Journal of Medicinal Chemistry
Article
The large-scale purification was performed on a CombiFlash with a
UV−vis detector with RediSep columns. The samples were adsorbed
on Celite or silica and loaded into solid load cartridges. An ethyl
acetate/cyclohexane or methanol/methylene chloride gradient was
employed. Fractions were collected based on detection at 254 nm.
The purity of the tested compounds was determined by LC/MS
(UV detection) using two distinct elution conditions (see below) and
was higher than 95%.
HPLC−MS analysis and purification were performed using a
Waters system (2525 binary gradient module, in-line degasser, 2767
sample manager, 2996 photodiode array detector) with a binary
gradient solvent delivery system. This system was coupled with a
Waters Micromass ZQ system with a ZQ2000 quadrupole analyzer.
The ionization was performed by electrospray, and the other
parameters were as follows: source temperature 120 °C, cone voltage
20 V, and continuous sample injection at 0.3 mL/min flow rate. Mass
spectra were recorded in both positive and negative ion modes in the
m/z 100−2000 range and treated with the Mass Lynx 4.1 software.
The eluent was a gradient of 99.9% water/0.1% HCOOH and
99.9% MeCN/0.1% HCOOH or 99.9% water/0.1% HCOOH and
99.9% MeOH/0.1% HCOOH. Each compound was applied to a 100
mm × 4.6 mm (5 μm) WATERS XBridge C18 column equilibrated
with H2O/MeCN or H2O/MeOH 95:5. The following gradients were
the following:
2-(5-(2-Methylthiazol-4-yl)thiophen-2-yl)-3-phenyl-2,3-dihy-
droquinazolin-4(1H)-one (25). To a solution of 2-aminobenzanilide
(212 mg, 1.0 mmol) in methanol (0.3 M) was added 5-(2-methyl-3-
thiazol-4-yl)-2-thiophenecarbaldehyde (209 mg, 1.0 mmol), and the
solution was stirred at room temperature for 24 h. The precipitate was
filtered and washed with a small quantity of MeOH to give the imino
compound (252 mg, 62%) as a yellow solid. To a mixture of NaH in
anhydrous THF (0.5 mL) was added dropwise a solution of the imino
compound in anhydrous THF (1.1 mL) at 0 °C. After 1 h at 0 °C, the
reaction was quenched with a saturated solution of NaHCO3 (1 mL).
The mixture was partitioned between a saturated solution of NaHCO3
(10 mL) and CH2Cl2 (10 mL). The aqueous layer was extracted with
CH2Cl2 (2 × 10 mL). The combined organic layers were washed with
brine (10 mL), dried over anhydrous MgSO4, filtered, and
concentrated in vacuum. The purification by silica gel chromatography
(ethyl acetate/cyclohexane, 1/1) yielded the expected compound 25
(34 mg, 68%) as a yellow solid. 1H NMR (400 MHz, CDCl3) δ (ppm)
= 2.67 (s, 3H), 6.20 (s, 1H), 6.65 (d, J = 8.1 Hz, 1H), 6.78 (d, J = 3.8
Hz, 1H), 6.85−6.91 (m, 1H), 7.06 (s, 1H), 7.08 (d, J = 3.8 Hz, 1H),
7.18−7.24 (m, 1H), 7.26−7.33 (m, 5H), 8.00 (dd, J = 7.8 Hz, J′ = 1.6
Hz, 1H). 13C NMR (100 MHz, CDCl3) δ (ppm) = 19.2, 70.9, 111.8,
115.7, 117.1, 120.0, 123.1, 126.8, 127.0, 127.3, 129.0, 129.1, 134.0,
138.6, 140.5, 143.4, 145.0, 148.9, 162.5, 166.4. MS (ESI) [M + H]+ =
404.0. LC/MS (X-bridge 100 mm × 4.6 mm): tR = 7.98 min, m/z
404.0 ([M + H+]).
