B.-R. Kang et al. / Bioorg. Med. Chem. 21 (2013) 6956–6964
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2H, J = 6.2 Hz, –CH2–), 3.45 (b, 2H, –NCH2–), 3.73(b, 2H, –NCH2–),
3.79 (t, 2H, J = 6.2 Hz, –CH2–), 3.92 (s, 3H, –OCH3), 6.59 (s, 1H,
Ar-H), 6.62 (d, 1H, J = 7.6 Hz, –CH@), 7.00 (s, 1H, Ar-H), 7.12 (d,
1H, J = 7.6 Hz, @CH–), 7.47 (s, 1H, Ar-H), 7.50 (s, 1H, Ar-H), 7.57
(t, 1H, Ar-H), 13.07 (s, 1H, Ar-OH). HRMS: Calcd for C25H26N3NaO5
[M+Na]+: 550.0954; Found: 550.0966.
residual was purified though silica gel column chromatography
(CHCl3/MeOH = 20:1, v/v) to produce 0.13 g of white solid. Yield
80.0%; 1H NMR (400 MHz, CDCl3), d: 1.71 (b, 6H, –CH2–), 2.67 (d,
6H, J = 4.0 Hz, –NCH2–), 2.85 (b, 2H, –NCH2–), 3.45 (b, 2H, –
NCH2–), 3.73 (d, 2H, J = 5.6 Hz, –COCH2–), 3.81 (b, 4H, –CH2O),
3.91 (s, 3H, –OCH3), 6.53 (d, 1H, J = 8.0 Hz, –CH@), 6.61 (s, 1H,
Ar-H), 7.09 (d, 1H, J = 8.0 Hz, @CH–), 7.47 (d, 1H, J = 1.2 Hz, Ar-
H), 7.48 (s, 1H, Ar-H), 7.50 (s, 1H, Ar-H), 7.57 (t, 1H, J = 7.8 Hz,
Ar-H), 13.02 (s, 1H, Ar-OH). HRMS: Calcd for C29H35N4O6 [M+H]+:
535.2557; Found: 535.2576.
4.1.31. Compound 10a 5-acryloylamino-6,8-dimethoxy-2-(3-
(piperidin-1-ylcarbonyl)phenyl)isoquinoline-1(2H)-one
The nitro group in 8a was reduced with iron powder. The ob-
tained amine (0.07 g, 0.16 mmol) was dissolved in dried THF
(5 ml) and TEA (0.1 ml) was added. The solution was cooled to
0 °C, added dropwise acryloyl chloride (0.05 ml, 0.30 mmol) in
anhydrate THF (5 ml). The resulted mixture was stirred at 0 °C
for 30 min, then at rt for another 4 h. The volatile was removed un-
der vacuum and the residue was dissolved in chloroform (20 ml).
The organic layer was washed with saturated Na2CO3 solution
(20 ml ꢂ 3), hydrochloric acid solution (2 M, 20 ml ꢂ 3) and brine
(20 ml), dried over anhydrous sodium sulfate. The crude product
was purified though silica gel column chromatograph (CHCl3/
MeOH = 30:1, v/v) to give a light-yellow solid (0.04 g). Yield
54.2%; 1H NMR (300 MHz, CDCl3), d: 1.42–1.80 (m, 6H, 3ꢂ CH2),
3.40 (b, 2H, N–CH2), 3.61 (b, 2H, N–CH2), 3.90 (s, 6H, O–CH3),
5.81 (dd, 1H, J = 10.2, 1.2 Hz, CH@), 6.26 (dd, 1H, J = 16.9,
10.2 Hz, @CH2), 6.45 (dd, 1H, J = 16.9, 1.2 Hz, @CH2), 6.50 (m, 1H,
Ar-CH), 6.61(s, 1H, Ar-H), 7.12 (d, 1H, J = 7.6 Hz, Ar-CH), 7.38–
7.55 (m, 4H, Ar-H). HRMS: Calcd for C26H27N3NaO5 [M+Na]+:
484.1848; Found: 484.1856.
