Functionally substituted aromatic schiff bases containing pyrrole and carborane fragments

Article abstract of DOI:10.1134/S1070428010010057

Functionally substituted aromatic Schiff bases containing pyrrole and carborane fragments were synthesized by condensation of substituted benzaldehydes of the vanillin series with 2-(2-methyl-1 H-pyrrol-1- yl)ethanamine and N-(3-aminophenyl)-o-carborane-1

Full text of DOI:10.1134/S1070428010010057

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2010, Vol. 46, No. 1, pp. 59–63. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © E.A. Dikusar, V.I. Potkin, R.A. Gadzhily, Sh.F. Nagieva, A.A. Mamedova, M.P. Bei, A.P. Yuvchenko, 2010, published in Zhurnal
Organicheskoi Khimii, 2010, Vol. 46, No. 1, pp. 59–63.
Functionally Substituted Aromatic Schiff Bases Containing
Pyrrole and Carborane Fragments
E. A. Dikusara, V. I. Potkina, R. A. Gadzhilyb, Sh. F. Nagievab, A. A. Mamedovab,
M. P. Beic, and A. P. Yuvchenkoc
a Institute of Physical Organic Chemistry, National Academy of Sciences of Belarus,
ul. Surganova 13, Minsk, 220072 Belarus
e-mail: potkin@ifoch.bas-net.by
b Institute of Polymeric Materials, National Academy of Sciences of Azerbaidjan, Sumgait, Azerbaidjan
c Institute of New Materials Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
Received November 26, 2008
Abstract—Functionally substituted aromatic Schiff bases containing pyrrole and carborane fragments were
synthesized by condensation of substituted benzaldehydes of the vanillin series with 2-(2-methyl-1H-pyrrol-1-
yl)ethanamine and N-(3-aminophenyl)-o-carborane-1-carboxamide.
DOI: 10.1134/S1070428010010057
Derivatives of nitrogen-containing polyhedral car-
borane cluster systems attract interest as substrates for
pharmacokinetic studies in the field of boron neutron-
capture therapy of cancer and radionuclide diagnostics
and therapy [1–6]. It is also known that Schiff bases
derived from substituted benzaldehydes of the vanillin
series exhibit biological activity [7, 8].
ments (IIIe, IIIh, VIb–VIe, VIh, VIi) by condensa-
tion of substituted benzaldehydes Ia–Ii of the vanillin
series with 2-(2-methyl-1H-pyrrol-1-yl)ethanamine
(II) and N-(3-aminophenyl)-o-carboranecarboxylic acid
(V) in boiling anhydrous methanol (Schemes 1, 2). The
reactions were complete in 10–15 min under mild con-
ditions in the absence of a catalyst, and compounds III
and VI, including those containing two isomeric ortho-
and meta-carborane clusters in a single molecule (VIe,
VIh) were isolated in 75–85% yield. Mild reaction
The present communication reports on the synthesis
of functionally substituted aromatic Schiff bases con-
taining pyrrole (IIIa–IIId, IIIf) and carborane frag-
Scheme 1.
CHO
NH2
N
N
N
+
R'O
R'O
Me
Me
OR
RO
Ia–Ih
II
IIIa–IIIh
O
O
Cl
C
R = Me, R′ = H (a), MeC(O) (b), PhC(O) (c), 4-BrC6H4C(O) (d),
(e),
(f);
N
Cl
C
S
H
O
C
R = Et, R′ = H (g),
(h).
C
H
59

DIKUSAR et al.
60
Scheme 2.
O
O
CHO
N
N
C
C
H
+
N
HC
HC
R'O
H
R'O
H2N
OR
OR
Ib–Ie, Ih, Ii
V
VIb–VIe, VIh, VIi
O
O
C
C
R = Me, R′ = MeC(O) (b), PhC(O) (c), 4-BrC6H4C(O) (d),
(e); R = Et, R′ =
(h),
C
C
H
H
Me(CH2)8CO (i).
