Journal of Medicinal Chemistry
Article
0.5 M NaOMe/MeOH (14 μL) until completion of the reaction. The
reaction mixture was neutralized with amberlyst-15 (H+) ion-exchange
resin and filtered. The filtrate was concentrated, and the residue was
purified by chromatography on silica (DCM/MeOH, 10:1) and P2 size
exclusion chromatography to afford 21 (20 mg, 70%) as a white solid
Overall, these results clearly indicate the high therapeutic
potential of this new series of FimH antagonists. Because of
optimized PK properties, a substantial reduction of the dosage
could be achieved. Thus, with the most promising representative
to date, the indolinylphenyl α-D-mannoside 48a, the infection
can be successfully treated with a low dosage of 1 mg/kg
(approximately 25 μg/mouse) without any additional admin-
istration of antibiotics.
20
after a final lyophilization from water/dioxane. [α]D +171.6 (c 0.18,
MeOH). 1H NMR (500 MHz, CD3OD): δ 7.62−7.54 (m, 3H, Ar−H),
7.45−7.38 (m, 3H, Ar−H), 7.18 (t, J = 7.0 Hz, 1H, Ar−H), 7.11 (t, J =
7.0 Hz, 1H, Ar−H), 6.65 (s, 1H, Ar−H), 5.61 (s, 1H, H-1), 4.14 (m,
1H, H-2), 4.01 (dd, J = 9.0, 2.5 Hz, 1H, H-3), 3.81−3.69 (m, 4H, H-6a,
H-4, H-6b, H-5). 13C NMR (125 MHz, CD3OD): δ 151.81, 137.30,
136.22, 130.81, 128.98, 127.04, 125.58, 124.98, 123.49, 122.06, 121.42,
119.23, 111.00, 104.71 (Ar−C), 101.03 (C-1), 76.11 (C-5), 72.38 (C-3),
71.84 (C-2), 68.22 (C-4), 62.70 (C-6). HRMS (ESI) m/z calcd for
C20H20ClNNaO6 [M + Na]+, 428.0877; found, 428.0875.
EXPERIMENTAL SECTION
■
Synthesis. The synthesis of compounds 7−10, 14−20, 23−37,
39−42, 44, 47b,d, 48b,d, 50−52, and 55−58, including compound
characterization data, can be found in the Supporting Information.
General Methods. Commercially available reagents were purchased
from Fluka, Aldrich, Merck, AKSci, ASDI, or Alfa Aesar. Methanol
(MeOH) was dried by distillation from sodium methoxide. Toluene
and dioxane were dried by distillation from sodium/benzophenone.
Optical rotations were measured at 20 °C on a Perkin-Elmer 341
polarimeter. Nuclear magnetic resonance (NMR) spectra were
obtained on a Bruker Avance 500 UltraShield spectrometer at
500.13 MHz (1H) or 125.76 MHz (13C). Chemical shifts are given
in ppm and were calibrated on residual solvent peaks or to
tetramethylsilane as an internal standard. Multiplicities are specified
as s (singlet), d (doublet), dd (doublet of a doublet), t (triplet),
2-Chloro-4-(5-nitroindol-1-yl)phenyl α-D-Mannopyranoside (22).
According to the procedure described for 21, compound 22 was
prepared from 7 (117 mg, 0.20 mmol) and 5-nitroindole (11f, 39 mg,
0.24 mmol) via the acetylated intermediate 13. After workup, the
residue was purified by chromatography on silica (DCM/MeOH,
10:1) and P2 size exclusion chromatography to yield 22 (54 mg, 60%)
20
as a yellow solid after a final lyophilization from water/dioxane. [α]D
1
+85.7 (c 0.25, MeOH). H NMR (500 MHz, CD3OD): δ 8.63 (d,
J = 2.0 Hz, 1H, Ar−H), 8.11 (dd, J = 9.0, 2.0 Hz, 1H, Ar−H), 7.65−
7.55 (m, 4H, Ar−H), 7.48 (dd, J = 8.5, 2.5 Hz, 1H, Ar−H), 6.91 (d,
J = 3.0 Hz, 1H, Ar−H), 5.65 (s, 1H, H-1), 4.14 (m, 1H, H-2), 4.01
(dd, J = 9.5, 3.5 Hz, 1H, H-3), 3.83−3.72 (m, 3H, H-6a, H-4, H-6b),
3.66 (m, 1H, H-5). 13C NMR (125 MHz, CD3OD): δ 152.73, 143.52,
140.14, 134.75, 132.99, 130.01, 127.65, 125.75, 125.57, 119.11, 118.95,
118.79, 111.51, 106.68 (Ar−C), 100.90 (C-1), 76.19 (C-5), 72.37
(C-3), 71.78 (C-2), 68.18 (C-4), 62.69 (C-6). HRMS (ESI) m/z calcd
for C20H19ClN2NaO8 [M + Na]+, 473.0728; found, 473.0728.
