Synthesis of 4-amino-1H-benzo[4,5]imidazo[1,2-a]pyrimidin-2-one and its disperse azo dyes. Part 1: Phenylazo derivatives

Karci F., Demircali A., Sener I., Tilki T.

DYES AND PIGMENTS, vol.71, no.2, pp.90-96, 2006 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 71 Issue: 2
  • Publication Date: 2006
  • Doi Number: 10.1016/j.dyepig.2005.06.006
  • Title of Journal : DYES AND PIGMENTS
  • Page Numbers: pp.90-96

Abstract

The reaction of 2-aminobenzimidazole with ethyl cyanoacetate gave access to an efficient synthesis of 4-amino-1H-benzo[4,5]imidazo[1,2-a]pyrimidin-2-one (1) in excellent yield. A series of novel phenylazopyrimidone dyes were prepared by linking o-, m-, p-nitroaniline, o-, m-, p-chloroaniline, o-, m-, p-anisidine, o-, m-, p-toluidine and aniline to 4-amino-1H-benzo[4,5]imidazo[1,2-a]pyrimidin-2-one (1). The prepared compounds were characterized by UV-vis, FT-IR and H-1 NMR spectroscopic techniques and elemental analysis. The effect of varying pH and solvent upon the absorption ability of phenylazopyrimidones substituted with electron-withdrawing and electron-donating groups at their o-, m-, p-position was examined. (c) 2005 Elsevier Ltd. All rights reserved.