conditions favored conservation of labile ester groups
in the product molecules. However, our attempts to
synthesize 4,5-dichloroisothiazole-3-carboxylic acid
derivative IIIf according to the same procedure were
poorly effective. The reaction was accompanied by
strong tarring, presumably due to replacement of
chlorine atoms in the isothiazole fragment; compound
IIIf was isolated in ~7% yield. The latter was synthe-
sized in a higher yield (50%) by reaction of Schiff base
IIIa having a phenolic hydroxy group with 4,5-di-
chloroisothiazole-3-carbonyl chloride (IV) in the pres-
ence of pyridine (Scheme 3).
using tetramethylsilane as internal reference. The mo-
lecular weights of compounds IIIb–IIId and IIIf were
determined by cryoscopy in benzene; molecular
weights of IIIa, IIIe, IIIh, V, VIb–VIe, VIh, and VIi
were not determined because of their poor solubility in
benzene. Initial esters I were synthesized according to
the procedures described in [10–14]; 2-(2-methyl-1H-
pyrrol-1-yl)ethanamine (II) [15], 4,5-dichloroisothia-
zole-3-carbonyl chloride (IV) [16], and o-carborane-1-
carboxylic acid (VII) [17] were prepared by known
methods.
Schiff bases IIIa–IIIe, IIIh, VIb–VIe, VIh, and
VIi (general procedure). A solution of 5 mmol of the
corresponding aromatic aldehyde I and 5 mmol of
amine II or V in 30 ml of anhydrous methanol was
heated for 15 min under reflux. The mixture was fil-
tered while hot, and the filtrate was cooled and left to
stand for 10–15 h at 5°C. The precipitate was filtered
off through a glass filter, washed with methanol, and
dried in air.
Scheme 3.
O
Cl
Cl
Pyridine
IIIa
+
IIIf
N
Cl
S
IV
2-Methoxy-4-[(E)-{[2-(2-methyl-1H-pyrrol-1-yl)-
ethyl]imino}methyl]phenol (IIIa). Yield 78%,
mp 184–185°C (from MeOH). IR spectrum, ν, cm–1:
3287 (OH); 3070, 3043, 3004 (C–Harom); 2947, 2922,
2853 (C–Haliph); 1610 (C=N); 1596, 1519, 1469
(C=Carom); 1279, 1247, 1162, 1032 (C–O); 878, 822,
The structure of compounds IIIa–IIIh, VIb–VIe,
VIh, and VIi was confirmed by their elemental anal-
1
yses and IR and H NMR spectra. According to the
1H NMR data, the isolated products contained 94±1%
1
of the main substance. Comparison of their H NMR
spectra with those reported previously for structurally
related compounds [9] indicated E configuration of the
azomethine fragment.
1
780, 758, 742 (δC–Harom). H NMR spectrum, δ, ppm:
2.23 s (3H, Me), 3.30–3.95 m (4H, CH2), 3.85 s (3H,
MeO); 4.97 s, 5.50 m, and 5.80 m (3H, CH, pyrrole);
6.60 br.s (1H, OH), 6.88 s (2H, Harom), 6.99 s (1H,
EXPERIMENTAL
H
arom), 7.26 s (1H, CH=N). Found, %: C 70.08;
H 7.19; N 10.59. C15H18N2O2. Calculated, %: C 69.75;
H 7.02; N 10.84.
The IR spectra were recorded in KBr on a Nicolet
Protégé-460 spectrometer with Fourier transform. The
1H NMR spectra were measured on a Tesla BS-587A
instrument at 100 MHz from 2% solutions in CDCl3
2-Methoxy-4-[(E)-{[2-(2-methyl-1H-pyrrol-1-yl)-
ethyl]imino}methyl]phenyl acetate (IIIb). Yield
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 1 2010

FUNCTIONALLY SUBSTITUTED AROMATIC SCHIFF BASES
61
85%, mp 45–46°C (from MeOH). IR spectrum, ν,
cm–1: 3098, 3054, 3003 (C–Harom); 2958, 2935, 2838
(C–Haliph); 1763 (C=O); 1610 (C=N); 1605, 1509,
1464, 1450 (C=Carom); 1271, 1216, 1196, 1154, 1119,
1033 (C–O); 902, 860, 833, 738, 702 (δC–Harom).
