I. Huc et al.
were dissolved in anhydrous THF (20 mL) and cooled to 08C. Isobutyl
alcohol (700 mL) and then diisopropylazadicarboxylate (1.4 mL,
7.3 mmol) were added dropwise at 08C. The reaction mixture was stirred
for 1 h at 08C and then 12 h at 258C. It was then evaporated to dryness
and the residue was purified by chromatography on silica eluting with
toluene/ethyl acetate from 97:3 to 90:10 vol/vol; to obtain 5 (1.6 g, 90%
dry N,N-diisopropylethylamine (0.066 mL, 0.37 mmol) in anhydrous THF
(2 mL) was added to freshly prepared 7 (32 mg, 0.007 mmol) suspended
in THF (1 mL) at 08C. The reaction was stirred for 30 min at 08C then
12 h at 258C. The solvent was removed by evaporation and the residue
was purified by flash chromatography on silica gel eluting with EtOAc/
CH2Cl2 8:92 vol/vol. Compound 3 (75 mg, 71%) was obtained as a
yellow powder. 1H NMR (300 MHz, CDCl3): d=10.22 (s, 2H), 9.18–9.00
(brs, 4H), 8.41 (s, 1H), 7.99 (d, J(H,H) =7.7 Hz, 2H), 7.83 (m, 4H), 7.72 (t,
1
yield). H NMR (300 MHz, CDCl3): d=9.14 (s, 1H), 7.50 (s, 2H), 4.13 (d,
J
(H,H) =6.4 Hz, 4H), 4.10 (s, 6H), 3.50 (s,3H), 2.36 (sept, J(H,H) =6.8 Hz,
2H), 1.20 ppm (d, J(H,H) =6.6 Hz, 12H); 13C NMR (75 MHz, CDCl3): d=
J
(H,H) =6.7 Hz, 2H), 7.44 (m, 14H), 6.89, (m, 4H), 5.3 (s, 2H), 4.14 (m,
4H), 3.55 (s, 3H), 2.34 (m, 4H), 1.22 (m, 20H), 0.54 ppm (s, 16H);
166.3, 163.2, 149.6, 145.7, 139.0, 121.4, 113.3, 98.6, 74.9, 53.1, 28.2, 19.1,
HRMS(ESI): m/z: calcd for C81H80N16O14Na: 1523.5938; found:
C
13.0 ppm; HRMS(ESI): m/z: calcd for C25H29N2O6: 455.2195; found:
C
X-ray crystallography: Single crystals of heptamer 2 were mounted on a
Rigaku R-Axis Rapid diffractometer equipped with a MM007 micro-
focus rotating anode generator (monochromatized Cuka radiation,
1.54178 ). The data collection, unit cell refinement, and data reduction
were performed by using the CrystalClearTM software package. The posi-
tions of non-H atoms were determined by the program SHELXD, and
the position of the H atoms were deduced from coordinates of the non-H
atoms and confirmed by Fourier synthesis. H atoms were included for
structure factor calculations but not refined.
1,8-Diaza-4,5-diisobutoxy-9-methyl-2,7-anthracenedicarbonyl
chloride
(7):[15] Under an anhydrous atmosphere and protection from light, 5 (1 g,
2.2 mmol) was dissolved in 1,4-dioxane/water (50 mL, 8:2 vol/vol).
Sodium hydroxide (220 mg, 5.5 mmol) was added and the reaction was
stirred at 258C for 12 h. Acetic acid was added until the pH dropped
below 7. The dioxane was evaporated and the aqueous solution was ex-
tracted with chloroform. The organic phase was dried (MgSO4), filtered,
and evaporated by using a toluene azeotrope to yield 6 (930 mg, quanti-
tative), which was used without further purification. 1H NMR (300 MHz,
CDCl3): d=9.71 (s, 1H), 8.09 (s, 2H), 4.64 (d, J(H,H) =6.4 Hz, 4H), 3.35 (s,
3H), 2.52 (sept, J(H,H) =6.8 Hz, 2H), 1.20 ppm (d, J(H,H) =6.6 Hz, 12H).
