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A mixture of 8.3 g (0.060 mole) of 3-amino-2-pyrazinecarboxamide [prepared according to R. C. Ellingson et al., J. Am. Chem. Soc. 1945, 67, 1711], 49.5 g (0.24 mole) of triethyl orthoethoxyacetate [prepared according to S. M. McElvain and P. M. Walters, J. Am. Chem. Soc. 1942, 64, 1963] and 53 ml of acetic anhydride is refluxed under a nitrogen atmosphere for 3 hours. The temperature of this reflux falls with the passage of time from 124° to 96° C. and then remains constant at the latter temperature. After cooling, the precipitate formed is isolated by filtration. It is washed with ether and recrystallized from ethanol. Yld: 5.5 g (44%), m.p. 168°-169° C.

1. temperatureis refluxed under a nitrogen atmosphere for 3 hours
2. customfalls with the passage of time from 124° to 96° C.
3. temperatureAfter cooling
4. customthe precipitate formed
5. customis isolated by filtration
6. washIt is washed with ether
7. customrecrystallized from ethanol