February 2010
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crystalline solid.
3ꢂOCH3), 5.96 (s, 2H, –OCH2–), 6.39—6.48 (d, 1H, ꢃCH–CO–,
Jꢃ15.3 Hz), 6.76 (s, 2H, aromatic), 6.78 (d, 1H, aromatic), 6.86 (d, 1H, aro-
matic), 7.36 (br s, 1H, aromatic), 7.62—7.67 (d, 1H, ꢃCH, Jꢃ15.3 Hz). IR
(KBr) cmꢄ1: 1127, 1656, 3266. ESI m/z: 358 [MꢅH]ꢅ; 380 [MꢅNa]ꢅ.
(E)-N-(3,4-Methylenedioxyphenyl)-3-(4-acetoxy-3,5-dimethoxyphenyl)-
acrylamide (17): Yieldꢃ62%. Oil. 1H-NMR (CDCl3) d: 2.35 (s, 3H,
OCOCH3), 3.84 (s, 6H, 2ꢂOCH3), 5.9 (s, 2H, –OCH2–), 6.41—6.46 (d, 1H,
ꢃCHCO, Jꢃ15 Hz), 6.75 (s, 2H, aromatic), 6.78 (d, 1H, aromatic), 6.87 (br
d, 1H, aromatic), 7.61—7.66 (d, 1H, CHꢃC, Jꢃ15.6 Hz), 8.01 (s, 1H, aro-
matic). IR (KBr) cmꢄ1: 1199, 1499, 1560, 1753. ESI m/z: 408 [MꢅNa]ꢅ,
793 [2MꢅNa]ꢅ.
(E)-N-(3,4,5-Trimethoxyphenyl)-3-(3,4,5-trimethoxyphenyl)acrylamide
(20): Yieldꢃ57%. Oil. 1H-NMR (CDCl3) d: 3.9 (s, 3H, OCH3), 3.89 (s, 6H,
2ꢂOCH3), 3.84 (s, 9H, 3ꢂOCH3), 6.7 (s, 4H, aromatic), 6.50—6.56 (d, 1H,
ꢃCH–CO–, Jꢃ15.3 Hz), 7.63—7.68 (d, 1H, ꢃCH, Jꢃ15.3 Hz). ESI m/z:
426 [MꢅNa]ꢅ
3,4-Dihydro-6,7-methylenedioxy-4-(3,4,5-trimethoxyphenyl)coumarin
(12): Yieldꢃ34%. mpꢃ188—190 °C. 1H-NMR (CDCl3) d: 2.96—3.02 (two
pairs of dd, 2H, 3-CH2, Jꢃ6, 8.1 Hz), 3.81 (s, 6H, 3ꢀ, 5ꢀ-OCH3), 3.84 (s, 3H,
4ꢀ-OCH3), 4.13—4.17 (t, 1H, 4-CH, Jꢃ6.75 Hz), 5.97 (s, 2H, –O–CH2–O–),
6.35 (s, 2H, 2ꢀ, 6ꢀ-CH, aromatic), 6.44 (s, 1H, 5-CH, aromatic), 6.66 (s, 1H,
8-CH, aromatic). 13C-NMR (CDCl3) d: 37.37, 41.47, 56.73, 56.73, 61.08,
99.46, 99.46, 102.05, 105.59, 107.60, 118.32, 136.46, 138.57, 144.91,
146.67, 148.07, 154.24, 154.24, 167.63. IR (KBr) cmꢄ1: 1654, 1752. ESI
m/z: 358 [Mꢅ], 359 [Mꢅꢅ1], 343 [MꢅꢄCH3].
3,4-Dihydro-7-methoxy-4-(3,4,5-trimethoxyphenyl)coumarin (24): Yieldꢃ
16%. mpꢃ102—104 °C. H-NMR (CDCl3) d: 2.94—3.01 (two pairs of dd,
1
2H, 3-CH2, Jꢃ7.5, 9 Hz), 3.59 (s, 3H, 7-OCH3), 3.77 (s, 3H, 4ꢀ-OCH3), 3.80
(s, 6H, 3ꢀ, 5ꢀ-OCH3), 4.74—4.80 (t, 1H, 4-CH, Jꢃ8 Hz), 6.31 (dd, 1H, 6-
CH, aromatic, Jꢃ8.1, 2.4 Hz), 6.34 (d, 1H, 8-CH, aromatic, Jꢃ2.1 Hz), 6.45
(s, 2H, 2ꢀ, 6ꢀ of aromatic), 6.90—6.93 (d, 1H, 5-CH, aromatic, Jꢃ8.1 Hz).
