Nitrolysis of 1, 3, 5-trisW-cyanoethyl) hexahydro-s-triazine (I) has been studied in nitric acid- acetic anhydride medium, when a mixture of N-acetoxymethyl-3-nitraminopropionitrile (Ill) and 4, 6-dinitro-4, 6-diazanonanedioic acid dinitrile (IX) is formed predominantly. Ratio of the both main reaction products 111 and 1 X is markedly affected especially by acidity of the reaction medium. Yields of the dinitrile IX can positively be influenced by the presence of ...