4.1.35. Compound 13 6,8-dimethoxy-3,4-dihydro-isoquinolin-1-
(2H)-one
To the solution of compound 1 (2.00 g, 10.4 mmol) in TFA
(30 ml) was added to NaN3 (1.95 g, 30.0 mmol) in portions. The
reaction mixture was refluxed with stirring for 10 h. The solvent
was removed and the residue was dissolved in ethyl acetate. The
organic layer was washed with water and brine, dried over anhy-
drous sodium sulfate. The crude product was refined though silica
gel column chromatography (chloroform/methanol = 40:1, v/v) to
give brown solid (1.08 g). Yield 50.1%; 1H NMR (400 MHz, CDCl3),
d: 2.91 (t, 2H, J = 6.4 Hz, –CH2–), 3.45 (t, 2H, J = 5.2 Hz, –CH2–),
3.86 (s, 3H, –OCH3), 3.92 (s, 3H, –OCH3), 6.33 (s, 1H, Ar-H), 6.42
(s, 1H, Ar-H), 6.83 (s, 1H, –NH). MS: 208.1 [M+H]+.
4.1.36. Compound 14 3,4-dihydro-6,8-dimethoxy-2-(3-
(piperidin-1-ylcarbonyl) phenyl)-isoquinolin-1-(2H)-one
From 13. Yield 73.6%; 1H NMR (400 MHz, CDCl3), d: 1.67 (b, 6H,
–CH2–), 3.05 (t, J = 6.0 Hz, 2H, –CH2), 3.42 (br, 2H, N–CH2), 3.72 (br,
2H, N–CH2), 3.88 (s, 3H, –OCH3), 3.90 (s, 3H, –OCH3), 3.95 (t, 2H, J =
6.4 Hz, –CH2), 6.35 (s, 1H, Ar-H), 6.44 (s, 1H, Ar-H), 7.21 (d, J =
7.2 Hz, 1H, Ar-H), 7.39 (d, J = 7.6 Hz, 1H, Ar-H), 7.34 (s, 1H, Ar-H),
7.46–7,42 (t, J = 7.2 Hz, 1H, Ar-H). HRMS: Calcd for C23H26N2NaO4
[M+Na]+: 417.1790; Found: 417.1803.
4.1.32. Compound 10b 5-acryloylamino-8-hydroxy-6-methoxy-
2-(3-(piperidin-1-ylcarbonyl)phenyl)isoquinoline-1(2H)-one
Yield 71.5%; 1H NMR (400 MHz, CDCl3), d: 1.58 (b, 2H, –CH2–),
1.71 (b, 4H, –CH2–), 3.45 (b, 2H, N–CH2), 3.76 (b, 2H, N–CH2),
3.92 (s, 3H, –OCH3), 5.80 (dd, 1H, J = 10.2, 1.2 Hz, CH@), 6.22 (dd,
1H, J = 16.9, 10.2 Hz, @CH2), 6.47 (dd, 1H, J = 16.9, 1.2 Hz, CH@CH2),
6.60 (s, 1H, Ar-H), 6.66 (d, 1H, J = 7.6 Hz, –CH@), 7.00 (s, 1H, Ar-H),
7.12 (b, 1H, J = 7.2 Hz, @CH–), 7.48 (d, 1H, J = 3.2 Hz, Ar-H), 7.50 (s,
1H, Ar-H), 7.56 (q, 1H, Ar-H), 13.07 (s, 1H, Ar-OH). HRMS: Calcd for
4.1.37. Compound 15 3,4-dihydro-8-hydroxy-6-methoxy-2-(3-
(piperidin-1-ylcarbonyl)phenyl)-isoquinolin-1-(2H)-one
From 14. Yield 90.0%; 1H NMR (400 MHz, CDCl3), d: 1.71 (b, 6H,
–CH2–), 3.09 (t, 2H, J = 6.4 Hz, –CH2–), 3.47 (b, 2H, –NCH2–), 3.71
(b, 2H, –NCH2–), 3.85 (s, 3H, –OCH3), 3.97 (t, 2H, J = 6.4 Hz, –
CH2–), 6.29 (s, 1H, Ar-H), 6.37 (d, J = 2.0 Hz, 1H, Ar-H), 7.32 (d, J =
7.2 Hz, 1H, Ar-H), 7.42 (s, 1H, Ar-H), 7.45 (d, J = 7.2 Hz, 1H, Ar-H),
7.48 (t, J = 7.6 Hz, 1H, Ar-H), 12.54 (br, 1H, Ar-OH). HRMS: Calcd
for C22H24N2NaO4 [M+Na]+: 403.1634; Found: 403.1643.
