反应详情

Into 40 ml of 20% aqueous solution of sulfuric acid was dissolved 20 g of N,N-dimethylaniline. To the solution were added 8.4 g of pyruvic acid and 0.2 g of p-toluenesulfonic acid and the mixture was heated with reflux for 24 hours. The reaction mixture was, after cooled, diluted with 200 ml of water and adjusted to pH 6 with addition of 20% aqueous solution of sodium hydroxide. The precipitated crystal was collected by filtration which was 18.0 g (yield 70%) of 2,2-bis(4-dimethylaminophenyl)propionic acid, having a melting point of 152°~154° C.

1. temperaturethe mixture was heated
2. temperaturewith reflux for 24 hours
3. temperatureafter cooled
4. filtrationThe precipitated crystal was collected by filtration which