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Synthesis, 1 H, 13 C and 15 N NMR Study of Azo Coupling Products from Enaminones
Author(s) -
Šimůnek Petr,
Lyčka Antonín,
Macháček Vladimír
Publication year - 2002
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/1099-0690(200208)2002:16<2764::aid-ejoc2764>3.0.co;2-b
Subject(s) - chemistry , azo coupling , tautomer , carbon 13 nmr , tetrafluoroborate , nuclear magnetic resonance spectroscopy , derivative (finance) , molar ratio , proton nmr , nmr spectra database , medicinal chemistry , computational chemistry , stereochemistry , spectral line , polymer chemistry , organic chemistry , catalysis , ionic liquid , physics , astronomy , financial economics , economics
Compounds 2 were prepared by the reaction of 3‐amino‐5,5‐dimethylcyclohex‐2‐en‐1‐one and its N ‐phenyl derivative with substituted benzenediazonium tetrafluoroborates, and their 1 H, 13 C and 15 N NMR spectra were measured and analysed. The active components react with enaminones in molar ratios of 2:1. Only in the case of 4‐methoxybenzenediazonium tetrafluoroborate and 3‐amino‐5,5‐dimethylcyclohex‐2‐en‐1‐one were traces of the product of the 1:1 reaction observed. The attack by the diazonium component occurs at carbon atoms C‐2 and C‐4, and the hydrazo form is always formed at the 2‐position. 15 N NMR spectroscopy was adopted to study the position of the tautomeric equilibrium (arylazo − arylhydrazono) at the 4‐position: this equilibrium depends predominantly on the substituents of the amino group and, to a lesser extent, on the substituents of the diazonium component. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)