed
4. customwas separated by filtration