Etherspaltung an Pyridinen mit ungewöhnlichem Halogenierungsverlauf zu isomeren Diamino-pyridon-carbonitrilen und ihre Verwendung als Kupplungskomponenten

Ether cleavage of the two isomeric diamino-methoxy-pyridine-carbonitriles1 and2 leads to the isomeric 4,6-diamino-2(1H)-pyridone-3-carbonitrile (3 a) and 2,4-diamino-6(1H)-pyridone-3-carbonitrile (4 a), resp. Dependent on the reaction conditions in glacial acetic acid containing hydrogen bromide or potassium iodide the halogenated pyridones (3 b, 4 b–c) can be obtained.pK _s -values and UV-spectra of the pyridones are discussed.3 a and4 a can be used as azo-coupling components, yielding the azo-dyes5 and6. Similarly 4-amino-6-hydroxy-2(1H)-pyridones (7 a–b) are coupled with several aryl- and heteroaryl-diazoniumsalts to form the azo-dyes8 a–g.

Herrn emer. o. Univ.-Prof. Dr.Otto Hromatka zum 80. Geburtstag gewidemet.