Gradient A: Samples were eluted by increasing MeOH to 100% (25
1-Methyl-2-(5-methylthiophen-2-yl)-3-phenyl-2,3-dihydro-
quinazolin-4(1H)-one (62). To a mixture of NaH (19 mg, 0.475
mmol) in anhydrous THF (0.3 M) was added dropwise a solution of 1
(100 mg, 0.312 mmol) in anhydrous THF (0.5M) at 0 °C. After 30
min, iodomethane (21 μL, 0.337 mmol) was added dropwise. After 10
min, the solution was warmed to room temperature and stirred for 3 h.
The reaction was then quenched with a saturated solution of
NaHCO3. The aqueous layer was then repeatedly extracted with
CH2Cl2. The combined organic layers were then washed with a 1 M
solution of HCl (2 × 10 mL), dried over anhydrous Na2SO4, filtered,
and concentrated in vacuum. The purification by silica gel
chromatography (ethyl acetate/cyclohexane, 3/7) of the crude mixture
min), then staying at 100% (5 min).
Gradient B: Samples were eluted by increasing MeOH to 90% (24
min), then to 100% (1 min), and staying at 100% (5 min).
Gradient C: Samples were eluted by increasing MeOH to 80% (24
min), then to 100% (1 min), and staying at 100% (5 min).
Gradient D: Samples were eluted by increasing MeCN to 100% (25
min), then staying at 100% (1 min).
Gradient E: Samples were eluted by increasing MeCN to 90% (24
min), then to 100% (1 min), and staying at 100% (5 min).
Gradient F: Samples were eluted by increasing MeCN to 80% (24
min), then 100% (1 min) and stay at 100% (5 min).
Gradient G: Samples were eluted by increasing MeCN to 60% (24
min), then to 100% (1 min), and staying at 100% (5 min).
HPLC (chiral) analyses were performed on a system equipped with
a binary gradient solvent delivery system (LC-20AB, Shimadzu), a SIL-
20A autosampler (Shimadzu), and a photodiode array detector (SPD-
20A, Shimadzu).
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yielded the expected compound (89 mg, 85%) as a white solid. H
NMR (400 MHz, DMSO) δ (ppm) = 2.34 (s, 3H), 2.93 (s, 3H), 5.91
(s, 1H), 6.50 (d, J = 2.4 Hz, 1H), 6.64−6.67 (m, 2H), 6.96 (t, J = 7.6
Hz, 1H), 7.25−7.39 (m, 5H), 7.42−7.47 (m, 1H), 8.11 (dd, J = 1.6
Hz, J′ = 7.6 Hz, 1H). 13C NMR (100 MHz, DMSO) δ (ppm) = 15.2,
35.9, 77.9, 112.8, 117.5, 119.0, 124.0, 126.6, 126.7, 126.9, 128.9, 128.9,
134.0, 137.0, 140.3, 140.5, 146.3, 161.8. MS (ESI) [M + H]+ = 334.9.
LC/MS (X-bridge 100 mm × 4.6 mm): tR = 8.20 min, m/z 334.9 ([M
+ H+]). Gradient A: tR = 21.15 min. Gradient D: tR = 17.99 min. IR
(neat, cm−1) 3063, 2915, 2856, 1670, 1608, 1531, 1468, 1226, 761,
693. HRMS m/z [(M + H)+] calcd for C20H19N2OS 335.1204, found
335.1218.
NMR experiments were performed on a Bruker Avance 400
1
Ultrashield spectrometer. H NMR and 13C spectra were recorded at
room temperature at 400 and 100 MHz, respectively, samples were
dissolved in DMSO-d6 at a concentration of approximately 5 mM. The
DMSO singlet signal was set up at 2.50 ppm. Chemical shifts are given
in ppm and the coupling constants in Hz. Spectral data are consistent
with assigned structures.