13C-NMR (CDCl3) d: 40.19, 40.81, 51.75, 55.79, 56.61, 61.06, 99.97,
106.10, 106.21, 107.37, 124.41, 128.80, 137.31, 139.71, 153.42, 156.19,
158.40, 173.06. IR (KBr) cmꢄ1: 842, 1130, 1594, 1738. ESI m/z: 344 [Mꢅ],
345 [Mꢅ1]ꢅ.
(E)-N-(3,4,5-Trimethoxyphenyl)-3-(4-hydroxy-3,5-dimethoxyphenyl)acryl-
1
amide (21): Yieldꢃ55%. Oil. H-NMR (CDCl3) d: 2.31 (s, 3H, OCOCH3),
3.87 (s, 6H, 2ꢂOCH3), 3.82 (s, 3H, OCH3), 3.81 (s, 6H, 2ꢂOCH3), 5.8 (s,
1H, NH), 6.41—6.46 (d, 1H, ꢃCH–C–, Jꢃ15.3 Hz), 6.71 (s, 4H, aromatic),
6.7 (s, 2H, aromatic). ESI m/z: 432 [MꢅH]ꢅ.
3,4-Dihydro-6,7-methylenedioxy-4-(2-acetyloxy-3,5-dimethoxyphenyl)-
coumarin (14): Yieldꢃ98%. mpꢃ171—173 °C. 1H-NMR (CDCl3) d: 2.05
(s, 3H, OCOCH3), 2.96—3.04 (dd, 2H, 3-CH2, Jꢃ6, 8.1 Hz), 3.77 (s, 6H, 3ꢀ,
5ꢀ-OCH3), 4.15—4.17 (t, 1H, 4-CH, Jꢃ6.6 Hz), 5.97 (s, 2H, –O–CH2–O–),
6.38 (s, 2H, 2ꢀ, 6ꢀ-CH, aromatic), 6.45 (s, 1H, 5-CH, aromatic), 6.66 (s, 1H,
8-CH, aromatic). 13C-NMR (CDCl3) d: 20.64, 37.28, 41.65, 56.64, 56.64,
99.50, 102.11, 104.78, 107.64, 117.97, 128.92, 139.34, 144.94, 146.66,
148.15, 153.15, 167.47, 168.76. IR (KBr, cmꢄ1): 1130, 1460, 1737, 1762.
ESI m/z: 409 [MꢅNa]ꢅ; negative mode, 385 [MꢄH]ꢄ.
General Procedure for Synthesis of Lactam Analogues of PDT (18,
19, 22, 23) 600 mg Amide 16 (1.6 mmol) was stirred in 2 ml trifluoroacetic
acid at room temperature for 72 h. After completion, the reaction mixture
was diluted with water, extracted with chloroform, and washed with 5%
NaHCO3 solution (3ꢂ20 ml). The organic layer was dried over anhydrous
Na2SO4 and evaporated in vacuo to obtain a residue. The residue thus ob-
tained was purified through a silica gel column by eluting with hexane–ethyl
acetate. The desired amide 18 was obtained as a creamy white solid.
3,4-Dihydro-6,7-methylenedioxy-4-(3,4,5-trimethoxyphenyl)quinolin-
2(1H)-one (18): Yieldꢃ45%. mpꢃ212—214 °C. 1H-NMR (CDCl3) d:
2.84—2.88 (two pairs of dd, 2H, 3-CH2, Jꢃ3.3, 5.7 Hz), 3.81 (s, 6H, 3ꢀ, 5ꢀ-
OCH3), 3.84 (s, 3H, OCH3), 4.08—4.13 (t, 1H, 4-CH, Jꢃ4.4 Hz), 5.92 (s,
2H, –O–CH2–O–), 6.38 (s, 2H, 2ꢀ, 6ꢀ-CH, aromatic), 6.39 (s, 1H, aromatic),
6.41 (s, 1H, aromatic). 13C-NMR (CDCl3) d: 38.94, 42.78, 56.68, 56.68,
61.10, 98.10, 101.63, 105.78, 108.74, 119.59, 129.15, 131.10, 131.76,
137.55, 144.09, 147.69, 154.05, 167.97, 170.88. IR (KBr) cmꢄ1: 1655,
1686, 1993. ESI m/z: 358 [MꢅH]ꢅ; 380 [MꢅNa]ꢅ; negative mode, 356
[MꢄH]ꢄ.
