Reaction of 1-germatranol hydrate with carboxylic acids

Article abstract of DOI:10.1134/S1070363215120154

Reaction of 1-germatranol hydrate with carboxylic acids RCOOH (R = ClCH₂, PhCH=CH, Ph, 2-FC₆H₄, 3-BrC₆H₄, 3-HOC₆H₄, 3-EtOC₆H₄) in protic (CH₃OH,

Full text of DOI:10.1134/S1070363215120154

ISSN 1070-3632, Russian Journal of General Chemistry, 2015, Vol. 85, No. 12, pp. 2748–2753. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © V.P. Baryshok, N.T.Z. Le, 2015, published in Zhurnal Obshchei Khimii, 2015, Vol. 85, No. 12, pp. 2016–2021.
Reaction of 1-Germatranol Hydrate with Carboxylic Acids
V. P. Baryshoka and N. T. Z. Leb
a Irkutsk National Research Technical University, ul. Lermontova 83, Irkutsk, 664074 Russia
e-mail: baryvik@yandex.ru
b Baria-Vung Tau University, Vung-Tau, Vietnam
Received May 14, 2015
Abstract—Reaction of 1-germatranol hydrate with carboxylic acids RCOOH (R = ClCH2, PhCH=CH, Ph, 2-
FC6H4, 3-BrC6H4, 3-HOC6H4, 3-EtOC6H4) in protic (СН3ОН, iso-С5Н11ОН) and aprotic polar solvent (СН3СN)
is studied. 1-Acyloxygermatranes RC(O)OGe(OCH2CH2)3N are formed in yields from 11 to ~100 % depending
on the nature of the acid, solvent, duration of the process and the method of its completion. The reaction is the
most effective in acetonitrile. Its topochemical completion (heating of the reaction residue in a vacuum)
increases the yield of 1-acyloxygermatranes.
Keywords: hydrate of 1-germatranol, esterification, carboxylic acids, topochemical reaction
DOI: 10.1134/S1070363215120154
Intracomplex tricyclic silicon and germanium
ethers of triethanolamine, silatranes and germatranes,
as a rule, possess similar biological activity [1, 2]. The
adducts of germatranes, including 1-germatranol, with
compounds containing carboxy group and showing
high physiological activity were patented [3–7].
obtained [10]. A series of 1-acyloxygermatranes was
synthesized by the reaction of 1-chlorogermatrane with
potassium salts of carboxylic acids [11]. By successive
reaction of germanium dioxide with triethanolamine
and carboxylic acids in о-xylene and isopentanol we
have recently prepared 1-acyloxygermatranes with the
following substituents in the acyl group RС(О): R =
СН3, 2-MeC6H4CH2OCH2, C6H5, 2-HOC6H4 [12].
The first 1-acyloxygermatrane, 1-acetoxygermatrane
СН3C(O)OGe(OCH2CH2)3N, was prepared in 91%
yield by the reaction of 1-methoxygermatrane with
98% acetic acid and its anhydride in о-dichlorobenzene
at 100°С [8,9]. Later on, from 1-methoxygermatrane
and the corresponding carboxylic acids 1-dichloro-
acetoxy- and 1-diphenylacetoxygermatrane were
In the present work the reaction of 1-germatranol
hydrate N(CH2CH2O)3GeOH·H2O (1) with carboxylic
acids in polar solvents methanol and acetonitrile is
studied in comparison with the reaction in isopentanol
and xylene.
(1)
N(CH2CH2O)3GeOH H2O + RCOOH
N(CH2CH2O)3GeOC(O)R + 2H2O,
2_8
1
R = ClCH2 (2), C6H5CH=CH (3), C6H5 (4), 2-FC6H4 (5), 3-BrC6H4 (6), 3-HOC6H4 (7), 3-C2H5OC6H4 (8).