1H NMR spectrum, δ, ppm: 2.24 s (3H, Me), 2.34 s
(3H, MeCO), 3.30–3.90 m (4H, CH2), 3.89 s (3H,
MeO); 4.97 s, 5.50 m, and 5.80 m (3H, CH, pyrrole);
6.89 s (2H, Harom), 6.99 s (1H, Harom), 7.29 s (1H,
CH=N). Found, %: C 68.23; H 6.78; N 9.04. M 288.5.
C17H20N2O3. Calculated, %: C 67.98; H 6.71; N 9.33.
M 300.4.
pyrrole); 6.82–7.00 m (3H, Harom), 7.30 s (1H, CH=N).
Found, %: C 50.87; H 6.64; B 24.83; N 6.25.
C18H28B10N2O3. Calculated, %: C 50.45; H 6.59;
B 25.23; N 6.54.
2-Ethoxy-4-[(E)-{[2-(2-methyl-1H-pyrrol-1-yl)-
ethyl]imino}methyl]phenol (IIIg). Yield 75%,
mp 182– 183°C (from MeOH). IR spectrum, ν, cm–1:
3274 (OH); 3095, 3055, 3030, 3003 (C–Harom); 2983,
2968, 2945, 2923, 2873 (C–Haliph); 1610 (C=N); 1597,
1531, 1473, 1449 (C=Carom); 1271, 1234, 1166, 1138,
1048 (C–O); 860, 845, 825, 809, 780, 738 (δC–Harom).
1H NMR spectrum, δ, ppm: 1.42 t (3H, Me), 2.23 s
(3H, Me), 3.10–3.95 m (4H, CH2), 4.08 q (2H, OCH2);
4.98 s, 5.48 m, and 5.82 m (3H, CH, pyrrole); 6.62 br.s
(1H, OH), 6.89 s (2H, Harom), 6.96 s (1H, Harom), 7.26 s
(1H, CH=N). Found, %: C 70.93; H 7.56; N 9.87.
C16H20N2O2. Calculated, %: C 70.56; H 7.40; N 10.29.
2-Methoxy-4-[(E)-{[2-(2-methyl-1H-pyrrol-1-yl)-
ethyl]imino}methyl]phenyl benzoate (IIIc). Yield
84%, mp 60–61°C (from MeOH). IR spectrum, ν,
cm–1: 3097, 3061, 3003 (C–Harom); 2957, 2934, 2838
(C–Haliph); 1736 (C=O); 1610 (C=N); 1604, 1510,
1462, 1451 (C=Carom); 1269, 1200, 1154, 1120, 1062,
1024 (C–O); 871, 860, 815, 747, 709 (δC–Harom).
1H NMR spectrum, δ, ppm: 2.25 s (3H, Me), 3.30–
3.90 m (4H, CH2), 3.90 s (3H, MeO); 4.98 s, 5.50 m,
and 5.82 m (3H, CH, pyrrole); 7.05–8.16 m (8H,
Harom), 7.31 s (1H, CH=N). Found, %: C 73.25;
H 6.19; N 7.44. M 350.3. C22H22N2O3. Calculated, %:
C 72.91; H 6.12; N 7.73. M 362.4.
2-Ethoxy-4-[(E)-{[2-(2-methyl-1H-pyrrol-1-yl)-
ethyl]imino}methyl]phenyl 1,7-dicarba-closo-
dodecaborane(12)-1-carboxylate (IIIh). Yield 77%,
mp 58–59°C (from MeOH). IR spectrum, ν, cm–1:
3100, 3064, 3032, 3002 (C–Harom, C–Hcarb); 2981,
2970, 2945, 2934, 2900, 2874 (C–Haliph); 2608 (B–H);
1748 (C=O); 1610 (C=N); 1599, 1508, 1449, 1452
(C=Carom); 1271, 1193, 1166, 1120, 1047 (C–O); 859,
838, 820, 806, 785, 760, 752, 737, 627 (δC–Harom
δC–Hcarb). H NMR spectrum, δ, ppm: 1.44 t (3H,
,
2-Methoxy-4-[(E)-{[2-(2-methyl-1H-pyrrol-1-yl)-
ethyl]imino}methyl]phenyl 4-bromobenzoate (IIId).
