Synthesis and spectral properties of symmetrical and asymmetrical 3-cyano-1,5-diarylformazan dyestuffs for dyeing polyester fabrics
作者:Tawfik Khattab、Karima M. Haggag
DOI:10.21608/ejchem.2017.1479.1103
日期:2017.12.1
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.
在本研究中,我们报告了一种合成对称和非对称3-氰基-1,5-二芳基福尔马赞染料的普遍合成方法。酰胺氰与芳香族重氮盐在稍微酸性的介质中反应,生成作为稳定中间体的芳基肼醛,这些中间体可以通过在弱碱介质中进行二次偶氮偶联反应,转化为非对称福尔马赞。对称福尔马赞染料则通过将关键中间体3-哌啶基丙烯腈与相应的重氮盐在弱碱性介质中进行双偶氮偶联反应直接合成,采用醋酸钠作为弱碱。通过元素分析(C、H、N)、1H和13C NMR、FTIR和GC-MS光谱技术证明所制备染料和中间体的结构。所制备的福尔马赞分散色料应用于聚酯面料的染色,获得良好的洗涤、汗液、摩擦和光照的牢度性能。