Synthesis and Spectral Properties of Symmetrical and Asymmetrical 3-Cyano-1,5-diarylformazan Dyestuffs for Dyeing Polyester Fabrics

Document Type : Original Article

Authors

Dyeing, Printing and Auxiliaries Department, Textile Research Division, National Research Centre, Cairo 12622, Egypt

Abstract

In this study, we report on a general synthetic approach to both symmetrical and asymmetrical 3-cyano-1,5-diarylformazan dyes. The reaction of enaminonitrile with aromatic diazonium salts in slightly acidic medium affords arylhydrazonals as stable intermediate that are readily converted into asymmetrical formazans via second azo-coupling in a weak alkaline medium. Symmetrical formazan dyestuffs are synthesized directly via double azo-coupling of the key intermediate 3-piperidinylacrylonitrile with the corresponding diazonium salts in weak alkaline medium using sodium acetate as a weak base. The structures of the prepared dyestuffs and intermediates are demonstrated by elemental analysis (C, H, N), 1H and 13C NMR, FTIR and GC-MS spectroscopic techniques. The prepared formazan disperse colorants are applied to dye polyester fabric to give satisfactory fastness properties to wash, perspiration, rubbing and light.

Keywords

Main Subjects

Files

Cited by

History

  • Receive Date: 13 August 2017
  • Revise Date: 14 September 2017
  • Accept Date: 15 October 2017

Share

How to cite

Statistics