Microwave-Assisted Synthesis of 1,4′-Diazaflavone and N-Alkyl Derivative Pigments with Anti-Microbial Activity

Yayli N. , Uecuencue O. , YAYLI N. , demir E., DEMİRBAĞ Z.

Turkish Journal of Chemistry, vol.32, no.6, pp.785-795, 2008 (Journal Indexed in SCI Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 32 Issue: 6
  • Publication Date: 2008
  • Title of Journal : Turkish Journal of Chemistry
  • Page Numbers: pp.785-795
  • Keywords: 1,4′-diazaflavone, Anti-microbial activity, Aza-chalcone, Microwave-assisted, N-alkyl-1,4′-diazaflavonium bromide, Pigment (3-12)

Abstract

1,4′-Diazaflavone pigment (2) was synthesized by a simple environmentally friendly microwave-assisted one-pot method for the cyclization of 2′-amino (E)-4″-aza-chalcone (1) under solventless conditions using K-10 clay. In addition, 10 new N-alkyl (C5-12,14-15) substituted 1,4′-diazaflavonium bromide pigments (3-12) were prepared from compound 2 or directly from compound 1, with corresponding alkyl halides in acetonitrile under reflux. The anti-microbial activity of compounds 1-12 was tested. The N-alkyl substituted 1,4′-diazaflavonium bromides (3-12) showed good antimicrobial activity against the gram-positive bacteria tested with minimal bactericidal concentration (MBC) values for the reference antibiotic kanamycin. The optimum length of the alkyl chain for better and broader activity was 6-10 carbon atoms in the series of compounds (3-12).