q (quartet), or m (multiplet). Assignment of the H and 13C NMR
1
spectra was achieved using 2D methods (COSY, HSQC). ESI mass
spectra were recorded on a Waters micromass ZQ instrument. High-
resolution mass spectra were obtained on an ESI Bruker Daltonics
micrOTOF spectrometer equipped with a TOF hexapole detector.
Microwave-assisted reactions were carried out with CEM Discover and
Explorer. Reactions were monitored by TLC using glass plates coated
with silica gel 60 F254 and visualized by using UV light and/or by
charring with a molybdate solution (a 0.02 M solution of ammonium
cerium sulfate dihydrate and ammonium molybdate tetrahydrate in
aqueous 10% H2SO4) with heating to 150 °C for 5 min. Column
chromatography was performed on a CombiFlash Companion (ISCO,
Inc.) using RediSep normal phase disposable flash columns (silica gel).
Reversed phase chromatography was performed on LiChroprepRP-18
(Merck, 40−63 μm).
4-(5-Nitroindolin-1-yl)phenyl 2,3,4,6-Tetra-O-acetyl-α-D-manno-
pyranoside (47a). In a Schlenk tube, a mixture of 2-dicyclohexyl-
phosphino-2′,4′,6′-triisopropylbiphenyl (X-Phos) (9.1 mg, 0.019 mmol)
and Pd2(dba)3 (3.85 mg, 0.0037 mmol) in dry toluene (3.5 mL) was
stirred for 15 min at 40 °C under argon. Then, 44 (200 mg,
0.37 mmol), Cs2CO3 (364 mg 1.12 mmol), and 5-nitroindoline (45,
91.6 mg, 0.56 mmol) were added. The reaction mixture was degassed in
an ultrasonic bath and stirred for 140 h at 80 °C. The reaction mixture
was diluted with EtOAc (10 mL) and washed with aqueous saturated
NaHCO3 and brine. The aqueous layers were extracted with EtOAc
(3 × 10 mL), and the combined organic layers were dried over Na2SO4,
filtered, and concentrated under reduced pressure. The residue was
purified by chromatography on silica (5−40% gradient of EtOAc in
Compound Purity. Each test compound was purified by
chromatography on silica (dichloromethane (DCM)/MeOH, 10:1)
or reversed-phase chromatography (RP-18 column, H2O/MeOH,
gradient from 0 to 20% MeOH), followed by Bio-Gel P2 (exclusion
limit 1800 Da, Bio-Rad Laboratories) size exclusion chromatography
(elution with water containing up to 20% MeOH at 0.25 mL/min)
prior to HPLC, HRMS, NMR, and activity testing. The purity of all
test compounds was determined by NMR and HPLC [Beckman
Coulter Gold, consisting of pump 126, DAD 168 (190−410 nm), and
autosampler 508. Column: Waters Atlantis T3, 3 μm, 2.1 mm ×
100 mm. A, H2O + 0.1% TFA; B, MeCN + 0.1% TFA. Detection,
270 nm. Gradient, 5 → 95% B (22 min); flow rate, 0.5 mL/min] to be
20
petrol ether) to give 47a (163 mg, 75%) as an orange solid. [α]D
1
+55.0 (c 1.00, CHCl3). H NMR (500 MHz, CDCl3): δ 7.98 (dd, J =
2.3 Hz, 8.9 Hz, 1H, Ar−H), 7.95 (s, 1H, Ar−H), 7.21 (m, 1H, Ar−H),
7.13 (m, 3H, Ar−H), 6.73 (d, J = 8.9 Hz, 1H, Ar−H), 5.55 (dd, J =
10.1, 3.5 Hz, 1H, H-3), 5.50 (d, J = 1.6 Hz, 1H, H-1), 5.44 (dd, J = 3.5,
1.8 Hz, 1H, H-2), 5.38 (t, J = 10.1 Hz, 1H, H-4), 4.28 (dd, J = 12.5,
5.2 Hz, 1H, H-6a), 4.08 (m, 4H, CH2, H-6b, H-5), 3.19 (t, J = 8.6 Hz,
2H, CH2), 2.20, 2.18, 2.04, 2.02 (4s, 12H, OAc). 13C NMR (125 MHz,
CDCl3): δ 170.70, 170.23, 170.19, 169.90 (4 CO), 137.21, 128.40,
126.27, 122.03, 121.32, 117.92, 117.81, 105.52 (Ar−C), 96.36 (C-1),
69.53 (C-5), 69.40 (C-2), 68.98 (C-3), 66.03 (C-4), 62.28 (C-6), 53.85
(CH2), 27.27 (CH2), 21.65, 21.09, 20.92, 20.90 (4 COCH3). MS (ESI)
m/z calcd for C28H31N2O12 [M + H]+, 587.19; found, 587.29.