The yields increased with the duration of the
reaction (Table 1). In the reaction of 1 with cinnamic
acid, apart from product 3, 1-isoamyloxygermatrane 9
is formed; its content in the reaction mixture slightly
increases (from 5.1 to 5.5%) on growth the time of
heating in isoamyl alcohol from 6 to 15 h.
Since the reaction of 1-germatranol with carboxylic
acids is reversible, azeotropic distillation of water
presumably would give better results as compared to
the process without removal of water. However, the
highest yields of 1-acyloxygermatranes were obtained
by carrying out the reaction in acetonitrile, especially
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Table 1. Yields of 1-acyloxygermatranes RCOOGe(OCH2CH2)3N in reaction of 1-germatranol hydrate 1 with carboxylic acids
REACTION OF 1-GERMATRANOL HYDRATE WITH CARBOXYLIC ACIDS
Comp. no.
R
Reaction conditions
CH3CN, 80°С, 6 h
Yield,a %
2
ClCH2
90.8b
CH3CN, 80°С, 12 h
92.4b
3
trans-C6H5CH=CH
iso-С5Н11OH, 130°С, 6 h
iso-С5Н11OH, 130°С, 15 h
CH3OH, 64°С, 3 h
59.3
72.9
11.3
57.0b
6.9
CH3OH, 64°С, 3 h
CH3ОН–Н2О (9 : 1 v/v), 64°С, 3 h
CH3ОН–Н2О (9 : 1 v/v), 64°С, 3 h
CH3CN, 80°С, 6 h
29.5b
90.9b
4
5
C6H5
iso-С5Н11OH, 130°С, 1 h
CH3OH, 64°С, 7 h
CH3CN, 80°С, 1 h
82.0 [12]
31.6
93.5b
2-FC6H4
CH3CN, 80°С, 2 h
CH3CN, 80°С, 4 h
CH3CN, 80°С, 6 h
18.9
53.2
99.6b
6
7
3-BrC6H4
CH3CN, 80°С, 6 h
96.0b
3-HOC6H4
о-С6Н4(СН3)2, 143°С, 7 h
о-С6Н4(СН3)2, 143°С, 10 h
iso-С5Н11OH, 130°С, 3 h
iso-С5Н11OH, 130°С, 6 h
iso-С5Н11OH, 130°С, 12 h
81.2
98.3
59.8
88.9
96.9
8
3-C2H5OC6H4
о-С6Н4(СН3)2, 143°С, 17 h
iso-С5Н11OH, 130°С, 3 h
iso-С5Н11OH, 130°С, 12 h
CH3CN, 80°С, 7 h
44.9
47.0
79.3
89.0
93.2b
CH3CN, 80°С, 7 h
a
Calculated from integral intensities of the OCH2 and NCH2 group protons in 1H NMR spectra of the reaction mixtures. b Dried reaction
mixture kept for 1 h at 50°С in a vacuum of 2 mmHg.
when the dry residue after the reaction was heated in a
vacuum. The reaction between 1-germatranol hydrate
1 and cinnamic acid in boiling acetonitrile for 6 h with
subsequent exposure of the dry reaction residue for 1 h
at 50°С to the vacuum of 2 mmHg gives product 3 in
90.9% yield (Table 1). The reaction of 1 with 3-ethoxy-
benzoic acid in acetonitrile after 7 h of reflux gives the
yield of 89.0%, whereas after exposure of the dry
reaction residue to a vacuum at 50°С the yield reaches
93.2%.
The reaction of 1-germatranol with cinnamic acid
in protic solvent methanol at reflux in the course of 3 h
leads to the formation of only 11.3% of 1-(benzyl-
ideneacetato)germatrane 3. Along with this, 1-meth-
oxygermatrane 10 (7.6%) and bis(germatran-1-yl)-
oxane 11 (4.2%) are formed [schemes (2a)–(2d)].
Earlier it was established that direct reaction of 1
and 11 with methanol follows equations (2b) and (2c)
[13]. It is hardly probable that under these conditions
bis(germatran-1-yl)oxane 11 is formed also due to
elimination of water molecule from two molecules of
1. The latter reaction proceeds only on heating 1 to
220°С in a vacuum [14].
