Addition of one of the amide amines to the nitrile would then afford the iminonitrile 5. The observed product 6 can be rationalized by assuming loss of the carboxamide under strongly basic conditions. Decarboxylative hydrolysis of 6 then leads to bemegride 7.
The introduction of an amide amine to a nitrile would lead to the formation of iminonitrile 5. The resulting product 6 can be understood as arising from the removal of the carboxamide under highly basic conditions. Subsequent hydrolysis of 6 leads to the production of bemegride 7.