CCDC-644896 (2·toluene/hexane), CCDC-644894 (2·DMSO), and
CCDC-644895 (2·MeOH) contain the supplementary crystallographic
data for this paper. These data can be obtained free of charge from The
request/cif.
NMR studies: The 400 MHz 1H NMR spectra were recorded by using a
Bruker–Avance 400 NB US NMR spectrometer by means of a 5 mm
direct QNP 1H/X probe with gradient capabilities. The solvent signal was
used as an internal reference for these spectra. Samples were not de-
gassed. Rotating frame nuclear Overhauser spectroscopy (ROESY) was
used with the following acquisition parameters: 908 pulse-width and
Diacid 6 (150 mg) was then suspended in anhydrous CHCl3 (12 mL). 1-
Chloro-N,N, 2-trimethylpropenylamine (0.12 mL, 0.870, 2.5 equiv) was
added and the reaction was stirred at 258C for 3 h. The reaction mixture
remains a suspension the reaction does reach completion under those
conditions. The solvent and the excess reagents were evaporated and the
residue was dried in a vacuum line for at least 2 h to yield 7 as a yellow-
orange solid. 1H NMR (300 MHz, CDCl3): d=9.12 (s, 1H), 7.39 (s, 2H),
3.53 (s, 3H), 2.38 (m, 2H), 1.21 ppm (d, J(H,H) =6.6 Hz, 12H).
Trimeric oligomer 9: Under an anhydrous atmosphere and protection
from light, a solution of 2-amino-6-tert-butoxycarbonylaminopyridine[16]
transmitter attenuation for the spin-lockpulses were calibrated, P1
=
13 ms, PL1=0 dB, spin-lockfield strength =4807 Hz; 1024(t2).512(t1)
data points in States-TPPI mode with Z gradients selection and with
CW-spin lockfor mixing; relaxation delay of 2 s and 40 scans per incre-
ment; sweep width of 5200 Hz in both dimensions; mixing time of
250 ms. Processing was done after a sine-bell multiplication in both di-
mensions, and Fourier transformed in 1 K.1 K real data points. Data
processing was performed by using the XWIN-NMR software.
(430 mg,
2.08 mmol)
and
N,N-diisopropylethylamine
(0.16 mL,
2.08 mmol) in anhydrous CH2Cl2 (3 mL) was added to freshly prepared 7
(32 mg, 0.7 mmol) suspended in anhydrous CH2Cl2 (10 mL) at 08C. The
reaction was stirred at 08C for 30 min and then at 258C for 12 h. The
mixture was evaporated to dryness and the product was purified by chro-
matography on SiO2 eluting with MeOH/CH2Cl2 1:99 vol/vol to yield 9
(0.3 g, 53%) as a yellow powder. 1H NMR (300 MHz, CDCl3): d=10.66
(s, 2H), 9.14 (s, 1H), 8.1 (d, J(H,H) =7.5 Hz, 2H), 7.76 (m, 6H), 7.17 (s,
2H), 4.18 (d, J(H,H) =6.4 Hz, 4H), 3.52 (s, 3H), 2.38 (sept, J(H,H) =6.8 Hz,
Fluorescence studies: Fluorescence spectra were collected by means of a
Shimadzu F4500 spectrofluorometer using a thermostatted cuvette holder
(lex =416 nm) and are uncorrected. The binding isotherms were deter-
mined in an aerated pyridine solution at 208C by monitoring the fluores-
cence emission intensity at l=484 and 469 nm as a function of increasing
concentration of 2 (from 5.510-7 m to 2.310-5 m). To avoid complica-
tions from variations in the fluorescence emission envelope owing to
changes in the absorption spectrum, ratiometric analysis using least-
squares fitting of the data was performed according to Equation (2).