C
25H25N3NaO5 [M+Na]+: 470.1692; Found: 470.1711.
4.1.33. Compound 11 5-[4-(4-methylpiperazin-1-
ylcarbonyl)phenyl]urea-8-hydroxy-6-methoxy-2-(3-(piperidin-
1-ylcarbonyl)phenyl)isoquinoline-1(2H)-one
4-(4-Methylpiperazin-1-ylcarbonyl)phenylisocyanate was pre-
pared as our reported method.32 Arylamine, reduced from 8b,
was directly added to the isocyanate, and the mixture was stirred
at room temperature for 2 h. The solvent was removed and flash
chromatograph of the residue over silica gel, using chloroform/
methanol (10:1), produce 11 as white solids. Yield 44.6%; 1H
NMR (400 MHz, CDCl3), d: 1.59 (s, 2H, –CH2–), 1.72 (s, 4H, –CH2–
), 2.40 (s, 3H, NCH3), 2.54 (b, 4H, –NCH2–), 3.46 (b, 2H, –NCH2–),
3.67 (d, 1H, J = 10.8 Hz, @CH–), 3.76 (b, 4H, –NCH2–), 3.79 (s, 2H,
–NCH2–), 3.87 (s, 3H, –OCH3), 6.55 (s, 1H, Ar-H), 6.67 (d, 1H, J =
6.4 Hz, –CH@), 6.96 (s, 1H, Ar-H), 7.31 (d, 2H, J = 8.8 Hz, Ar-H),
7.41 (d, 2H, J = 8.8 Hz, Ar-H), 7.45 (d, 1H, J = 9.2 Hz, Ar-H), 7.49
(s, 1H, Ar-H), 7.55 (m, 1H, Ar-H), 12.96 (s, 1H, Ar-OH). HRMS: Calcd
for C35H39N6O6 [M+H]+: 639.2931; Found: 639.2957.
4.2. Biological materials and methods
4.2.1. In vitro antiproliferative assay
Cellular chemosensitivity was determined by using a modi-
fied MTT (3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazo-
lium bromide) method assay in vitro. In brief, A431 or A549
cells in 100 ll culture medium were seeded into 96-well micro-
plates respectively and incubated at 37 °C for 24 h prior to drug
exposure. Cell numbers were titrated to keep control cells grow-
ing in the exponential phase throughout the 72 h incubation
period. Cells were treated with final concentrations of 100.0,
10.0, 1.0, and 0.1
lM of tested compounds simultaneously and
incubated for 72 h and then 20
ll of MTT solution (5 mg/ml in
4.1.34. Compound 12 5-(3-(4-morpholinyl)propionylamino)-8-
hydroxy-6-methoxy-2-(3-(piperidin-1-
ylcarbonyl)phenyl)isoquinoline-1(2H)-one
PBS) was added to each well and incubated for 4 h. The formed
blue formazan crystals were pelleted to the bottom of the well
by centrifugation, separated from the supernatant, and dissolved
The mixture of 9 (0.13 g, 0.25 mmol), potassium iodide (0.083 g,
0.50 mmol) and acetonitrile (10.0 ml) was refluxed for 2 h under
nitrogen and cooled to room temperature. Then morpholine
(0.04 ml, 0.50 mmol) was added. The mixture was refluxed for
6 h under nitrogen. The solvent was removed under vacuum. The
in 200 ll of DMSO. The optical density at 570 nm was deter-
mined by an ELISA reader. Three separate experiments with
triplicate data were performed to obtain mean cell viability.
The IC50 values were calculated according to the inhibition
ratios.