Abstract
1-alkyl aryl-5-amino-4-(cyanoformimidoyl)imidazoles
were reacted with malononitrile and 2-amino-1,1,3-propenetricarbonitrile under mild experimental conditions, which led to 5-amino-3-(substituted benzyl)-6,7-dicyano-3
-imidazo[4,5-
]pyridines
and 6,8-diamino-3-(4-substituted benzyl)-3
-imidazo[4,5-
]-1,8-naphthyridine-7,9-dicarbonitrile
, respectively, when the reaction was carried out in the absence of a base, or to 5,7-diamino-3-(4-alkyl aryl)-3
-imidazo[4,5-
]pyridine-6-carbonitrile
, and 6,8,9-triamino-3-(4-substitutedbenzyl)-3
-imidazo[4,5-
]-1,8-naphthyridine-7-carbonitrile
in the presence of 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU). Both reactions evolved from an adduct formed by nucleophilic attack of the malononitrile anion or 2-amino-1,1,3-propenetricarbonitrile anion to the carbon of the cyanoformimidoyl substituent. In the case of the malononitrile anion, a 5-amino-1-alkyl aryl-4-(1-amino-2,2-dicyanovinyl)imidazole
was isolated when this reaction was carried out in the presence of DBU. The structure of compound
was confirmed by spectroscopic methods, and cyclized intramolecularly to
by heating in ethanol/triethyl amine.