Carrying out the reaction with heating of the
reaction residue in a vacuum turned out to be effective
also for other acids (Table 1). Under these conditions,
the yields in all cases exceed 90%, and with 2-
fluorobenzoic acid 1-(2'-fluorobenzoyloxy)germatrane
5 is formed in quantitative yield and does not require
additional purification.
In the system methanol–water (9 : 1 v/v) the yield
of product 3 is twice as low as in nonaqueous
methanol. The content of 1-methoxygermatrane 10 and
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BARYSHOK, LE
Table 2. Melting points and elemental analysis data of 1-acyloxygermatranes RC(O)OGe(OCH2CH2)3N
Found, %
Ge
30.50 4.33 23.05 4.81 C8H14ClGeNO5 30.77 4.52 23.25 4.49
48.56 4.97 19.42 4.04 C15Н19GeNО5 49.23 5.23 19.84 3.83
Calculated, %
Comp.
no.
mp, °С
(acetonitrile)
R
Formula
C
H
N
С
Н
Ge
N
2
3
5
6
7
8
ClCH2
178–180
trans-C6H5CH=CH 189–190
2-FC6H4
225–227
179–181
222–223а
127–129b
43.74 4.11 19.84 4.04 C13H16FGeNО5 43.63 4.51 20.29 3.91
37.12 3.60 16.89 3.49 C13H16BrGeNО5 37.28 3.85 17.34 3.34
3-BrC6H4
3-HOC6H4
3-C2H5OC6H4
44.27 4.60 19.92 3.88 C13H17GeNО6
43.87 4.81 20.40 3.94
–
–
–
–
C15H21GeNО6
–
–
–
–
а From isopentanol. b From chloroform.
PhCH=CHC(O)OH
N(CH2CH2O)3GeOH
N(CH2CH2O)3GeOCCH=CHPh + H2O,
(2a)
(2b)
O
1
3
CH3OH
,
N(CH2CH2O)3GeOH
N(CH2CH2O)3GeOCH3 + H2O
1
10
,
[N(CH2CH2O)3Ge]2O + CH3OH
(2c)
(2d)
1 + 10
11
1
.
N(CH2CH2O)3GeOCCH=CHPh
11 + PhCH=CHC(O)OH
O
3
bis(germatran-1-yl)oxane 11 (2.0%) in the reaction
mixture is also notably decreased. Probably the
presence of water in methanol shifts the equilibrium of
esterification of 1 to the left [schemes (2а), (2b)]. Note
that unlike their germatrane analogs, 1-acyloxysila-
tranes are much less hydrolytically stable than 1-
alkoxysilatranes [15].
In the IR spectra of compounds 2–8 the absorption
bands νGe–О–C, νС–О–С (1000–1010, 1020–1060, 1080–
1110); νС=О (1640–1680) are present. The band of
stretching vibrations of the OH group in 7 appears at
3240 cm–1.
Therefore, an efficient method of esterification of
1-germatranol with carboxylic acids allowing the
preparation 1-acyloxygermatranes in high yields was
developed.
Keeping the solid reaction mass obtained from the
reaction of 1-germatranol with cinnamic acid in aqueous
methanol to constant mass in a vacuum of 2 mmHg at
40–50°С increases the yield of 3 more than four times
(Table 1), apparently due to elimination of water.
EXPERIMENTAL
IR spectra were recorded on a Bruker Vertex-70
1
spectrometer in microlayer and in KBr. Н and 13С
1-Acyloxygermatranes 2–8 are soluble in aceto-
nitrile and lower alcohols, insoluble in diethyl ether,
alkanes. Their structure was proved by elemental
NMR spectra were registered on a Bruker DPX-400
instrument (400.13 and 101.62 MHz respectively) in
DMSO-d6 (internal reference CH3CN). Elemental
analysis was performed on a Thermo Finigan FlashEA
1
analysis (Table 2), Н, 13С NMR, and IR spectra
(Table 3).
