SYNTHESIS OF WATER-SOLUBLE AZOMETHINES
2657
absorption and the propensity to tarring in contact with
atmospheric oxygen we were not able to obtain these
compounds in a pure form).
relative to the internal reference TMS. Elemental
analysis was made on the a Vario EL-III Elementar
C,H,N,O,S-analyzer, error of determination was 0.1%.
In the IR spectra of azomethines IIIa–IIIx, IVa–
IVn the following characteristic absorption bands were
observed (ν, cm–1): OH 3550–3050; CHarom 3080–
3005, 870–620; CHaliph 2990 – 2830; C=O ester 1770–
1740 (IIIe–IIIx, IVc–IVn, VIa, VIb); C=N 1640–
1637; C=Carom 1607–1420; CO 1270–1030. The
presence of the NO2 group in compound IIIs was
confirmed by the characteristic absorption bands at
1531 and 1348 cm–1. In the IR spectra of the carbo-
rane-containing azomethines IIIw, IIIx, IVm, and IVn
there are absorption bands CHcarbor 3070 (IIIw, IVo)
and 3033 (IIIx, IVn) and BH 2680–2655 cm–1.
Esters of vanillin and vanillal (I) were obtained
along the methods [4–9].
The initial D-(+)-glucosamine hydrochloride (II)
was of “chemically pure” grade, purity 99%, mp 190°C
(decomp.), [α]D20 = +72°.
Water-soluble azomethines (IIIa–IIIx, IVa–IVn).
A mixture of 5 mmol of a benzaldehyde derivative of
vanillin series I, D-(+)-glucosamine hydrochloride II,
and 5 mmol of potassium hydrogen carbonate in 40 ml
of anhydrous methanol was refluxed for 3–4 h under
an argon atmosphere. A hot solution was filtered through
a plaited paper filter to remove KCl, the solvent was then
removed in a vacuum. Azomethines IIIa–IIIx, IVa–
IVn were purified by dissolving in 10 ml of anhydrous
methanol and precipitating by adding 20 ml of ether,
the precipitated azomethine was rapidly filtered
through a porous glass filter and dried in a vacuum.
In the UV spectra of compounds IIIe–IIIx, IVc–
IVn there are the characteristic absorption maxima,
λ
max, nm (ε): 208 (14000), 220 (13000), 255 (10000),
300 (400), due to the presence in the molecules of 4-
acyloxy-3-alkoxybenzylidenamine fragments.
1
In the H NMR spectra of azomethines IIIa–IIIx,
REFERENCES
IVa–IVn the signals of the protons of glucosamine
fragment are multiplets at 3.10–3.80 ppm. In the H
1
1. Sharnina, F.F., Ivashina, T.N., and Ivashin, V.P.,
Struktura i dinamika molekulyarnykh sistem (Structure
and Dynamics of Molecular Systems), Ioshkar-Ola, Ufa,
Kazan, Moscow, 2003, no. 10, part 2, p. 274.
2. Daier, D.R., Prilozheniya absorbtsionnoi spektroskopii
organicheskikh soedinenii (Applications of Absorption
Spectroscopy of Organic Compounds), Moscow:
Khimiya, 1970, p. 92.
3. Dikusar, E.A., Kozlov, N.G., Tlegenov, R.T., and
Uteniyazov, K.U., Azometiny na osnove vanilina i vani-
lalya (Azomethines Based on Vanillin and Vanillal),
Nukus: Karakalpakstan, 2007.
NMR spectra of azomethines IIIb–IIIx, IVb, VIa the
signals of MeO group protons appear as singlets in the
region of 3.75–3.85 ppm. In the spectra of compound
IVa–IVn, VIb the signals of EtO group protons appear
in the form of a triplet at 0.90–1.30 ppm (Me) and a
quartet at 3.80–4.20 ppm (CH2). The signals of
aromatic protons in compounds IIIa–IIIx, IVa–IVn,
V, VIa, VIb are in the range of 6.80–8.00 ppm, the
signals of the protons of azomethine group (HC=N)
appear as a singlet at 8.10–8.20 ppm, which is typical
for azomethines of (E)-configuration [2].
In the IR, UV and 1H NMR spectra of azomethines
IIIa–IIIx, IVa–IVn there are the absorption bands and
signals of protons confirming existence of the
structural fragments of ester groups [3].
4. Dikusar, E.A., Vyglazov, O.G., Moiseichuk, K.L.,
Zhukovskaya, N.A., and Kozlov, N.G., Zh. Prikl. Khim.,
2005, vol. 78, no. 1, p. 122.
5. Dikusar, E.A. and Kozlov, N.G., Khim. Prirod. Soedin.,
2005, no. 1, p. 74.
6. Dikusar, E.A. and Kozlov, N.G., Zh. Org. Khim., 2005,
EXPERIMENTAL
vol. 41, no. 7, p. 1015.
The IR spectra of compounds were recorded on a
Fourier-transform IR spectrophotometer Protege-460
of Nicolet from thin layers or KBr pellets, UV spectra
were taken on a Specord UV Vis instrument from
7. Dikusar, E.A., Zh. Prikl. Khim., 2006, vol. 79, no. 6,
p. 1043.
8. Dikusar, E.A., Kozlov, N.G., Potkin, V.I., Zvereva, T.D.,
Yuvchenko, A.P., Bei, M.P., and Kovganko, N.V.,
Khim. Prirod. Soedim., 2006, no. 5, p. 434.
1
1×10–4 M solutions of compounds in methanol, H
NMR spectra were registered on a spectrometer Tesla
BS-587A (100 MHz) from 5% solutions in water-d2 or
dimethylsulfoxide-d6, chemical shifts were determined
9. Dikusar, E.A., Potkin, V.I., Kozlov, N.G., Yuvchenko, A.P.,
Bei, M.P., and Kovganko, N.V., Zh. Org. Khim., 2008,
vol. 44, no. 9, p. 1321.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 79 No. 12 2009
Dikusar
