Ring-Chain Tautomerism of the Condensation Products of 2-Mercaptobenzohydrazide with Aliphatic and Aromatic Aldehydes: Influence of Electronic and Steric Factors - Open Access Library Journal

OALibJ > Vol.4 No.5, May 2017

Volume 4, Issue 5 (May 2017)

ISSN Print: 2333-9705 ISSN Online: 2333-9721

Google-based Impact Factor: 1.18 Citations

Ring-Chain Tautomerism of the Condensation Products of 2-Mercaptobenzohydrazide with Aliphatic and Aromatic Aldehydes: Influence of Electronic and Steric Factors ()

HTML XML

Download as PDF (Size: 455KB) PP. 1-10

DOI: 10.4236/oalib.1103584 720 Downloads 1,484 Views Citations

Author(s)

Andrei Yu Ershov^1*, Igor V. Lagoda², Marina Yu Vasileva¹, Stanislav I. Yakimovich³, Boris V. Chernitsa¹, Lyudmila Yu Kuleshova⁴, Lyudmila V. Pavlova², Aleksandr V. Yakimansky¹

Affiliation(s)

¹Institute of Macromolecular Compounds, Russian Academy of Sciences, Saint Petersburg, Russia.
²Scientific Research Test Center, Institute of Military Medicine, Saint Petersburg, Russia.
³Saint Petersburg State University, Saint Petersburg, Russia.
⁴I. P. Pavlov Ryazan State Medical University, Ryazan, Russia.

ABSTRACT

It has been shown by ¹H and ¹³C NMR spectroscopy that 2-mercaptobenzoyl-hydrazones of aliphatic and aromatic aldehydes exist in solution as tautomeric mixtures of linear and cyclic benzo-1,3,4-thiadiazepine forms. The linear hydrazone form is represented by (E,E')-and (E,Z')-conformational isomers, differing in the disposition relative to the amide C–N bond. Growing bulk of the alkyl substituent at the C=N bond of the aliphatic aldehydes derivatives decreases the fraction of the cyclic tautomer; therewith the logarithms of the constants of the chain-ring tautomeric equilibrium correlate with the E_S steric constants of the alkyl substituents. In the series of the aromatic aldehydes 2-mercaptobenzoylhydrazones the linear tautomer prevails, and the logarithms of the tautomeric equilibrium constants K_T correlate with the σ-constants of the substituents in the aromatic nucleus.

KEYWORDS

Hammett and Taft Equations, Ring-Chain Tautomerism 2-Mercaptobenzoylhydrazones, Benzo-1, 3, 4-Thiadiazepines

Share and Cite:

Ershov, A. , Lagoda, I. , Vasileva, M. , Yakimovich, S. , Chernitsa, B. , Kuleshova, L. , Pavlova, L. and Yakimansky, A. (2017) Ring-Chain Tautomerism of the Condensation Products of 2-Mercaptobenzohydrazide with Aliphatic and Aromatic Aldehydes: Influence of Electronic and Steric Factors. Open Access Library Journal, 4, 1-10. doi: 10.4236/oalib.1103584.

Cited by