1028
ZHURAVLEV et al.
Table 2. Characteristics of the vibration spectra of the
synthesized compounds
cease of CO2 release. Insoluble salt NaCl was filtered
off, and the mother liquor was evaporated to dryness in
a vacuum. Crystalline pyridoxine was immediately
used in the synthesis. Pyridoxine, a representative of
vitamins of B6 group, is a component of enzymes
involved in protein metabolism.
Run
Characteristic absorption bands, cm–1
no.
2
δC–H (mono) 710–670
3
νC=O (amide I) 1700, 1650; νN–H 3450–3400; δN–H 1610,
General procedure for preparation of quaternary
salts. 0.05 mol of amine and 0.075 mol of the
quaternizing agent were dissolved separately in a
double volume of anhydrous alcohol. The solutions
were combined and left for 30 minutes, and then
heated for 0.5–1 h in a water bath. The solvent was
evaporated in a vacuum, the residue was treated twice
with small portions of dry cold ether to remove un-
reacted substances and then the salt was recrystallized
from a mixture of dry ethyl acetate and ethyl alcohol
(1:1). For all the synthesized salts a general test for
halogen was carried out (test with AgNO3) which was
positive. The quaternary salts are soluble in water,
alcohol, acetone, insoluble in ether. Yields and
constants are listed in Table 1.
1580
4
5
νO–H 3560–3300
νC–O–C 1275–1250, νC=O 1710, 1680
6
νC–Car 1620, 1500, 1400, νC–Har 3080, νC–H 2980
7
8
νC=O (amide I) 1710, 1690; νN–H 3400, 3350
–
9
10
11
νC–Car 1610, 1450; νC–Har 3095, 3020; δC–Har 720, 696
νC–Car 1610, 1580, νC–Har 3085, νC–H 2980
–
of the phenyl group (–I-effect) is much weaker and C–
Br bond is stronger, and that defines the lower
reactivity of the latter compound. It is possible that the
reaction is complicated also by the elimination of HBr
and the formation of an olefin.
The synthesis conditions were slightly changed in
the case of difficultly forming salts at the quaterniza-
tion of amines with β-phenylethyl bromide. In this case
more polar solvent nitromethane was used and the
reaction time was increased to 15–20 h. At the
quaternization of pyridoxine with β-phenylethyl
bromide only trace amounts of product were obtained,
which were not analyzed.
EXPERIMENTAL
Precursors. Substrates: phenacyl bromide (mp 51–
52°C) and p-metoxyphenacyl bromide (mp 69–70°C)
were prepared by bromination of respective ketones,
acetophenone and p-methoxyacetophenone, using the
general procedure [4]. β-Phenylethyl bromide (1-
phenyl-2-bromoethane), bp 98°C (14 mm Hg) was
obtained by reaction of phenethyl alcohol with 48%
hydrobromic acid according to the general procedure
[5].
In the spectra of all investigated compounds there
were absorption bands of aromatic rings (νCCar 1650,
1580, 1400; νCHar 3030, 3010 cm–1). In the spectra of
the derivatives there were extra absorption bands of
functional groups (Table 2).
REFERENCES
1. Hartwell, J.L. and Kornberg, S.L., J. Am. Chem. Soc.,
Nucleophiles: Pyridine (bp 115°C), β-picoline (3-
methylpyridine, bp 144°C), nicotinamide (mp 129–
131°C, vitamin B3, the antipellargic vitamin that
belongs to the enzyme systems involved in the
processes of cellular respiration) were commercial
products, purified by distillation or recrystallization.
Pyridoxine [adermin, 2-methyl-3-hydroxy-4,5-di-(hyd-
roxymethyl)pyridine] was obtained from the respective
hydrochloride (drug) by heating its suspension in
anhydrous alcohol with an excess of NaHCO3 until the
1945, vol. 67, p. 1606.
2. Zhdanov, Yu.A. and Minkin, V.I., Korrelyatsionnyi
analiz v organicheskoi khimii (Correlation Analysis in
Organic Chemistry), Rostov: Rostov. Gos. Univ., 1966,
p. 86.
3. Joule, J.A. and Smith, G.F., Geterotsiklicheskaya khi-
miya (Heterocyclic Chemistry), Moscow: Mir, 1975,
p. 75.
4. Organikum, Moscow: Mir, 1979, vol. 2, p. 173.
5. Organikum, Moscow: Mir, 1979, vol. 2, p. 255.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 80 No. 5 2010