Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 4, pp. 515−519.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © A.V. Pavlov, E.A. Veretennikov, B.M. Laskin, A.G. Egorov, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 4,
AND INDUSTRIAL ORGANIC CHEMISTRY
Correlation between the Rates of Benzylidene Condensation
and Their Dissociation Constants
A. V. Pavlov
, E. A. Veretennikov
, B. M. Laskin
, and A. G. Egorov
Applied Chemistry Russian Research Center, St. Petersburg, Russia
Chemical-Pharmaceutical Technologies, Company Limited, St. Petersburg, Russia
Research Institute of Synthetic Rubber, St. Petersburg, Russia
Received January 28, 2013
Abstract—Benzylidene condensation of R-tetrazol-1-ylphenylamines with 4-ﬂ uorobenzaldehyde was studied.
The correlation between the logarithm of the rate constant of the condensation of 4-ﬂ uorobenzaldehyde with R-
tetrazol-1-ylphenylamines and their рK
+ values was found. The reaction constant ρ in the Hammett equation
It was noted previously  that (4-fluorobenzyl)
(R-tetrazol-1-ylphenyl)amines (1) (R = H) (Scheme 1)
exhibit potential biological activity. It is known that
introduction of substituents with pharmacophore
, Cl) enhances the biological
where R = H, CH
The intermediates for the synthesis of compounds 1,
(4-ﬂ uorobenzylidene)(tetrazol-1-ylphenyl)amines 16–28
(Scheme 2), were prepared by benzylidene condensation
of R-tetrazol-1-ylphenylamines 2–14 with 4-ﬂ uorobenz-
aldehyde 15. Compounds 4, 5, and 14 were prepared and
described previously .
The mechanism of the benzylidene condensation
was studied in sufﬁ cient detail ; as applied to the
compounds under consideration, without introduction of
additional catalysts, it follows Scheme 2.
In this study, continuing our previous work , we
examined the kinetics of the benzylidene condensation
and determined the correlation between the logarithm
of the rate constant of the condensation of R-tetrazol-1-
ylphenylamines 2–14 with 4-ﬂ uorobenzaldehyde 15 and
+ of R-tetrazol-1-ylphenylamines 2–14.
R-Tetrazol-1-ylphenylamines 2–14 with which the
condensation was performed were no less than 99.9 mol %
pure, according to NMR data. 4-Fluorobenzaldehyde
(CAS 459-57-4, Acros Organics) was freshly distilled.
The benzene used for the study was of ultrapure grade.
Н NMR spectra were recorded with a Bruker
WM-400 spectrometer (400 MHz) from solutions in
, the elemental analysis was performed with
a Hewlett–Packard 185B analyzer, and the UV spectro-
photometric analysis was performed with a Shimadzu