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REACTION OF 1-GERMATRANOL HYDRATE WITH CARBOXYLIC ACIDS
Table 3. Data of 1H, 13C, and IR spectroscopy of 1-acetoxygermatranes 2–8
Comp.
no.
δН, ppm (J, Hz)
δС, ppm
ν, cm–1
3
2
2.99 t (6Н, NCH2, JHH 5.7), 3.74 t (6Н, 51.07 (NCH2), 56.79 (OCH2), 42.78 (CH2Cl), 1728 v.s
OCH2, 3JHH 5.7), 4.16 s (2Н, СН2Cl)
166.32 (C=O)
3
3
2.99 t (6Н, NCH2, JHH 5.6), 3.75 t (6Н, 51.12 (NCH2), 56.67 (OCH2), 121.79 1659 v.s
OCH2, JHH 5.6), 6.45 d (1H, CH=CH), (PhCH=CH), 127.92 (Сm), 128.85 (Сп), 129.77 1622 w
7.38~7.65 m (5Н, С6Н4СН=СН)
3
(СНо), 134.58 (Сipso), 142.29 (PhCH=CH), (CH=CH)
165.86 (С=О)
3
4
5
6
3.01 t (6Н, NCH2, JHH 5.6), 3.77 t (6Н, 51.16 (NCH2), 56.76 (OCH2), 128.28 (CHm), 1660 v.s
OCH2, JHH 5.6), 7.44 t (2Н, СНm, JHH 7.4), 129.24 (CHо), 131.89 (Cipso), 132.04 (Сп), 167.39
3
3
7.55 t (1Н, СНп, JHH 7.2), 7.87 d (2Н, СНо, (C=O)
3
3JHH 7.2)
3
3.01 t (6Н, NCH2, JHH 5.6), 3.77 t (6Н, 51.12 (NCH2), 56.75 (OCH2), 116.52–116.74 1683 v.s
OCH2, 3JHH 5.6), 7.21~7.76 m (4Н, С6Н4)
(Cm), 121.61–121.70 (Cipso), 124.07 (Cо), 131.73
(Cp), 133.57–133.65 (Cо), 159.50–162.04 (Cо),
163.09 (С=О)
3
3.02 t (6Н, NCH2, JHH 5.5), 3.78 t (6Н, 51.10 (NCH2), 56.78 (OCH2), 121.45 (Cipso), 1687 v.s
OCH2, JHH 5.6), 7.44 t (1Н, СНm, JHH 7.9), 128.27 (Cо), 130.68 (Cm), 131.74 (Cо), 134.80
3
3
7.77 d (1Н, СНп, 3JHH 7.7), 7.85 d (1Н, СНо, (Cp), 135.15 (Cm), 163.97 (С=О)
3JHH 7.7), 7.95 s (1Н, СН2)
3
7
8
3.00 t (6Н, NCH2, JHH 5.3), 3.80 t (6Н, 51.13 (NCH2), 56.72 (OCH2), 116.00 (Cp), 1668 s, 1682 v.s
OCH2, JHH 5.3), 9.57 s (ОН), 6.90~7.30 m 119.04 (Cо), 120.09 (Cm), 129.24 (Cо), 134.24 3370 (OH)
3
(4Н, С6Н4)
(Cipso), 157.21 (Cm), 165.49 (C=O)
3
3.01 t (6Н, NCH2, JHH 5.6), 3.77 t (6Н, 14.56 (CH3), 51.13 (NCH2), 56.72 (OCH2), 63.15 1683 v.s
OCH2, JHH 5.6), 1.33 t (3Н, СН3, 3JHH 6.9), (OCH2CH3), 114.63 (Со), 118.35 (Со), 121.52 (Сm),
3
4.04 q (2Н, ОСН2СН3, JHH 6.9), 7.09~7.45 129.35 (Сп), 134.35 (Cipso), 158.32 (COC2H5),
3
m (4Н, С6Н4)
165.24 (C=O)
1112 gas analyzer. Melting points were determined on
a Micro-Hot-Stage PolyTherm A unit.
chloroacetic acid (hereinafter the composition of the
reaction residue is given in molar % estimated from
the integral intensity of signals in the 1H NMR
spectra). The increased time of heating to 12 h led to
the following composition of the reaction residue:
85.5% of 2, 7.0% of 1 and 7.5% of chloroacetic acid.