2H), 1.55 (s, 18H), 1.21 ppm (d,
(75 MHz, CDCl3): d=164.3, 162.9, 152.3, 151.4, 150.7, 149.4, 144.9, 140.8,
121.6, 119.8, 114.2, 114.3, 108.2, 96.45, 81.2, 75.5, 28.4, 19.3 ppm. MS-
J
(H,H) =6.6 Hz, 12H); 13C NMR
G
[3M+2Na]2+, 1618.1 [2M+H]+, 1639.1 [2M+H+Na]+.
Heptameric oligomer 2: Under an anhydrous atmosphere and protection
from light, a solution of boc-monoprotected pyridine trimer 8[16] (202 mg,
0.45 mmol) and distilled N,N-diisopropylethylamine (0.2 mL, 1.1 mmol)
in anhydrous THF (6 mL) was added to freshly prepared diacid chloride
7 (98 mg, 0.212 mmol) suspended in anhydrous THF (3 mL) at 08C. The
reaction was stirred for 30 min at 08C and then 12 h at 258C. The solvent
was removed by evaporation and the residue was purified by means of
flash chromatography on silica gel eluting with EtOAc/cycloexane 35:65
to 50:50 vol/vol. Compound 2 (186 mg, 66%) was obtained as a yellow
powder. 1H NMR (300 MHz, CDCl3): d=10.26 (s, 2H), 9.13–9.01 (brs,
4H), 8.22 (brd, 2H), 8.13 (s, 1H), 8.04 (d, J(H,H) =7.2 Hz, 2H), 7.90–7.85
(m, 4H), 7.76–7.68 (m, 4H), 7.3 (s, 2H), 7.02–6.9 (m, 4H), 6.75 (brd,
2H), 4.24 (dd, J(H,H) =8.4, 6.3 Hz, 2H), 4.12 (dd, J(H,H) =8.4, 6.3 Hz, 2H),
3.64 (s, 3H), 2.51 (sept, J(H,H) =6.8 Hz, 2H), 1.39 (dd, J(H,H) =6.6, 4.5 Hz,
12H), 0.561 ppm (s, 18H); 13C NMR (75 MHz, CDCl3): d=163.8, 161.4,
160.7, 159.7, 152.8, 151.2,150.8, 149.0, 148.9, 148.5, 148.3, 147.5, 143.8,
140.6, 140.0, 138.2, 136.1, 125.7, 125.5, 120.5, 114.2, 110.2, 109.5, 109.4,
RF ÀlM
ð2Þ
½Dꢁ ¼ C
0 lDÀ2lM
The value [D] is the concentration of 2 present in the form of a dimer, C0
is the total concentration of 2, RF is the ratio of fluorescence emission in-
tensity at l=484 and 469 nm, and lM and lD are the ratio of the products
of the molar extinction coefficient and the fluorescence quantum yield
(f) at l=484 and 469 nm for the monomer and dimer of 2, respectively
[Eq. (3)]:
484
D,M D,M
469
D,M D,M
e
e
ꢀ484
ꢀ469
lD,M
¼
ð3Þ
The temperature dependence of Kdim was obtained in aerated pyridine
solution at [2]=1.410-4 m by evaluating Kdim from the relative emission
intensity at l=484 and 469 nm using the values of lD and lM previously
obtained from analysis of the binding isotherm. The data was analyzed
according to the vanꢀt Hoff equation : lnK=ÀDH/RT+DS/R.
108.13, 96.2, 75.3, 28.6, 27.3, 19.5, 19.4, 14.2, 13.0 ppm; HRMS(ESI): m/z:
A
calcd for C67H69N16NaO12: 1289.5281; found: 1289.5205 [M+Na]+.
Heptameric oligomer 3: Under an anhydrous atmosphere and protection
from light, a solution of trimeric oligomer 8b (85 mg, 0.152 mmol) and
8468
ꢁ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2007, 13, 8463 – 8469