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Synthesis of 2‐azo‐3‐cyano‐5‐carbethoxy thiophene derivatives and their application on polyester fibres
Author(s) -
Sabnis Ram W.,
Rangnekar Dinesh W.
Publication year - 1990
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.280470106
Subject(s) - thiophene , malononitrile , diethylamine , polyester , chemistry , aryl , acetic acid , organic chemistry , yield (engineering) , acetone , polymer chemistry , catalysis , materials science , metallurgy , alkyl
Synthesis of 2‐(hetaryl or aryl)‐azo thiophene derivatives ( IVa–IVg ) was achieved by diazotisation of ethyl 2‐amino‐3‐cyano‐5‐carbethoxy thiophene‐4‐acetic acid ester ( I ) using nitrosyl sulphuric acid, coupling with suitable heterocyclic hydroxy and N, N‐dialkyl‐substituted aryl amines, which resulted in thiophene azo dyes. The key intermediate ( I ), used as the diazonium component was synthesised in one pot and in excellent yield from diethyl acetone dicarboxylate, sulphur and malononitrile, using diethylamine as a catalyst, following the Gewald Synthesis. The spectral properties of these dyes were studied. The dyes when applied as disperse dyes on polyester fibres gave excellent results.