2-(5-Ethylthiophen-2-yl)-1-methyl-3-phenyl-2,3-dihydroqui-
nazolin-4(1H)-one (66). To a mixture of NaH (15 mg, 0.375 mmol)
in anhydrous THF (0.3 M) was added dropwise a solution of 17 (100
mg, 0.299 mmol) in anhydrous THF (0.5 M) at 0 °C. After 30 min,
iodomethane (20 μL, 0.321 mmol) was added dropwise. After 10 min,
the solution was warmed to room temperature and stirred for 3 h. The
reaction was then quenched with a saturated solution of NaHCO3.
The aqueous layer was then repeatedly extracted with CH2Cl2. The
combined organic layers were then washed with a 1 M solution of HCl
(2 × 10 mL), dried over anhydrous Na2SO4, filtered, and concentrated
in vacuum. The purification by silica gel chromatography (ethyl
acetate/cyclohexane, 3/7) of the crude mixture yielded the expected
compound (87 mg, 84%) as a white solid. 1H NMR (400 MHz,
CDCl3) δ (ppm) = 1.21 (t, J = 7.5 Hz, 3H), 2.70 (q, J = 7.5 Hz, 2H),
2.94 (s, 3H), 5.92 (s, 1H), 6.51−6.54 (m, 1H), 6.65−6.68 (m, 2H),
6.95 (t, J = 8.1 Hz, 1H), 7.24−7.47 (m, 6H), 8.10 (dd, J = 7.7 Hz, J′ =
1.6 Hz, 1H). 13C NMR (100 MHz, CDCl3) δ (ppm) = 15.5, 23.4,
36.2, 78.2, 113.0, 117.7, 119.2, 122.3, 126.7, 126.8, 127.1, 129.1, 129.2,
134.2, 136.9, 140.7, 146.5, 162.0. MS (ESI) [M + H]+ = 349.1. LC/MS
(X-bridge 100 mm × 4.6 mm): tR = 8.77 min, m/z 349.1 ([M + H+]).
Gradient A: tR = 21.95 min. Gradient D: tR = 19.02 min. IR (neat,
Physicochemical properties were calculated using MarvinSketch
5.4.1.1 software (ChemAxon).
High-resolution mass spectrometry (HRMS) was performed using
the Imagif platform (CNRS, Gif-sur-Yvette, France), and results were
recorded on a ESI/TOF LCP premier XE mass spectrometer (Waters)
using flow injection analysis mode.
2-(5-Ethylthiophen-2-yl)-3-phenyl-2,3-dihydroquinazolin-
4(1H)-one (17). To a solution of 2-aminobenzanilide (212 mg, 1.0
mmol) in methanol (0.2 M) was added 5-ethylthiophen-2-carbox-
aldehyde (125 μL, 1.0 mmol), and the solution was stirred at room
temperature until complete consumption of starting materials. The
precipitate was filtered to give the title compound (147 mg, 52%) as a
1
beige solid. H NMR (400 MHz, DMSO-d6) δ (ppm) = 1.13 (t, J =
7.6 Hz, 3H), 2.67 (q, J = 7.6 Hz, 2H), 6.42 (d, J = 2.4 Hz, 1H), 6.58
(d, J = 3.2 Hz, 1H), 6.74−6.83 (m, 3H), 7.24 (t, J = 7.2 Hz, 1H),
7.30−7.40 (m, 5H), 6.64 (d, J = 2.8 Hz, 1H), 7.73 (d, J = 7.2 Hz, 1H).
13C NMR (100 MHz, DMSO-d6) δ (ppm) = 15.5, 22.6, 69.6, 115.1,
115.4, 117.9, 122.6, 126.0, 126.2, 126.3, 127.9, 128.6, 133.7, 140.4,
141.6, 146.2, 146.6, 161.4. MS (ESI) [M + H]+ = 335.1. LC/MS (X-
bridge 100 mm × 4.6 mm): tR = 7.57 min, m/z 335.1 ([M + H+]).
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dx.doi.org/10.1021/jm4002346 | J. Med. Chem. 2013, 56, 3404−3413