Yield 82%, mp 51–52°C (from MeOH). IR spectrum,
ν, cm–1: 3089, 3069, 3034, 3003 (C–Harom); 2950,
2930, 2875, 2852 (C–Haliph); 1739 (C=O); 1610
(C=N); 1605, 1589, 1508, 1483, 1463 (C=Carom); 1262,
1199, 1154, 1120, 1070, 1010 (C–O); 871, 846, 770,
1
Me), 2.23 s (3H, Me), 2.90–3.90 m (5H, CH2, 7-H),
4.08 q (2H, OCH2); 5.09 s, 5.45 m, and 5.82 m (3H,
CH, pyrrole); 6.82–7.04 m (3H, Harom), 7.30 s (1H,
CH=N). Found, %: C 51.93; H 6.85; B 24.05; N 6.20.
C19H30B10N2O3. Calculated, %: C 51.56; H 6.83;
B 24.43; N 6.33.
1
749, 720 (δC–Harom). H NMR spectrum, δ, ppm:
2.25 s (3H, Me), 3.30–3.90 m (4H, CH2), 3.91 s (3H,
MeO); 4.98 s, 5.50 m, and 5.83 m (3H, CH, pyrrole);
7.00–8.25 m (7H, Harom), 7.32 s (1H, CH=N). Found,
%: C 60.08; H 4.86; Br 17.75; N 6.04. M 425.9.
C22H21BrN2O3. Calculated, %: C 59.87; H 4.80;
Br 18.11; N 6.35. M 441.3.
4-[(E)-{3-[1,2-Dicarba-closo-dodecaborane(12)-
1-carbonylamino]phenylimino}methyl]-2-methoxy-
phenyl acetate (VIb). Yield 81%, decomposes above
320°C (from MeOH). IR spectrum, ν, cm–1: 3090,
3070, 3060, 3008 (C–Harom-, C–Hcarb); 2967, 2933,
2885, 2853 (C–Haliph); 2526 (B–H); 1763 (C=O); 1629
(C=N); 1601, 1506, 1464, 1417 (C=Carom); 1271, 1196,
1153, 1119, 1031 (C–O); 904, 860, 840, 777, 750, 740,
2-Methoxy-4-[(E)-{[2-(2-methyl-1H-pyrrol-1-
yl)ethyl]imino}methyl]phenyl 1,7-dicarba-closo-
dodecaborane(12)-1-carboxylate (IIIe). Yield 75%,
mp 52–53°C (from MeOH). IR spectrum, ν, cm–1:
3099, 3070, 3034, 3003 (C–Harom, C–Hcarb); 2959,
2936, 2920, 2875, 2845, (C–Haliph); 2606 (B–H); 1749
(C=O); 1637 (C=N); 1609, 1511, 1463, 1454, 1440
(C=Carom); 1274, 1260, 1196, 1155, 1120, 1065, 1033
(C–O); 860, 835, 815, 780, 760, 750, 728, 625
1
675, 665, 620, 604 (δC–Harom, C–Hcarb). H NMR spec-
trum, δ, ppm: 2.35 s (3H, MeCO), 3.86 s (3H, MeO),
4.06 br.s (1H, 2-H), 6.80–7.50 m (8H, Harom, NH),
8.47 s (1H, CH=N). Found, %: C 50.86; H 6.02;
B 23.38; N 5.84. C19H26B10N2O4. Calculated, %:
C 50.51; H 5.77; B 23.79; N 6.16.
4-[(E)-{3-[1,2-Dicarba-closo-dodecaborane(12)-
1-carbonylamino]phenylimino}methyl]-2-methoxy-
phenyl benzoate (VIc). Yield 80%, mp 205–206°C
(from MeOH). IR spectrum, ν, cm–1: 3090, 3070, 3040,
1
(δC–Harom, δC–Hcarb). H NMR spectrum, δ, ppm:
2.23 s (3H, Me), 2.90–3.90 m (5H, CH2, 7-H), 3.86 s
(3H, MeO); 5.09 s, 5.45 m, and 5.82 m (3H, CH,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 1 2010

DIKUSAR et al.
62
3008 (C–Harom, C–Hcarb); 2968, 2934, 2920, 2870,
2855 (C–Haliph); 2527 (B–H); 1741 (C=O); 1628
(C=N); 1601, 1590, 1507, 1463, 1452 (C=Carom); 1260,
1202, 1177, 1153, 1120, 1059, 1024 (C–O); 880, 800,
778, 740, 707, 682, 670, 622 (δC–Harom, δC–Hcarb).
