- Syntheses with Nitriles, LXIX. Isomeric Diamino Alkoxy Pyridine Carbonitriles-Separation and Application as Coupling Components
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The isomeric 4,6-diamino-2-alkoxy- (3), and 2,4-diamino-6-alkoxy-3-pyridine-carbonitriles (4) are obtained by treatment of 2-amino-1,1,3-tricyanopropene (1) with sodium alkoxides.Separation is based on their different pKα-values (3a = 2.01, 4a = 4.17).Coupling reaction of 3a-c with benzenediazonium chloride in strong acidic medium leads to the yellow azo dyes 5a-c, whereas coupling of 4a requires a buffered solution (pH 4-6) to yield 6.The UV-VIS spectra of the isomer pyridines and the azo dyes are discussed. - keywords: Azo Dyes; Diamino-alkoxy-pyridine-carbonitriles; UV-VIS spectra
- Junek, Hans,Uray, Georg,Kotzent, Anna
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- Basic diaminopyridine-(3)-azo dyestuffs
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A basic azo dyestuff, which is free form acid groups conferring solubility in water, of the formula STR1 wherein two radicals Z represent groups of the formula --NR'R" and one radical Z represents a group of the formula --NR'R", --OR'" or --SR'", wherein R', R", and R'" each represents hydrogen, aryl, cycloalkyl or an aliphatic radical and R' and R" are able to form a ring containing the amino nitrogen and the radicals --NR'R" may be the same or different, R is alkyl, substituted alkyl or cycloalkyl, n is 1 or 2, Y represents a radical of the formula --CN or --CONH2, and D represents the radical of an aromatic or heterocyclic diazo component, and wherein at least one radical Z and/or D contains a basic, optionally cationic group. These dyestuffs are useful for dyeing and printing synthetic fibers to produce intensive and level dyeings with good fastness to light and general fastness properties.
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