H, m, CH2CH2(CH2)12CH3), 1.63 (2 H, m, CH2CH2(CH2)12CH3),
2.26 (2 H, m, CH2CH2(CH2)12CH3), 3.48 (2 H, s, CH2COOH),
4.12 (2 H, bd, J = 6.4 Hz, CH2NHCO), 5.80–6.50 (1 H, bs,
COOH), 6.49 (1 H, bs, CH2NHCO); dC (50.2 MHz; CDCl3,
Me4Si) 13.9 (1 ¥ q), 22.5 (1 ¥ t), 25.3 (1 ¥ t), 29.0 (1 ¥ t), 29.1 (1 ¥
t), 29.2 (1 ¥ t), 29.3 (3 ¥ t), 29.5 (3 ¥ t), 31.7 (1 ¥ t), 36.1 (1 ¥ t),
40.6 (1 ¥ t), 41.4 (1 ¥ t), 41.7 (1 ¥ t), 74.1 (1 ¥ s), 79.0 (1 ¥ s), 170.0
(1 ¥ s), 173.9 (1 ¥ s); m/z (ESI+) 493 [M + Na]+.
and the solvent evaporated. Inorganic salts were removed by gel
R
filtration on Sephadexꢀ G10 column using a 50:50 mixture of
water and MeOH as eluent. The solvent was removed affording
80 mg of complex 15 (0.07 mmol, 64%). Found C, 46.61; H, 7.65;
N, 8.83%. Calc. for C43H84B10GdN7O9: C, 46.59; H, 7.64; N, 8.84%.
nmax (neat)/cm-1 3447, 2926, 2589, 1683, 1626, m/z (ESI+) 1131
[M + Na]+.
C-(tert-ButylDOTAMA-C6 -amidomethyl)-C¢-palmitamidome-
thyl-o-carborane (13). Method for the preparation of 10 was
used, derivative 12 (0.527 mmol, 0.255 g), CMDT (0.517 mmol,
0.91 g) and N-methylmorpholine (0.527 mmol, 60 mL) were
dissolved in 5 mL of in anhydrous CH2Cl2 at 0 ◦C. After
4 h N-tert-ButDOTAMA-C6-NH2 (0.517 mmol, 0.347 g), N-
methylmorpholine (0.517 mmol, 57 mL) in 10 mL of anhydrous
CH2Cl2 were added. The solution was stirred for 60 h, then treated
as described above. A pale yellow solid was obtained and purified
by chromatography (CH2Cl2-MeOH 96–4, then CH2Cl2-MeOH
80–20) affording 237 mg of a viscous colorless oil (40%). Found
C, 59.00; H, 9.94; N, 8.75% Calc. for C55H111B10N7O9: C, 58.84;
H, 9.97; N, 8.76%. nmax (neat)/cm-1 3437, 2581, 1732, 1670. dH
(200 MHz; CDCl3, Me4Si) 0.86 (3 H, m, CH3), 1.23 (24 H,
m, CH2CH2(CH2)12CH3), 1.44 (27 H, s, COOtBu), 1.00–2.00
(12 H, m, CH2CH2(CH2)12CH3, CH2CH2NH), 2.00–3.00 (22 H,
m, CH2NCOOtBu, CH2CONH, CH2NH), 3.00–4.20 (10 H, m,
CH2COOtBu), 8.10 (1 H, bs, J = 6.4 Hz, NHCH2CO), 8.80 (2 H,
bs, CH2NHCO); dC (50.2 MHz; CDCl3, Me4Si) 13.9 (1 ¥ q), 25.1
(1 ¥ t), 25.3 (2 ¥ t), 25.5 (2 ¥ t), 27.3 (9 ¥ q), 28.2 (2 ¥ t), 28.4 (2 ¥
t), 29.1 (3 ¥ t), 29.3 (2 ¥ t), 29.5 (2 ¥ t), 31.7 (1 ¥ t), 36.0 (1 ¥ t),
38.0 (1 ¥ t), 38.4 (1 ¥ t), 41.1 (1 ¥ t), 41.4 (1 ¥ t), 48.0–56.0 (8 ¥ t),
55.3 (2 ¥ t), 55.5 (1 ¥ t), 55.9 (1 ¥ t), 75.8 (1 ¥ s), 80.8 (1 ¥ s), 81.6
(2 ¥ s), 81.7 (1 ¥ s), 166.3 (1 ¥ s), 171.0 (1 ¥ s), 171.9 (1 ¥ s), 172.2
(2 ¥ s), 173.6 (1 ¥ s); m/z (ESI+) 1124 [M + H]+.
Notes and references
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yl-o-carborane complex (14). In a 50 mL round bottom flask,
140 mg (0.12 mmol) of product 13 were cooled to 0 ◦C, dissolved in
5 mL of a mixture of CF3COOH-CH2Cl2 (50–50) and stirred for 4 h
at rt. After evaporation of CF3COOH-CH2Cl2 115 mg of viscous
colorless oil were obtained (99%). Found C, 54.28; H, 9.16; N,
10.24%. Calc. for C43H87B10N7O9:C, 54.12;H, 9.19; N, 10.27%. nmax
(neat)/cm-1 3323, 2922, 2585, 1682. dH (200 MHz; MeOD, Me4Si)
0.87 (3 H, m, CH3), 1.29 (24 H, m, CH2CH2(CH2)12CH3), 1.00–
2.00 (14 H, m, CH2CH2(CH2)12CH3, CH2CH2NH, CH2CH2CO),
2.25 (2 H, bt, J = 6.8 Hz (CH2)12CH2CO), 3.00–4.30 (28 H, m,
CH2NCOOH, CH2CONH, CH2NH), 7.20 (3 H, bs, NHCH2CO,
CH2NHCO); dC (50.2 MHz; CDCl3, Me4Si) 12.9 (1 ¥ q), 22.1 (1 ¥
t), 25.2 (1 ¥ t), 25.6 (1 ¥ t), 28.4 (1 ¥ t), 28.7 (2 ¥ t), 28.8 (3 ¥
t), 28.9 (5 ¥ t), 29.2 (3 ¥ t), 31.4 (2 ¥ t), 35.1 (1 ¥ t), 38.9 (1 ¥ t),
41.3 (1 ¥ t), 52.5 (2 ¥ t), 52.6 (1 ¥ t), 53.9 (1 ¥ t), 76.1 (1 ¥ s),
80.1 (1 ¥ s), 159.8 (1 ¥ s), 160.5 (1 ¥ s), 166.8 (1 ¥ s), 174.5 (3 ¥
s);26 m/z (ESI+) 956 [M + H]+. In a 10 mL round bottom flask,
110 mg of deprotected intermediate (0.11 mmol) and 1 equivalent
of GdCl3 were dissolved in a 50:50 mixture of water and MeOH
at rt. The pH solution was checked and maintained to 6.5 by 1 M
NaOH aqueous solution. The solution was stirred overnight, then
the pH was adjusted to 8.5 by 1 M NaOH aqueous solution and
the mixture was stirred for 2 h, then filtered over 0.2 mm syringe
filter, the pH was adjusted to 7 by a 1 M HCl aqueous solution
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This journal is
The Royal Society of Chemistry 2008
Org. Biomol. Chem., 2008, 6, 4460–4466 | 4465
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