反应详情

A 50 ml. flask was charged with 0.90 g. pyrazine-2,3-dicarboxamide dissolved in 16 ml. dimethylformamide. A 2.4 g. portion of lead tetra-acetate was added to the solution and the reaction mixture was stirred at 40° for 15 minutes. The reaction mixture was cooled, 30 g. of ice was added and after 1 hour the mixture was filtered. Crystallization of the residue from water gave, after drying in vacuo, a yield of 0.64 g. of pyrazino[2,3-d]pyrimidine-2,4(1H,3H)-dione, melting point 364°-365°, which represented 71 percent of theory. The structure was confirmed by infra-red spectroscopy.

1. additionflask was charged with 0.90 g
2. temperatureThe reaction mixture was cooled
3. additionof ice was added and after 1 hour the mixture
4. filtrationwas filtered
5. customCrystallization of the residue from water
6. customgave
7. customafter drying in vacuo