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S. Follot et al. / European Journal of Medicinal Chemistry 44 (2009) 3509–3518
interactions leading to a more rigid structure and soluble
spheric aggregates;
- Enhancement of membrane interactions/penetration could be
achieved by hydroxyl substitutions (1 and/or 2 groups) on the
C6 lateral chain.
a mixture of 1 mL of NH4OH 30% and 20 mL of water, and then
extracted with DCM. The organic layer was dried over anhydrous
MgSO4 and concentrated to dryness. The residue was chromato-
graphed on alumina eluted with DCM and then a mixture of DCM–
methanol (98–2).
These propositions are currently tested in current syntheses.
6. Experimental section
6.1.2.1. 2-[2-(4-Fluorophenyl)-3-pyridin-4-ylimidazo[1,2-a]pyridin-
6-ylamino]ethanol (3a). M ¼ 120 mg. Yield: 34.5%. Mp ¼ 205 ꢁC
(dec). 1H NMR (400.13 MHz, CDCl3): 8.76 (d, J ¼ 5.8 Hz, 2H, Pyr-
´
3,5), 7.55 (d, J ¼ 9.5 Hz, 1H, H-8), 7.53 (dd, J ¼ 8.5–5.4 Hz, 2H, F-Ph-
2,6), 7.39 (d, J ¼ 5.8 Hz, 2H, Pyr-3,5), 7.32 (d, J ¼ 1.4 Hz, 1H, H-5),
7.00 (t, J ¼ 8.5 Hz, 2H, F-Ph-3,5), 6.89 (d, J ¼ 9.5 Hz, 1H, H-7),
3.90 (t, J ¼ 5.1 Hz, 2H, CH2), 3.15 (t, J ¼ 5.1 Hz, 2H, CH2). 13C
NMR (100 MHz, CDCl3): 162.5 (J ¼ 255.6 Hz, C–F), 151.1 (C–H),
140.9 (C), 138.2 (C), 137.4 (C), 130.0 (J ¼ 8 Hz, C–H), 129.6 (C), 129.1
(C), 127.2 (C), 124.5 (C–H), 121.0 (C–H), 118.1 (C–H), 115.5
(J ¼ 21.1 Hz, C–H), 102.7 (C–H), 60.9 (CH2), 46.5 (CH2). Mass
spectroscopy: m/z ¼ 348. The spectra were acquired in MeOH as
solvent with 10% DMSO.
6.1. Chemistry
The melting points were determined in
a
capillary
apparatus and are uncorrected. The NMR spectra were recorded
on spectrometer Bruker AM 400 WB or AVANCE-DMX-400
instruments and chemical shifts are expressed in ppm relative to
trimethyl silyl propionic acid sodium (TSP) from residual CHCl3 at
d
7.3 (1H) and central resonance of CDCl3 at 77.1 (13C). The NMR
d
spectra of compound 1 were performed at 200 MHz (1H) and
50 MHz (13C) in CDCl3 or DMSO-d6 on Bruker DPX 200 instru-
ments. Signals are described as singlet (s), broad singlet (bs),
doublet (d), triplet (t), quartet (q) and multiplet (m). Possible
inversion of two values in the NMR spectra is expressed by an
asterisk. Elemental analyses (C, H, N) were within ꢄ 0.4% of
6.1.2.2. 4-[2-(4-Fluorophenyl)-3-pyridin-4-ylimidazo[1,2-a]pyridin-
6-ylamino]butan-1-ol (3b). M ¼ 186 mg. Yield: 49%. Mp ¼ 200 ꢁC.
1H NMR (400.13 MHz, CDCl3): 8.76 (d, J ¼ 5.8 Hz, 2H, Pyr-2, 6), 7.54
(d, J ¼ 9.8 Hz, 1H, H-8), 7.53 (dd, J ¼ 8.8–5.4 Hz, 2H, F-Ph-2,6), 7.39
(d, J ¼ 5.8 Hz, 2H, Pyr-3,5), 7.24 (d, J ¼ 1.7 Hz, 1H, H-5), 7.00 (t,
J ¼ 8.8 Hz, 2H, F-Ph-3,5), 6.85 (dd, J ¼ 9.5–2 Hz, 1H, H-7), 3.71 (t,
J ¼ 6 Hz, 2H, CH2), 3.00 (t, J ¼ 6.5 Hz, 2H, CH2), 1.73 (m, 4H, 2CH2).
13C NMR (100 MHz, CDCl3): 162.5 (J ¼ 252 Hz, C–F), 151.1 (CH), 142.1
(C), 138.5 (C), 137.3 (C), 130.0 (J ¼ 7.7 Hz, C–H), 129.6 (C), 129.1 (C),
127.4 (C), 124.5 (C–H), 121.2 (C–H), 117.8 (C–H), 115.6 (J ¼ 21.8 Hz, C–
H), 101.9 (C–H), 62.4 (CH2), 44.3 (CH2), 30.2 (CH2), 25.7 (CH2). Mass
spectroscopy: m/z ¼ 377. The spectra were acquired in MeOH as
solvent with 10% DMSO.
theory. 2-(4-Fluorophenyl)-6-iodoimidazo[1,2-a]pyridine
prepared by a multistep synthesis previously reported in the
literature [44].