Crystallization from acetonitrile gave 0.950 g (77.2%)
of 2.
Solvents (diethyl ether, acetonitrile, methanol, iso-
pentanol, о-xylene) were dried by the known proce-
dures [16]. Germanium dioxide, chloroacetic, cin-
namic, benzoic, 2-fluoro-, 3-bromo-, 3-hydroxy- and
3-ethoxybenzoic acid of analytical grade were used
without additional purification. 1-Hydroxygermatrane
hydrate 1 was synthesized from germanium dioxide and
triethanolamine by the procedure described in [17].
1-(Benzylideneacetato)germatrane (3). а. The solu-
tion of 1.0 g (3.940 mmol) of 1, 0.584 g (3.94 mmol)
of cinnamic acid in 40 mL of isopentanol was heated
to reflux with the Dean-Stark trap for 6 h, the solvent
was removed at 130°С to the residual volume ~5 mL,
the concentrate was cooled to 25°С, 10 mL of dry
diethyl ether was added and the mixture was left to
stay overnight. The formed precipitate was filtered off,
washed with dry diethyl ether (2 × 10 mL), and dried
for 2 h at 25°С in a vacuum of 2 mmHg. 1.44 g of
colorless product was obtained containing (from the
1-(Chloroacetoxy)germatrane (2). The solution of
1.0 g (3.94 mmol) 1, 0.372 g (3.94 mmol) of
chloroacetic acid in 40 mL of acetonitrile were heated
at reflux for 6 h, the solvent was removed at 80°С to
the residual volume of 2–3 mL. The remained aceto-
nitrile and the formed water were removed in a
vacuum (2 mmHg). Colorless solid residue was kept in
the same vacuum at 50°С for 1 h to obtain 1.203 g of
colorless solid compound consisting of 83.4% of 1-
(chloroacetoxy)germatrane 2, 8.5% of 1 and 8.1% of
1
data of Н NMR spectra in the mixture DMSO-d6 :
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BARYSHOK, LE
CCl4, 1 : 1) 50.6% of 1-(benzylideneacetato)germa-
trane 3, 5.1% of 1-isoamyloxygermatrane 9, 26.5% of
1, 3.2% of bis(germatran-1-yl)oxane 11, and 14.6% of
cinnamic acid. The increased time of heating to 15 h
resulted ine the reaction mixture of the following
composition (from 1H NMR spectra): 66.3% of 3, 5.5%
of 9, 17% of 1, 2.2% of 11, and 9% of cinnamic acid.
b. The solution of 1.0 g (3.940 mmol) of 1 and
0.481 g (3.940 mmol) of benzoic acid in 20 mL of
methanol was refluxed for 7 h, methanol and the
formed water were removed in a vacuum of 2 mmHg
to obtain 1.17 g of colorless precipitate of the
following composition: 18.7% of 3, 40.5% of 1, 1.6%
of 11 and 39.2% of benzoic acid.
b. The solution of 0.5 g (2.121 mmol) of 1, 0.314 g
(2.121 mmol) of cinnamic acid in 5 mL of methanol
was heated to reflux for 3 h, the methanol and the
formed water were removed in a vacuum (2 mmHg) to
give 0.74 g of viscous mass consisting according to the
1Н NMR data of 6% of 3, 4.1% of 1-methoxyger-
matrane 10, 40.7% of 1, 2.5% of 11, and 46.7% of
cinnamic acid. After additional keeping the residue in
a vacuum of 2 mmHg at 50°С for 1 h the composition
changed to 3 : 10 : 1 : 11 : cinnamic acid = 39.3 : 9.5 :
18.2 : 2.0 : 31.0.
c. The mixture of 0.5 g (0.197 mmol) of 1 and
0.240 g (0.197 mmol) of benzoic acid in 5 mL of
acetonitrile was refluxed for 1 h, the solvent and the
formed water were removed in a vacuum of 2 mmHg.
