1070-4272/05/7801-0120C2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 1, 2005, pp. 120!124. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 1,
2005, pp. 122!126.
Original Russian Text Copyright + 2005 by Dikusar, Vyglazov, Moiseichuk, Zhukovskaya, Kozlov.
AND INDUSTRIAL ORGANIC CHEMISTRY
Preparative Synthesis of Vanillin and Vanillal Alkanoates
E. A. Dikusar, O. G. Vyglazov, K. L. Moiseichuk, N. A. Zhukovskaya, and N. G. Kozlov
Institute of Physical Organic Chemistry, Belarussian National Academy of Sciences, Minsk, Belarus
Tereza Inter Limited Liability Company, Moscow, Russia
Received June 16, 2004
Abstract-Procedures for preparing vanillin and vanillal alkanoates were developed.
Vanillin (4-hydroxy-3-methoxybenzaldehyde, Ia)
and its homolog, vanillal (4-hydroxy-3-ethoxybenzal-
dehyde, Ib) are widely used in food and perfume
industries . Vanillin can also be used as a syn-
thetic precursor of biologically active substances
[4, 5]. However, new processes in food industry de-
mand new aroma chemicals that would have vanilla
smell but be more heat-resistant than vanillin and
stable in a wide range of pH in the presence of en-
zymes. These requirements stimulate chemists to
prepare new vanillin and vanillal derivatives; many of
them appeared to exhibit stronger vanilla smell, com-
pared to the initial compounds, with diverse tints.
Here we report convenient synthetic routes to
vanillin (IIa!IIm) and vanillal (IIIa!IIIg) esters.
II a3m, III a3g
II a3m, III a3g
II, R = Me, R` =H(a), Me (b), Et (c), Pr (d), Me
(e), Bu (f), Me
Cl (l), 4-MeC
(m); III, R = Et, R` =H(a), Me (b), Et (c), Pr (d),
CH (e), Bu (f), Me
Some of them were characterized , but the
lack of some esters in the homologous series of the
vanillin and vanillal derivatives and incompleteness
of the available physicochemical data for the previ-
ously described compounds stimulated us to make this
study, aimed to develop new flavor additives derived
from vanillin and vanillal.
The formates were prepared by the reactions of
vanillin Ia and vanillal Ib with formic acid in the
presence of dicyclohexylcarbodiimide , which is
a simpler procedure compared to the known routes
. The other esters IIb!IIm and IIIb!IIIg were
prepared by reactions of Ia and Ib with alkanecarbox-
ylic acid chlorides in the presence of pyridine [15,
16]. To simplify the production process and improve
the purity of the target products for their use in formu-
lations for perfume and food industry, the esters were
also prepared by the Schotten3Baumann reaction [9,
17]. The resulting esters IIb!IIe and IIIb!IIIe
(Tables 1, 2) do not require additional purification.
They are free of benzene and pyridine impurities and
can be directly used in the perfume industry.
The organoleptic assessment of the scents of IIa!
IIg and IIIa!IIIg was made by the Tasting Council
at the Accredited Checkout and Analytical Laboratory
of the Tereza Inter Limited Liability Company (Mos-
cow, Russia). Esters IIa!IIg and IIIa!IIIg have
pronounced vanilla smell with various intense tints
(Table 3). Esters IIh!IIm have no odor.
The IR spectra of the compounds were recorded on
a Protege-460 IR Fourier spectrometer (Nicolet) from
the samples prepared as thin films or KBr pellets; the
UV spectra, on a Specord UV-Vis spectrophotometer
from 1 0 10
M solutions in 1-butanol; the
spectra, on a BS-587A spectrometer (100 MHz, Tesla)
from 5% solutions in CDCl
, with octamethyltetracyc-
losiloxane as internal reference; and the mass spectra,
on a Chrommas GC/MS Hewlett3Packard 5890/5972
gas chromatograph3mass spectrometer equipped with
an HP-5MS column, at an ionizing electron energy
of 70 eV.
Alkanecarboxylic acid chlorides were prepared by
refluxing the corresponding carboxylic acids with a
1.5-fold excess of SOCl