反应详情

74.5 g (324.8 mmol) of N-carboxymethylene-4-chloroanthranilic acid are suspended in 1660 g of ethanol, 2.9 g (2.96 mmol) of concentrated sulfuric acid are added and the mixture is heated at the boiling point for 10 hours. After a reaction time of 5 hours, the same amount of sulfuric acid is again added. After 10 hours, the ethanol is distilled off and the product which precipitates out is filtered off in the cold and washed with cold ethanol. 55.5 g (0.22 mol, 73%) of N-carboethoxymethylene-4-chloro-anthranilic acid are obtained.

1. temperaturethe mixture is heated at the boiling point for 10 hours
2. distillationthe ethanol is distilled off
3. customthe product which precipitates out
4. filtrationis filtered off in the cold
5. washwashed with cold ethanol