The colorless solid residue was kept in the same
vacuum at 50°С for 1 h to obtain 1.203 g of colorless
solid compound consisting of 88.6% of 4, 6.2% of 1
and 5.2% of benzoic acid.
1-(2'-Fluorobenzoyloxy)germatrane (5). The solu-
tion of 1.0 g (3.940 mmol) of 1, 0.552 g (3.940 mmol)
of 2-fluorobenzoic acid in 40 mL of acetonitrile was
refluxed. After 2 and 4 h the samples of 0.5 mL of the
solution were taken for monitoring the reaction
c. The solution of 0.314 g (2.121 mmol) of
cinnamic acid and 0.5 g (2.121 mmol) of 1 in 5 mL of
the mixture МеОН–Н2О (9 : 1 v/v) was refluxed for
3 h. After removal of methanol and the formed water
in a vacuum of 2 mmHg 0.8 g of colorless residue was
obtained having the following composition: 3 : 10 : 1 :
11 : cinnamic acid = 3.5 : 4.8 : 41.6 : 0.9 : 49.2. After
additional keeping this residue in a vacuum of
2 mmHg at 50°С for 1 h its composition changed to 3 :
10 : 1 : 11 : cinnamic acid = 17.8 : 0.6 : 40.7 : 1.1 : 39.7.
1
progress by Н NMR spectroscopy. After 2 h the
mixture contained 10.5% of 1-(2'-fluorobenzoyloxy)
germatrane 5, 44.3% of 1, and 45.2% of 2-fluoro-
benzoic acid; after 4 h 36.6% of 5, 31.2% of 1, and
32.2% of 2-fluorobenzoic acid. After 6 h acetonitrile
was removed at 80°С to the beginning of formation of
crystals, cooled, the formed crystalline precipitate was
separated by decantation and kept at 2 mmHg at 50°С
for 1 h. The yield of 1-(2'-fluorobenzoyloxy)germatrane
5 was 1.303 g (92.4%). After evaporation of the
mother liquor to dryness and keeping in a vacuum of
2 mmHg at 50°С for 1 h additional 0.102 g (7.2%) of 5
with mp 223–226°С was obtained.
d. The solution of 1.0 g (3.940 mmol) of 1, 0.584 g
(3.940 mmol) of cinnamic acid in 40 mL of acetonitrile
was refluxed for 6 h, the solvent was removed to the
residual volume of 2–3 mL. The remained acetonitrile
and the formed water were removed in a vacuum of
2 mmHg to the formation of colorless solid residue.
After exposure of this residue to the same vacuum at
50°С for 1 h 1.450 g of the mixture was obtained
containing 81.7% of 3, 4.4% of 1, 10.1% of cinnamic
acid and 3.8% of 11. Cinnamic acid was removed by
treating the mixture with anhydrous diethyl ether and
decantation. The crystallization of the dry residue from
acetonitrile gave 1-(benzylideneacetato)germatrane 3
in 1.18 g (81.8%) yield as colorless needle crystals.
1-(3'-Bromobenzoyloxy)germatrane (6). The solu-
tion of 1.0 g (3.940 mmol) of 1, 0.792 g (3.940 mmol)
of 3-bromobenzoic acid in 40 mL of acetonitrile was
refluxed for 6 h, the solvent was removed at 80°С to
the residual volume 2–3 mL. The remained acetonitrile
and the formed water were removed in a vacuum of
2 mmHg. Colorless solid residue was kept in the same
vacuum at 50°С for 1h. It consisted of 93.3% of 1-(3'-
bromobenzoyloxy)germatrane 6, 3.1% of 1, 0.7% of
bis(germatran-1-yl)oxane 11, and 2.8% of 3-bromo-
benzoic acid. Crystallization from acetonitrile gave
1.485 g (90.0%) of colorless crystals of 6.
