A.
α,α'-Dicyano-β-methylglutaramide. In a
6-l. flask,
520 g. (6.2 moles) of recrystallized cyanoacetamide (Note
1) is dissolved in 3.4 l. of water, and the solution is cooled to 10° and filtered if it is not clear (Note
2). While the flask is shaken constantly,
137.5 g. (3.1 moles) of freshly distilled acetaldehyde and
20 ml. of piperidine are added
successively to the solution. After the mixture has stood at room temperature for 2 hours, the flask is transferred to an
ice-salt bath and the mixture is partially frozen. During this operation, the flask should be shaken frequently. After 30 minutes,
α,α'-dicyano-β-methylglutaramide begins to deposit, and when the precipitation is complete (about 1 hour), the mixture is allowed to come to room temperature in order to melt the ice that is present. The precipitate is then filtered with suction and washed thoroughly with cold distilled water. The yield is
420–425 g. (
71%) of a white, powdery solid which melts at
152–157° (Note
3).