Abstract

The reaction of 2,3,5,6-tetrahydroxypiperazine-1,4-dicarbaldehyde (1) with guanidine hydrochloride in hydrochloric acid can be controlled to give 2,6-diiminododecahydrodiimidazo[4,5-b:4′,5′-e] pyrazine (2a) or the cis isomer of 4,5-diamino-2-iminoimidazolidine (4). Compound (4) reacts with formaldehyde, or formic acid followed by reduction, to give 2-iminooctahydroimidazo[4,5-d] imidazole (7). Treatment of (2a) or (7) with nitric acid gives dinitro derivatives that were isolated as nitric acid salts of the cyclic guanidines. Reaction of the dinitro derivatives with nitric acid/acetic anhydride in the presence of chloride ion gives 4,8-dinitro-2,6-bis( nitroimino ) dodecahydrodiimidazo -[4,5-b:4′,5′-e] pyrazine (3a) and 1,3-dinitro-5-( nitroimino ) octahydroimidazo [4,5-d] imidazole (9). The reaction of (7) with nitric acid/ trifluoroacetic anhydride was controlled to give either the tetranitro or a dinitro bis ( trifluoroacetyl ) derivative of the corresponding bicyclic urea.