title: A Simple Precursor for Highly Functionalized Fused Imidazo[4,5-b]pyridines and Imidazo[4,5-b]-1,8-naphthyridine.
abstract: 1-alkyl aryl-5-amino-4-(cyanoformimidoyl)imidazoles4were 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-3H-imidazo[4,5-b]pyridines5and 6,8-diamino-3-(4-substituted benzyl)-3H-imidazo[4,5-b]-1,8-naphthyridine-7,9-dicarbonitrile6, respectively, when the reaction was carried out in the absence of a base, or to 5,7-diamino-3-(4-alkyl aryl)-3H-imidazo[4,5-b]pyridine-6-carbonitrile8, and 6,8,9-triamino-3-(4-substitutedbenzyl)-3H-imidazo[4,5-b]-1,8-naphthyridine-7-carbonitrile10in 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)imidazole7was isolated when this reaction was carried out in the presence of DBU. The structure of compound7was confirmed by spectroscopic methods, and cyclized intramolecularly to8by heating in ethanol/triethyl amine.
authors.affiliation: Chemistry Department, College of Science, IMSIU (Al-Imam Mohammad Ibn Saud Islamic University), Riyadh 11623, Saudi Arabia. okduaij@imamu.edu.sa.
authors.forename: Omar K
authors.initials: OK
authors.lastname: Al-Duaij
authors.affiliation: Chemistry Department, College of Science, IMSIU (Al-Imam Mohammad Ibn Saud Islamic University), Riyadh 11623, Saudi Arabia. mezaki@imamu.edu.sa.|Photochemistry Department, National Research Centre, Cairo 12622, Egypt. mezaki@imamu.edu.sa.
authors.forename: Magdi E A
authors.initials: ME
authors.lastname: Zaki
authors.affiliation: Chemistry Department, College of Science, IMSIU (Al-Imam Mohammad Ibn Saud Islamic University), Riyadh 11623, Saudi Arabia. abagazzar@imamu.edu.sa.|Photochemistry Department, National Research Centre, Cairo 12622, Egypt. abagazzar@imamu.edu.sa.
authors.forename: Abdel-Rhman B A
authors.initials: AB
authors.lastname: El Gazzar
mesh_terms: D009287:Naphthyridines / Q000138:chemical synthesis* / Q000737:chemistry*; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D009287:Naphthyridines; D011725:Pyridines
keywords: 2-amino-1,1,3-propenetricarbonitrile; carbon acid; diaminomaleonitrile; imidazo[4,5-b]-1,8-naphthyridine; imidazo[4,5-b]pyridine; malomonitrile