1H NMR spectrum, δ, ppm: 3.86 s (3H, MeO),
4.06 br.s (1H, 2-H), 6.70–8.50 m (14H, Harom, CH=N,
NH). Found, %: C 56.19; H 5.83; B 20.48; N 5.06.
C24H28B10N2O4. Calculated, %: C 55.80; H 5.46;
B 20.93; N 5.42.
(8H, Harom, NH), 8.48 s (1H, CH=N). Found, %:
C 42.85; H 6.23; B 35.79; N 4.30. C21H36B20N2O4.
Calculated, %: C 42.27; H 6.08; B 36.23; N 4.69.
4-[(E)-{3-[1,2-Dicarba-closo-dodecaborane(12)-
1-carbonylamino]phenylimino}methyl]-2-ethoxy-
phenyl decanoate (VIi). Yield 83%, mp 115–116°C
(from MeOH). IR spectrum, ν, cm–1: 3090, 3070, 3062,
3007 (C–Harom, C–Hcarb); 2964, 2925, 2853 (C–Haliph);
2529 (B–H); 1763 (C=O); 1629 (C=N); 1601, 1590,
1506, 1464, 1417 (C=Carom); 1272, 1198, 1141, 1109,
1032 (C–O); 902, 868, 840, 778, 740, 725, 685, 665,
4-[(E)-{3-[1,2-Dicarba-closo-dodecaborane(12)-
1-carbonylamino]phenylimino}methyl]-2-methoxy-
phenyl 4-bromobenzoate (VId). Yield 81%, mp 168–
169°C (from MeOH). IR spectrum, ν, cm–1: 3094,
3070, 3040, 3006 (C–Harom, C–Hcarb); 2964, 2930,
2870, 2855 (C–Haliph); 2525 (B–H); 1739 (C=O); 1629
(C=N); 1601, 1589, 1506, 1484, 1463 (C=Carom); 1259,
1200, 1151, 1120, 1070, 1010 (C–O); 878, 845, 780,
1
620 (δC–Harom, δC–Hcarb). H NMR spectrum, δ, ppm:
0.92 t (3H, Me), 1.20–1.56 m (12H, CH2), 1.84 m (2H,
MeCH2), 2.65 t (2H, CH2CO), 3.86 s (3H, MeO),
4.06 br.s (1H, 2-H), 6.85–7.50 m (8H, Harom, NH),
8.47 s (1H, CH=N). Found, %: C 57.75; H 7.62;
B 18.69; N 4.70. C27H42B10N2O4. Calculated, %:
C 57.22; H 7.47; B 19.08; N 4.94.
1
748, 700, 682, 628 (δC–Harom, δC–Hcarb). H NMR
2-Methoxy-4-[(E)-{[2-(2-methyl-1H-pyrrol-1-yl)-
ethyl]imino}methyl]phenyl 4,5-dichloro-1,2-thia-
zole-3-carboxylate (IIIf). A suspension of 2 mmol of
compound IIIa, 2 mmol of 4,5-dichloro-1,2-thiazole-
3-carbonyl chloride (IV), and 2 mmol of pyridine in
50 ml of anhydrous benzene was heated for 48 h under
reflux in an argon atmosphere. The resulting solution
was cooled, the precipitate of pyridine hydrochloride
was filtered off, and the filtrate was washed with water
and a 5% solution of NaHCO3. The solvent was
removed, and the residue was purified by low-tempera-
ture crystallization from methanol. Yield 50%, mp 76–
77°C (from MeOH). IR spectrum, ν, cm–1: 3087, 3070,
3037, 3003 (C–Harom); 2960, 2923, 2875, 2855
(C–Haliph); 1754 (C=O); 1647, 1610 (C=N); 1605,
1509, 1465, 1428, 1394 (C=Carom); 1351 (C–C, isothia-
zole); 1273, 1189, 1162, 1120, 1070, 1032 (C–O); 895,
spectrum, δ, ppm: 3.88 s (3H, MeO), 4.07 br.s (1H,
2-H), 6.90–8.50 m (13H, Harom, CH=N, NH). Found,
%: C 48.88; H 4.50; B 17.65; Br 13.04; N 4.28.
