反应详情

温度

40 °C

38.4 g (0.19 mol) of 2-dichloromethyl-phenyl isocyanate are allowed to run into a suspension of 135 g (0.43 mol) of Ba(OH)2 ×8H2O in 500 ml of water, at 15°-18° C. whilst stirring vigorously (with the aid of a baffle and an impeller stirrer). The mixture is stirred for a further 30-40 minutes at this temperature and about 95 ml of 10% strength hydrochloric acid are added dropwise to the reaction mixture, at 3°-5° C., until the pH is 5-6, CO2 being evolved. After the evolution of CO2 has subsided, the reaction mixture is rendered alkaline with 4 ml of 50% strength NaOH. After removing the external cooling bath, 25 g (0.25 mol) of acetylacetone are then allowed to run in dropwise in the course of 15-30 minutes and the mixture is stirred for a further 4-6 hours at room temperature. It is then filtered and the filter residue is taken up in methanol and warmed to 40° C. After cooling, the undissolved barium salt is filtered off and the filtrate is evaporated. After drying in a desiccator, 33 g (94% of theory) of 3-acetyl-3-hydroxy-quinaldine with a melting point of 54°-56° C. are obtained.

1. customdropwise in the course of 15-30 minutes
2. stirringthe mixture is stirred for a further 4-6 hours at room temperature
3. filtrationIt is then filtered
4. temperatureAfter cooling
5. filtrationthe undissolved barium salt is filtered off
6. customthe filtrate is evaporated
7. customAfter drying in a desiccator