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Reactive dyes for cellulose. An unexpected hydrolysis product of a triazinyl reactive dye with a 3–carboxypyridine (nicotinic acid) leaving group
Author(s) -
Taylor J A,
Renfrew A H M
Publication year - 1990
Publication title -
journal of the society of dyers and colourists
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.297
H-Index - 49
eISSN - 1478-4408
pISSN - 0037-9859
DOI - 10.1111/j.1478-4408.1990.tb01259.x
Subject(s) - chemistry , pyridinium , hydrolysis , derivative (finance) , dyeing , nicotinic agonist , salt (chemistry) , aqueous solution , reactive dye , reaction rate constant , medicinal chemistry , organic chemistry , polymer chemistry , kinetics , biochemistry , physics , receptor , quantum mechanics , financial economics , economics
During a recent investigation into the relative rates of hydrolysis of a series of triazinyl reactive dyes bearing various leaving groups, an unexpected reaction was observed in the case of a nicotinic acid derivative. In model studies in dilute aqueous sodium carbonate solution none of the expected hydroxytriazine was detected; instead the aminotriazine was formed cleanly and rapidly (pseudo–first–order rate constant k = 1. 60 times 10 ‐1 min ‐1 ). The nicotinamide derivative behaved similarly. Other pyridinium derivatives examined all behaved as expected, yielding the hydroxytriazine, but at much slower rates (e. g. k = 1. 28 times 10– 3 min ‐1 for the unsubstituted pyridinium salt). A possible mechanism to account for the rapid generation of aminotriazine is proposed and the significance of this observation to the dyeing of cotton with quaternised nicotinic acid dyes under basic and neutral conditions is discussed.