C24H27B10BrN2O4. Calculated, %: C 48.41; H 4.57;
B 18.16; Br 13.42; N 4.70.
4-[(E)-{3-[1,2-Dicarba-closo-dodecaborane(12)-
1-carbonylamino]phenylimino}methyl]-2-methoxy-
phenyl 1,7-dicarba-closo-dodecaborane(12)-1-car-
boxylate (VIe). Yield 76%, decomposes above 320°C
(from MeOH). IR spectrum, ν, cm–1: 3090, 3062, 3007
(C–Harom, C–Hcarb); 2959, 2933, 2876, 2853 (C–Haliph);
2607, 2533 (B–H); 1767 (C=O); 1626 (C=N); 1604,
1506, 1463, 1418 (C=Carom); 1248, 1196, 1152, 1120,
1096, 1032 (C–O); 860, 840, 790, 780, 750, 731, 719,
1
690 (δC–Harom, δC–Hcarb). H NMR spectrum, δ, ppm:
3.03 br.s (1H, 7-H), 3.88 s (3H, MeO), 4.07 br.s (1H,
2′-H), 6.80–7.50 m (8H, Harom, NH), 8.48 s (1H,
CH=N). Found, %: C 41.67; H 6.10; B 36.95; N 4.38.
C20H34B20N2O4. Calculated, %: C 41.22; H 5.88;
B 37.11; N 4.81.
1
870, 840, 820, 775, 754, 742 (δC–Harom). H NMR
spectrum, δ, ppm: 2.24 s (3H, Me), 3.30–4.10 m (4H,
CH2), 3.89 s (3H, MeO); 4.98 s, 5.50 m, and 5.80 m
(3H, CH, pyrrole), 6.80–7.15 m (3H, Harom), 7.37 s
(1H, CH=N). Found, %: C 52.41; H 4.10; Cl 15.70;
N 9.22; S 7.01. M 419.4. C19H17Cl2N3O3S. Calculated,
%: C 52.07; H 3.91; Cl 16.18; N 9.59; S 7.30. M 438.2.
4-[(E)-{3-[1,2-Dicarba-closo-dodecaborane(12)-
1-carbonylamino]phenylimino}methyl]-2-ethoxy-
phenyl 1,7-dicarba-closo-dodecaborane(12)-1-car-
boxylate (VIh). Yield 77%, mp 224–225°C (from
MeOH). IR spectrum, ν, cm–1: 3090, 3065, 3004
(C–Harom, C–Hcarb); 2980, 2926, 2900, 2876, 2855
(C–Haliph); 2608, 2535 (B–H); 1766 (C=O); 1626
(C=N); 1604, 1505, 1464, 1420 (C=Carom); 1249, 1193,
1120, 1096, 1058, 1033 (C–O); 862, 840, 792, 780,
N-(3-Aminophenyl)-1,2-dicarba-closo-dodeca-
borane(12)-1-carboxamide (V). A solution of 5 mmol
of 1,2-dicarba-closo-dodecaborane(12)-1-carbonyl
chloride in 10 ml of anhydrous tetrahydrofuran was
added over a period of 30 min to a solution of 15 mmol
of benzene-1,2-diamine and 10 mmol of pyridine in
20 ml of THF under vigorous stirring at 20–23°C in
an argon atmosphere. The mixture was stirred for 6 h,
1
750, 731, 690 (δC–Harom, δC–Hcarb). H NMR spec-
trum, δ, ppm: 1.40 t (3H, Me), 3.03 br.s (1H, 7-H),
4.07 br.s (1H, 2′-H), 4.08 q (2H, OCH2), 6.85–7.50 m
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 1 2010

FUNCTIONALLY SUBSTITUTED AROMATIC SCHIFF BASES
63
5. Rosenthal, M.A., Kavar, B., and Hill, J.S., J. Clin.
Oncol., 2001, vol. 19, p. 519.
