Synthesis and antimicrobial evaluation of some novel bis-α,β-unsaturated ketones, nicotinonitrile, 1,2-dihydropyridine-3-carbonitrile, fused thieno[2,3-b]pyridine and pyrazolo[3,4-b]pyridine derivatives.
The title compounds were prepared by reaction of 1,1'-(5-methyl-1-phenyl-1H-pyrazole-3,4-diyl)diethanone (1) with different aromatic aldehydes 2a-c, namely  Furfural (2a), 4-chlorobenzaldehyde (2b) and 4-methoxybenzaldhyde (2c) to yield  the corresponding α,β-unsaturated ketones 3a-c. Compound 3 was reacted with  malononitrile, 2-cyanoacetamide or 2-cyanothioacetamide yielded the corresponding  bis[2-amino-6-(aryl)nicotinonitrile] 4a-c, bis[6-(2-aryl)-2-oxo-1,2-dihydropyridine-3-carbonitrile] 5a-c or bis[6-(2-aryl)-2-thioxo-1,2-dihydropyridine-3-carbonitrile] 6a,b, respectively. The reaction of compound 6a with each of 2-chloro-N-(4-bromophenyl) acetamide (7a), chloroacetamide (7b) in ethanolic sodium ethoxide solution at room temperature to give the corresponding 4,4'-(5-methyl-1-phenyl-1H-pyrazole-3,4-diyl)bis-6-(2-furyl)thieno[2,3-b]pyridine-2-carboxamide] derivatives 9a,b. While compound 6a reacted with hydrazine hydrate yielded the 4,4'-(5-methyl-1-phenyl-1H-pyrazole-3,4-diyl)bis[6-(2-furyl)-1H-pyrazolo[3,4-b]pyridin-3-amine] 11. The structures of the products were elucidated based on their spectral properties, elemental analyses and, wherever possible, by alternate synthesis. Antimicrobial evaluation of the products was carried out.
Department of Measurements and Environmental Applications, National Institute of Laser Enhanced Sciences (NILES), Cairo University, Giza 12613, Egypt. F_altalbawy@yahoo.com
Farag M A
FM
Altalbawy