title: Synthesis of a new class of Pyridazin-3-one and 2-amino-5-arylazopyridine derivatives and their utility in the synthesis of fused azines.
abstract: A general route for the synthesis of a novel class of pyridazin-3-one derivatives 3 by the reaction in acetic anhydride between 3-oxo-2-arylhydrazonopropanals 1 and some active methylene compounds like p-nitrophenylacetic acid and cyanoacetic acid was established. Under these conditions the pyridazin-3-one derivatives 3 were formed as the sole isolable products in excellent yield. The 6-acetyl-3-oxopyridazine derivative 3l was reacted with DMF-DMA to afford the corresponding enaminone derivative 4, which reacts with a variety of aminoazoles to afford the corresponding azolo[1,5-a]pyrimidine derivatives 5-7. Also, in order to explore the viability and generality of a recently uncovered reaction between 3-oxo-2-arylhydrazonopropanals and active methylene compounds, a variety of 2-amino-6-aryl-5-arylazo-3-aroylpyridines 16-19 were prepared by reacting 3-oxo-2-arylhydrazonopropanals with miscellaneous active methylene compounds like 3-oxo-3-phenylpropionitrile, hetaroylacetonitriles and cyanoacetamides. These 2-aminopyridine derivatives undergo smooth reactions with cyanoacetic acid that led to the formation in high yield of a new class of 1,8-naphthyridine derivatives 24. The structures of all new substances prepared in this investigation were determined by the different analytical spectroscopic methods, in addition to the X-ray crystallographic analysis.
authors.affiliation: Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait. hamadaaldeb@yahoo.com.
authors.forename: Hamada Mohamed
authors.initials: HM
authors.lastname: Ibrahim
authors.affiliation: Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait. hidar@bahbahani.com.
authors.forename: Haider
authors.initials: H
authors.lastname: Behbehani
mesh_terms: D000085:Acetates / Q000737:chemistry; D001391:Azo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D011724:Pyridazines / Q000138:chemical synthesis* / Q000737:chemistry; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000085:Acetates; D001391:Azo Compounds; D006571:Heterocyclic Compounds; D011724:Pyridazines; D011725:Pyridines; C062482:pyridazine; C007170:cyanoacetic acid