1-Benzoyloxygermatrane (4). а. After refluxing
for 1 h of 1.221 g (0.01 mol) of benzoic acid and 2.538 g
(0.01 mol) of 1 in 50 mL of isoamyl alcohol with
azeotropic distillation of water and subsequent
treatment of the reaction mixture as described above
2.78 g (82.0%) of 1-benzoyloxygermatrane 4 was
obtained. mp 257–262°С. Literature: mp 257–260°С [12].
1-(3'-Hydroxybenzoyloxy)germatrane (7). а. The
solution of 0.750 g (2.954 mmol) of 1, 0.430 g
(3.113 mmol) of 3-hydroxybenzoic acid in 120 mL of
dry о-xylene was heated with the Dean-Stark trap at
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REACTION OF 1-GERMATRANOL HYDRATE WITH CARBOXYLIC ACIDS
142°С for 7 h, then a sample of 1 mL was taken, the
solvent was removed, washed with dry diethyl ether,
and dried in a vacuum of 2 mmHg for 1 h. 0.02 g of a
solid residue was obtained consisting of 69.6% of 1-
(3'-hydroxybenzoyloxy)germatrane 7, 14.4% of 1, and
16.1% of unreacted acid. The reaction mixture was
refluxed for 10 h, the precipitate formed upon cooling
was filtered off, washed with diethyl ether, and dried
removed in a vacuum of 2 mmHg to obtain a viscous
residue consisting of 79.5% of 8, 9.8% of 1, and 10.7%
of m-ethoxybenzoic acid. After keeping in a vacuum of
2 mmHg at 50°С for 1 h 1.513 g of a paste-like mass
was obtained, which solidified after 2 days. The
composition was as follows: 86.2% of 8, 6.3% of 1,
and 7.6% of m-ethoxybenzoic acid. Crystallization from
chloroform gave 1.22 g (80.6%) of 8 containing 1.5%
of 1.
1
in a vacuum of 2 mmHg for 1 h. According to Н
NMR spectrum (DMSO-d6) the residue consisted of
98.3% of 7 and 1.7% of 1. The crystallization from
acetonitrile gave 0.980 g (93.5%) of 7 with mp 222–
223°С.
REFERENCES
1. Lukevics, E. and Ignatovich, L., The Chemistry of
Organic Germanium, Tin and Lead Compounds, New
York: Wiley, 2002, vol. 2, p. 1653.
b. The solution of 1.0 g (3.940 mmol) of 1, 0.544 g
(3.940 mmol) of 3-hydroxybenzoic acid in 40 mL of
isoamyl alcohol was refluxed with the Dean-Stark trap.
To monitor the reaction, 1 mL of the solution was
taken off after 3 and 6 h of heating, the solvent was
removed, the residue was washed with dry ether and
dried in a vacuum of 2 mmHg for 1 h. From the data of
1Н NMR, after 3 h the residue contained 43.2% of 7,
27.8% of 1, and 29.0% of 3-hydroxybenzoic acid, and
after 6 h, 80.5% of 7, 9.4% of 1, and 10.1% of 3-
hydroxybenzoic acid. After 12 h of reflux 1.2 g of the
residue was obtained containing 94.0% of 7, 3.0% of 1
and 3.0% of 3-hydroxybenzoic acid. The reaction
mixture was washed with dry acetonitrile (3 × 10 mL),
kept in a vacuum of 2 mmHg for 1 h to obtain 1.120 g
(79.9%) of fine-crystalline germatrane 7 with mp 221–
222°С. Found, %: C 44.31, H 4.92, N 3.97, Ge 19.88.
C13H17NGeO6. Calculated, %: C 43.87, H 4.81, N 3.94,
Ge 20.40.
