Abstract
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.
Highlights
The synthesis of a wide variety of bis heterocyclic compounds of different ring sizes with one or several heteroatoms has received a great deal of attention, as model compounds for main chain polymers and because many biologically active natural and synthetic products have molecular symmetry [1,2,3,4,5,6,7,8]
3-Cyano-2(1H)-pyridinethiones [36,37] and their related compounds were found to be very reactive substances for the synthesis of many different heterocyclic systems which exhibited biological activities such as antibacterial and antifungal [38]. In light of these findings, we report here the synthesis of some novel bis-heterocycles containing N-phenylpyrazole as a base unit
Condensation of compounds 3a–c with malononitrile in the presence of ammonium acetate in n-butanol afforded the corresponding 4,4'-(5-methyl-1-phenyl-1H-pyrazole-3,4-diyl) bis[2-amino-6(aryl)nicotinonitrile] 4a–c were prepared in fair yields by applying the aforementioned one pot reaction of the compound 1, the corresponding aldehyde and malononitrile in the presence of ammonium acetate (Scheme 2)
Summary
The synthesis of a wide variety of bis heterocyclic compounds of different ring sizes with one or several heteroatoms has received a great deal of attention, as model compounds for main chain polymers and because many biologically active natural and synthetic products have molecular symmetry [1,2,3,4,5,6,7,8]. Α,β-unsaturated ketones (Chalcones) derivatives have a variety of pharmacological activities such as antimalarial [9], anticancer [10,11,12,13], anti-inflammatory [14], antibacterial [15], antifungal agents [16]. 3-Cyano-2(1H)-pyridinethiones [36,37] and their related compounds were found to be very reactive substances for the synthesis of many different heterocyclic systems which exhibited biological activities such as antibacterial and antifungal [38]. In light of these findings, we report here the synthesis of some novel bis-heterocycles containing N-phenylpyrazole as a base unit. Synthesis of bis[2-amino-6-(aryl)nicotinonitrile] 4a–c, bis[6-(2-aryl)-2-oxo-1,2dihydropyridine-3-carbonitrile] 5a–c and bis[6-(2-aryl)-2-thioxo-1,2-dihydropyridine-3carbonitrile] 6a,b
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
