RING-CHAIN TAUTOMERISM OF 2-MERCAPTOBENZOYLHYDRAZONES OF AROMATIC ALDEHYDES

Abstract

It has been shown by ¹H NMR spectroscopy that 2-mercaptobenzoylhydrazones of aromatic aldehydes 2-HSC₆H₄CONHN=CHC₆H₄X (X = 4-NO₂, 3-NO₂, 4-Br, H, 4-Me, 4-MeO, 4-Me₂N) exist in DMSO-d₆ solution as tautomeric mixtures of linear and cyclic benzo-1,3,4-thiadiazepine forms. The linear hydrazone form is represented by (E,Z')-conformational isomers, differing in the disposition relative to the amide C–N bond. It was shown that the logarithm of the tautomeric equilibrium constant K_T correlates with the σ-constants of the substituents in the aromatic nucleus.

How to Cite

Chernitsa, B. V.; Ershov, A. Yu.; Doroshenko, V. A.; Yakimovich, S. I.; Lagoda, I. V.; Zerova, I. V.; Pakal'nis, V. V.; Shamanin, V. V.  Chem. Heterocycl. Compd. 2010, 46, 1133. [Khim. Geterotsikl. Soedin. 2010, 1404.]

For this article in the English edition see DOI 10.1007/s10593-010-0638-3