2. Garabadzhiu, A.V., Voronkov, M.G., Nyanikova, G.G.,
Samokhin, G.S., Vrazhnov, D.V., and Kochina, Т.А.,
Dokl. Biol. Sci., 2011, vol. 439, p. 264.
3. RF Patent 2233286, 1998; freepatent.ru/patents/2233286.
4. RF Patent 2333912, 2006; Bull. Izobret., 2008, no. 26.
5. RF Patent 2293086, 2007; Bull. Izobret., 2007, no. 4.
6. Bashkirova, S.A., Doskoch, Ya.E., Bessonov, A.E.,
Berezovskaya, I.V., and Kalmykova, E.A., Spravochnik
vracha obshchei praktiki (Handbook of General Prac-
titioner), 2009, no. 9, p. 61.
7. Korolev, Yu.M. and Bashkirova, S.А., Dokl. Phys.
Chem. 2010, vol. 435, no. 2, p. 205.
8. Gar, T.K., Khromova, N.Yu., Sonina, N.V., Nikitin, V.P.,
Polyakova, M.V., and Mironov, V.F., Zh. Obsch. Khim.,
1979, vol. 49, no. 7, p. 1516.
9. Gar, T.K., Khromova, N.Yu., Tandura, S.N., and
Mironov, V.F., Zh. Obsch. Khim., 1983, vol. 53, no. 6,
p. 1800.
10. Zaitseva, G.S., Livantsova, L.I., Nasim, M., Karlov, S.S.,
Churakov, A.V., Howard, J.A.K., Avtomonov, E.V.,
and Lorberth, J., Chem. Ber. Recueil., 1997, vol. 130,
p. 739.
11. Jing, L., Qinglan, X., Jitao, W., Hua, L., Honggen, H.,
and Xinkan, Y., Guangdong Weiliang Yuansu Kexue,
1998, vol. 5, no. 2, p. 26.
1-(3'-Ethoxybenzoyloxy)germatrane (8). а. From
1.0 g (3.940 mmol) of 1, 0.655 g (3.940 mmol) of m-
ethoxybenzoic acid in 150 mL of о-xylene after reflux
for 17 h was obtained 1.507 g of the product contain-
ing 29.8% of 1-(3'-ethoxybenzoyloxy)germatrane 8,
36.5% of 1-germatranol 1, and 33.6% of unreacted acid.
12. Baryshok, V.P., Le, N.T.Z., and Voronkov, M.G., Russ.
J. Gen. Chem., 2013, vol. 83, no. 10, p. 1965.
13. Le, N.T.Z., Baryshok, V.P., and Voronkov, M.G.,
Butlerov Comm., 2013, vol. 36, no. 10, p. 57.
14. Mironov, V.F., Metallorg. Khim., 1993, vol. 6, no. 2,
b. A mixture of 1.0 g (3.940 mmol) of 1, 0.655 g
(3.940 mmol) of m-ethoxybenzoic acid in 40 mL of
isoamyl alcohol was refluxed with the Dean-Stark trap.
The yield of 1-(3'-ethoxybenzoyloxy)germatrane 8
after 3 and 12 h of reflux was 47.0% and 79.3%,
respectively.
p. 243.
15. Voronkov, M.G., Pure Appl. Chem., 1969, vol. 13,
p. 35.
c. A mixture of 1.0 g (3.940 mmol) of 1, 0.655 g
(3.940 mmol) of m-ethoxybenzoic acid in 40 mL of
acetonitrile was refluxed for 7 h. Acetonitrile was
removed at 80°С to the volume of 2–3 mL. The
remained acetonitrile and the formed water were
16. Laboratornaya tekhnika organicheskoi khimii (Labora-
tory Techniques in Organic Chemistry), Keil, B.M.,
Ed., Мoscow: Mir, 1966, p. 210.
17. Voronkov, M.G., Ovchinnikova, Z.A., and Baryshok, V.P.,
Izv. Akad. Nauk SSSR, Ser. Khim., 1987, no. 4, p. 880.
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