反应详情

A solution of 4.0 g of n-hexyl 3,4-dihydroxy-5-nitrophenylglyoxylate and 1.5 g of diaminomaleonitrile in 35 ml of ethanol is heated to boiling under reflux for 24 hours. The alcohol is then distilled , the residue is dissolved in ether, washed with water, dried over sodium sulfate, filtered and evaporated. There is obtained 6-hydroxy-5-(3,4-dihydroxy-5-nitrophenyl)-2,3-pyrazinedicarbonitrile of m.p. >300° (from ether/methylene chloride).

1. temperatureunder reflux for 24 hours
2. distillationThe alcohol is then distilled
3. dissolutionthe residue is dissolved in ether
4. washwashed with water
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. customevaporated