SYNTHESIS OF 4-SUBSTITUTED 8-AMINO-4,5-DIHYDRO-3H-PYRROLO[3,4-F]-1,3,5-TRIAZEPIN-6-ONES AND 5-AMINO-2-ARYL-4-(1-ARYL-5-ALKYLIDENEAMINOIMIDAZOL-4-YL)1,3-OXAZOLES

The title compounds have been prepared from (Z)-N-2-(2-amino-1,2-dicyanovinyl)formimidamide by reaction of an excess of an aldehyde or ketone in the presence of a base. The triazepine le can also be obtained by the reaction of ethyl (Z) -N-(2-carbamoyl-1-cyano-2-isopropylideneaminovinyl)-formimidate 7a with ammonia and a catalytic amount of anilinium hydrochloride. Under similar conditions the 2-benzylideneamino derivative 7b affords the corresponding amidine 6, and only a low yield of the triazepine. In this last reaction aminolysis of the alkylideneamino bond competes with amidine formation to give compound 8, and reaction between the formimidate 7c and p-anisidine resulted only in the formation of ethyl (Z)-N-(2-amino-2-carbamoyl-1-cyanovinyl)-formimidate 8. Reactions between N-2-aryl-(Z)-N-1-(2-amino-1,2-dicyanovinyl)formimidamides and aldehydes in the presence of a base do not give 1,3,5-triazepines, but instead afford novel 5-amino-2-aryl-4-(1 -aryl-5-alkylideneaminoimidazol-4-yl)-1,3-oxazoles 11 together with the known 9-aryl-6-carbamoyl-1,2-dihydropurines, the corresponding purines and other products.