6. Evstigneeva, R.P., Zaitsev, A.V., Luzgina, V.N., Ol’shev-
skaya, V.A., and Shtil, A.A., Curr. Med. Chem.–Anti
Cancer Agents, 2003, vol. 3, no. 6, p. 383.
and the precipitate of compound V and pyridine hydro-
chloride was filtered off, washed with THF (2×5 ml)
and methanol (3×5 ml) to remove pyridine hydro-
chloride, and dried for 24 h in a vacuum desiccator
over silica gel. Yield 94%, mp 69–70°C (from THF).
IR spectrum, ν, cm–1: 3363 (N–H); 3110, 3085, 3040,
3015 (C–Harom, C–Hcarb.); 2960, 2925, 2875, 2855,
2830 (C–Haliph); 2517, 2420 (B–H); 1660 (C=O); 1621,
1604, 1525, 1488, 1458, 1437, 1412 (C=Carom); 749,
7. Syaopin Zhao, Dzen Kvang Song, Radbil’, A.B., and
Radbil’, B.A., Zh. Prikl. Khim., 2007, vol. 80, p. 1334.
8. Minbaev, B.U., Shiffovy osnovaniya (Schiff Bases),
Alma-Ata: Nauka Kaz. SSR, 1989, p. 140.
1
9. Dyer, J.R., Applications of Absorption Spectroscopy of
Organic Compounds, Englewood Cliffs: Prentice–Hall,
1965. Translated under the title Prilozheniya absorb-
tsionnoi spektroskopii organicheskikh soedinenii,
Moscow: Khimiya, 1970, p. 92.
687 (δC–Harom). H NMR spectrum, δ, ppm: 4.08 br.s
(1H, 2-H), 7.58–8.96 m (7H, Harom, NH2, NH). Found,
%: C 39.16; H 6.71; B 38.25; N 9.78. C9H18B10N2O.
Calculated, %: C 38.83; H 6.52; B 38.84; N 10.06.
10. Dikusar, E.A., Vyglazov, O.G., Moiseichuk, K.L.,
Zhukovskaya, N.A., and Kozlov, N.G., Zh. Prikl. Khim.,
2005, vol. 78, p. 122.
REFERENCES
1. Soloway, A.H., Tjarks, W., Barnum, B.A., Rong, F.-G.,
Barth, R.F., Codogni, I.M., and Wilson, J.G., Chem. Rev.,
1998, vol. 98, p. 1515.
11. Dikusar, E.A. and Kozlov, N.G., Khim. Prirodn. Soedin.,
2005, p. 74.
12. Dikusar, E.A. and Kozlov, N.G., Russ. J. Org. Chem.,
2. Hawtorne, M.F. and Maderna, A., Chem. Rev., 1999,
2005, vol. 41, p. 992.
vol. 99, p. 3421.
13. Dikusar, E.A., Zh. Prikl. Khim., 2006, vol. 79, p. 1043.
3. Belykh, D.V. and Kuchin, A.V., Materialy III Mezhduna-
rodnoi konferentsii “Khimiya, struktura i funktsiya bio-
molekul” (Proc IIIrd Int. Conf. “Chemistry, Structure, and
Function of Biomolecules”), Minsk: Pravo i Ekonomika,
2008, p. 41.
14. Dikusar, E.A., Potkin, V.I., Kozlov, N.G., Yuvchen-
ko, A.P., Bei, M.P., and Kovganko, N.V., Russ. J. Org.
Chem., 2008, vol. 44, p. 1305.
15. Nadzhafova, R.A., Russ. J. Org. Chem., 2002, vol. 38,
p. 858.
4. Mal’shakova, M.V., Belykh, D.V., Ol’shevskaya, V.A.,
Kalinin, V.N., and Kuchin, A.V., Materialy III Mezhduna-
rodnoi konferentsii “Khimiya, struktura i funktsiya bio-
molekul” (Proc IIIrd Int. Conf. “Chemistry, Structure, and
Function of Biomolecules”), Minsk: Pravo i Ekonomika,
2008, p. 160.
16. Nechai, N.I., Dikusar, E.A., Potkin, V.I., and Kaber-
din, R.V., Russ. J. Org. Chem., 2004, vol. 40, p. 1009.
17. Grimes, R., Carboranes, New York: Academic, 1970.
Translated under the title Karborany, Moacow: Mir,
1974, p. 264.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 1 2010