Antimicrobial Evaluation of New Quinoxaline Derivatives Synthesized by Selective Coupling with Alkyl Halides and Amino Acids Esters

作者:Boraei Ahmed T A*; El Tamany El Sayed H; Ali Ibrahim A I; Gebriel Sara M
来源:Journal of Heterocyclic Chemistry, 2017, 54(5): 2881-2888.
DOI:10.1002/jhet.2896

摘要

Alkylation of quinoxaline scaffold 1 in the presence of K2CO3 preferred N-alkylation than O-alkylation. Quinoxaline hydrazide 6 was successfully coupled with various amino acids, esters, and amines via azide-coupling method. New heterocyclic compounds containing quinoxaline linked to 1,3,4-oxadiazolethione or pyrazole were obtained from cyclization of 6 with CS2 and acetylacetone, respectively. A series of hydrazide Schiff's bases were formed from hydrazide 6 by condensation with a set of aldehydes and ketones. NMR spectroscopy and mass spectrometry were used for structure elucidation of new compounds. The antimicrobial activity of the synthesized compounds was investigated toward two wild-type bacterial strains (Staphylococcus aureus and Escherichia coli) and two fungal species (Alternaria brassicicola and Fusarium oxysporum). Four compounds displayed a significant activity toward S.aureus. The ester 4 showed higher activity than the standard drugs, which make it a promising lead compound.

  • 出版日期2017-9