1 was
6.1.1. 2-(4-Fluorophenyl)-6-iodo-3-pyridin-4-ylimidazo
[1,2-a]pyridine (2)
To a solution of 6-iodo-2-(4-fluorophenyl)imidazo[1,2-a]pyri-
dine 1 (3 g, 8.9 mmol) in 7.6 mL of pyridine (7 g, 88.8 mmol) were
added dropwise 4.8 mL of ethyl chloroformate (4.8 g, 44.4 mmol)
at a temperature comprised between 0 and 5 ꢁC. After 3 h of
stirring at room temperature, the same volumes of pyridine and
ethyl chloroformate were again added to the cooled reaction
mixture. After 2 h of stirring, the suspension was treated with
100 mL of water and extracted with 100 mL of DCM. The organic
layer was washed three times with water and dried over anhy-
drous MgSO4. After concentration, the residue was dissolved in
20 mL of toluene, added of o-chloranil (2.2 g, 8.9 mmol) and
stirred at room temperature for 3 h. The reaction mixture was
then neutralised with an aqueous solution of NaOH 2 N and
extracted with DCM. The organic layer was dried over anhydrous
MgSO4 and concentrated to dryness. The residue was chromato-
graphed on silica gel eluted with DCM–methanol (99–1) (1.75 g).
Yield: 47.5%. Mp ¼ 240 ꢁC. 1H NMR (200.13 MHz, CDCl3): 8.85 (d,
J ¼ 5.8 Hz, 1H, Pyr-2, 6), 8.32 (m, 1H, H-5), 7.59 (dd, J ¼ 9–5.4 Hz,
2H, F-Ph-2,6), 7.56 (d, J ¼ 9.6 Hz, 1H, H-8), 7.54 (dd, J ¼ 9.6–1.4 Hz,
1H, H-7), 7.42 (d, J ¼ 5.8 Hz, 2H, Pyr-3,5), 7.06 (t, J ¼ 9 Hz, 2H, F-
Ph-3,5). 13C NMR (50 MHz, CDCl3): 163.2 (J ¼ 247 Hz, C–F), 151.7
(C–H), 144.5 (C), 143.9 (C), 137.7 (C), 134.0 (C–H), 130.57 (J ¼ 8 Hz,
C–H), 129.4 (C), 128.22 (C–H), 124.91 (C–H), 119.3 (C–H), 118.31 (C),
116.0 (J ¼ 21.5 Hz, C–H), 76.5 (C–I).
6.1.2.3. 6-[2-(4-Fluorophenyl)-3-pyridin-4-ylimidazo[1,2-a]pyridin-
6-ylamino]hexan-1-ol (3c). M ¼ 126 mg. Yield: 31.2%. Mp ¼ 200 ꢁC.
1H NMR (400.13 MHz, CDCl3): 8.76 (d, J ¼ 6 Hz, 2H, Pyr-2, 6), 7.54
(m, 3H, H-8, F-Ph-2,6), 7.39 (d, J ¼ 6 Hz, 2H, Pyr-3,5), 7.22 (d,
J ¼ 1.7 Hz, H-5), 7.00 (t, J ¼ 8.7 Hz, 2H, F-Ph-3,5), 6.84 (dd, J ¼ 9.6–
2 Hz, 1H, H-7), 3.67 (t, J ¼ 6.5 Hz, 2H, CH2), 3.42 (bs, 1H, NH), 2.96
(m, 2H, CH2), 1.67 (m, 2H, CH2), 1.60 (m, 2H, CH2), 1.44 (m, 4H,
2CH2). 13C NMR (100 MHz, CDCl3): 162.5 (J ¼ 246 Hz, C–F), 151.1
(C–H), 142.0 (C), 138.5 (C), 137.4 (C), 130.0 (J ¼ 8 Hz, C–H), 124.6
(C–H), 121.0 (C–H), 120.6 (C), 118.2 (C), 117.8 (C–H), 115.5
(J ¼ 21 Hz, C–H), 106.3 (C), 101.8 (C–H), 62.9 (CH2), 44.4 (CH2),
32.7 (CH2), 29.2 (CH2), 27.0 (CH2), 25.7 (CH2). Mass spectroscopy:
m/z ¼ 404. The spectra were acquired in MeOH as solvent with
10% DMSO.
6.2. Cell culture
The human myelomonocytic cell line, THP-1 (ECACC 88081201;
Sophia-Antipolis, France) [45–47] was used. These non-adherent
cells were grown in suspension in RPMI 1640 with glutamaxÔ-I
(Gibco, Eragny, France) and antibiotics (100 U/mL penicillin,100 mg/
6.1.2. General procedure for the Buchwald reaction coupling
2-(4-Fluorophenyl)-6-iodo-3-pyridin-4-ylimidazo[1,2-a]pyridine
(415 mg, 1 mmol), copper (I) iodide (9.5 mg, 0.05 mmol), and
potassium phosphate (425 mg, 2 mmol) were added to a screw-
capped test tube. The tube was evacuated and back filled with
mL streptomycin) (Gibco), supplemented with 10%(v/v) heat-inac-
tivated fetal calf serum (Gibco). The THP-1 cells were incubated at
37 ꢁC under a 5% CO2/95% air atmosphere (v/v).
argon (three times). Ethylene glycol (111
mL, 2 mmol), amine
6.3. Vesicule preparation
(1.2 mmol) and butanol (1 mL) were added successively by syringe
at room temperature. The tube was sealed with a Teflon-lined cap
and the reaction mixture was heated at 100 ꢁC for 14 h. After
cooling to room temperature, the suspension was diluted with
L
-
a
-Phosphatidylcholine from egg yolk (EPC) and synthetic
dimyristoyl phosphatidylcholine (DMPC) were obtained from
Sigma, la Verpillere, France. DMPC deuterated on both chains or
`