反应详情

A solution of 15.6 g of camphorquinone, 7.2 g of ethylenediamine and 1 g of p-toluenesulphonic acid in 1 liter of anhydrous benzene is heated at reflux for 3 hours, 1.7 ml of water being produced. The mixture is cooled and washed with 100 ml of a 5 wt.% sodium hydroxide solution. The organic phase is decanted off and the benzene distilled off. The residue is fractionated in vacuo and there is obtained camphor-2,3-dihydropyrazine (formula I: R1 and R2 = H) with a boiling point of 90°-81°C/2.5 mm Hg. [α]D = +9.4° (ethanol). Yield 72%.

1. temperatureat reflux for 3 hours
2. temperatureThe mixture is cooled
3. washwashed with 100 ml of a 5 wt.% sodium hydroxide solution
4. customThe organic phase is decanted off
5. distillationthe benzene distilled off