Synthesis and Spectral Properties of Symmetrical and Asymmetrical 3-Cyano-1,5-diarylformazan Dyestuffs for Dyeing Polyester Fabrics | ||
| Egyptian Journal of Chemistry | ||
| Article 3, Volume 60, Conference Issue (The 8th International Conference of The Textile Research Division (ICTRD 2017), National Research Centre, Cairo 12622, Egypt.), December 2017, Pages 33-40 PDF (637.58 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejchem.2017.1479.1103 | ||
| Authors | ||
| Tawfik Khattab* ; Karima M. Haggag | ||
| 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 | ||
| Cyanoenamine; Hydrazonal; Formazan; Azo-coupling; dyeing; polyester | ||
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