SYNTHESIS AND CHARACTERIZATION OF CARBAZOLE-BASED AZO ACYLHYDRAZONE SCHIFF BASES

Abstract

Two series of novel azo Schiff bases were synthesized from the condensation reaction of 5-(4-X-phenyl)-azo-salicylaldehyde (X˭H, Cl, NO₂, CH₃) with 4-(N-carbazole methyl) benzhydrazide and N-carbazole acethydrazide, respectively. The 5-(4-X-phenyl)-azo-salicylaldehyde was prepared by diazotization reaction of the corresponding aniline derivatives and then the coupling reaction with salicylaldehyde. The Schiff bases as well as their intermediates were characterized by IR, MS, ¹H NMR, and elemental analysis. The synthesis conditions of azo Schiff bases are discussed in detail. The results indicate that temperature and acidity have a great effect on the above two-step reaction and the aniline derivatives containing electron-withdrawing groups are more difficult to be coupled than those containing electron-donating groups.

Keywords:

• Acylhydrazone
• Carbazole
• Diazotization
• Schiff base
• Synthesis

Acknowledgment

The authors are grateful for the financial support of the National Natural Science Foundation of China (No. J0830415), and the Natural Science Foundation of Hunan Province (No. 11JJ5005). We thank Dr. William Hickey for English editing on this article.