Heterocyclic imines and amines. Part XII. Imino-derivatives of piperazine
Sodamide in formamide effected addition of ammonia to N-benzyliminodiacetonitrile (1a) to yield 4-benzyl-2,6-di-iminopiperazine (4), which underwent displacement reactions with water and hydroxylamine, the latter giving 4-benzyl-2,6-dihydroxyiminopiperazine (5a). Similar addition of aniline and 2-aminopyridine to the dinitrile (1a) yielded the 2-imino-6-arylimino-derivatives of (4) which again gave the dioxime (5a) with hydroxylamine. N-Benzoyl-, acetyl-, and unsubstituted-iminodiacetonitrile gave the corresponding 2,6-dihydroxyiminopiperazines. Sodamide in formamide with iminodiacetonitrile provided 2,6-bisformyliminopiperazine, and with nitrilotriaceto-nitrile (10) gave 3,5-di-iminopiperazin-1-ylacetonitrile, which with hydroxylamine produced 3,5-dihydroxyimino-piperazin-1-ylacetamide oxime. The trinitrile (10) with hydroxylamine gave only the acyclic tris(amide oxime).
Spectral evidence for the iminopiperazine structures is discussed.