1
≥95% (for H NMR spectra and HPLC traces, see the Supporting
Information).
2-Chloro-4-(indol-1-yl)phenyl α-D-Mannopyranoside (21). A
resealable Schlenk tube, which was equipped with a magnetic stirring
bar, was charged with 7 (146 mg, 0.25 mmol), CuI (10 mg, 0.05 mmol),
indole (11e, 35.0 mg, 0.30 mmol), K2CO3 (86 mg, 0.63 mmol), and
L-proline (11.5 mg, 0.10 mmol). The vessel was sealed with a rubber
septum, evacuated, and backfilled with argon (this process was repeated
twice). Then, DMSO (1 mL) was added under a stream of argon, the
reaction tube was quickly sealed, and the suspension was stirred at 90 °C
overnight. The reaction mixture was cooled to rt, diluted with EtOAc
(5 mL), and filtered through a plug of Celite. The filtrate was
concentrated in vacuo, and the residue was treated for 2 h with Ac2O/
pyridine (3 mL, 1:2) and a catalytic amount of DMAP. The reaction was
quenched by the addition of MeOH and concentrated, and the residue
was purified by chromatography on silica (petroleum ether/EtOAc, 4:1
to 1:1) to give slightly impure 12 (40 mg, 28%). Compound 12 (40 mg,
0.07 mmol) was dissolved in MeOH (1 mL) and treated at rt with
2-Chloro-4-(5-nitroindolin-1-yl)phenyl 2,3,4,6-Tetra-O-acetyl-α-
D-mannopyranoside (47c). According to the procedure described
for 47a, compound 7 (60 mg, 0.10 mmol) was microwave irradiated
with Cs2CO3 (100 mg 0.30 mmol), X-Phos (4.9 mg, 0.010 mmol),
Pd2(dba)3 (2.21 mg, 0.0020 mmol), and 5-nitroindoline (45, 50.5 mg,
0.30 mmol) in toluene (1 mL) to yield 47c (36 mg, 56%) as an orange
20
1
solid. [α]D +99.6 (c 0.08, CHCl3). H NMR (500 MHz, CDCl3):
δ 8.03 (dd, J = 8.8, 2.3 Hz, 1H, Ar−H), 7.99 (m, 1H, Ar−H),
7.30 (d, J = 2.7 Hz, 1H, Ar−H), 7.26−7.08 (m, 2H, Ar−H), 6.82 (d,
J = 8.9 Hz, 1H, Ar−H), 5.59 (dd, J = 10.1, 3.4 Hz, 1H, H-3), 5.54−
5.46 (m, 2H, H-2, H-1), 5.39 (t, J = 10.1 Hz, 1H, H-4), 4.28 (dd, J =
12.2, 5.1 Hz, 1H, H-6a), 4.21 (m, 1H, H-5), 4.10 (dd, J = 12.3, 2.2 Hz,
4708
dx.doi.org/10.1021/jm300192x | J. Med. Chem. 2012, 55, 4700−4713