3,4-Dihydro-6,7-methylenedioxy-4-(4-hydroxy-3,5-dimethoxyphenyl)-
quinolin-2(1H)-one (19): Yieldꢃ34.5%. mpꢃ262—264 °C. 1H-NMR
(CDCl3) d: 2.83—2.87 (dd, 2H, 3-CH2, Jꢃ4.2, 4.8 Hz), 3.86 (s, 6H, 3ꢀ, 5ꢀ-
OCH3), 4.07—4.12 (t, 1H, 4-CH, Jꢃ7.2 Hz), 5.92 (d, 2H, –O–CH2–O–, Jꢃ
1.8 Hz), 6.28 (s, 1H, aromatic), 6.38 (s, 1H, aromatic), 6.41 (s, 2H, 2ꢀ, 6ꢀ-CH,
aromatic). IR (KBr) cmꢄ1: 1544, 1638, 1655. ESI m/z: 366 [MꢅNa]ꢅ.
3,4-Dihydro-5,6,7-trimethoxy-4-(3,4,5-trimethoxyphenyl)quinolin-2(1H)-
one (22): Yieldꢃ66%. Oil. 1H-NMR (CDCl3) d: 2.82—3.01 (two pairs of
dd, 2H, 3-CH2, Jꢃ7.2, 8.1 Hz), 3.77 (s, 3H, OCH3), 3.80 (s, 6H, 3ꢀ, 5ꢀ-
OCH3), 3.84 (s, 3H, OCH3), 3.86 (s, 3H, OCH3), 3.88 (s, 3H, OCH3), 4.52—
4.54 (br d, 1H, 4-CH, Jꢃ5.1 Hz), 6.19 (s, 1H, aromatic), 6.37 (s, 2H, 2ꢀ, 6ꢀ-
CH, aromatic), 8.06 (s,1H, exchangeable, amide NH). IR (KBr) cmꢄ1: 1655,
3399. ESI m/z: 426 [MꢅNa]ꢅ; negative mode, 402 [MꢄH]ꢄ.
3,4-Dihydro-5,7-dimethoxy-4-(3,4,5-trimethoxyphenyl)coumarin
(25):
Yieldꢃ29%. mpꢃ146—148 °C. 1H-NMR (CDCl3) d: 2.98—3.0 (br s, 2H,
3-CH2,), 3.78 (s, 6H, 3ꢀ, 5ꢀ-OCH3), 3.82 (s, 3H, 4ꢀ-OCH3), 4.48—4.51
(br t, 1H, 4-CH), 6.29 (s, 1H, aromatic), 6.32 (s, 1H, aromatic), 6.34 (s, 2H,
2ꢀ, 6ꢀ-CH, aromatic). 13C-NMR (CDCl3) d: 35.19, 37.32, 55.89, 56.19,
56.19, 56.59, 60.98, 94.72, 95.69, 104.95, 106.76, 108.07, 137.70, 138.12,
153.54, 153.91, 157.94, 161.27, 167.80. IR (KBr) cmꢄ1: 834, 1128, 1626.
ESI m/z: 397 [MꢅNa]ꢅ; 413 [MꢅK]ꢅ.
3,4-Dihydro-6,7-dimethoxy-4-(3,4,5-trimethoxyphenyl)coumarin
(26):
Yieldꢃ24%. mpꢃ145—147 °C. 1H-NMR (CDCl3) d: 2.92—3.11 (two pairs
of dd, 2H, 3-CH2, Jꢃ7.2, 8.0 Hz), 3.77 (s, 3H, OCH3), 3.81 (s, 6H, 3ꢀ, 5ꢀ-
OCH3), 3.84 (s, 3H, OCH3), 3.90 (s, 3H, OCH3), 4.19—4.23 (t, 1H, 4-CH,
Jꢃ6.5 Hz), 6.35 (s, 2H, 2ꢀ, 6ꢀ-CH, aromatic), 6.51 (s, 1H, aromatic), 6.70 (s,
1H, aromatic). 13C-NMR (CDCl3) d: 37.85, 41.40, 56.63, 56.81, 56.81,
57.11, 61.01, 102.32, 105.93, 112.31, 116.93, 136.76, 146.28, 146.74,
150.34, 154.30, 167.51. IR (KBr) cmꢄ1: 1125, 1164, 1510, 1756. ESI m/z:
397.1 [MꢅNa]ꢅ, 771.0 [2MꢅNa]ꢅ, negative mode, 372.9 [MꢄH]ꢄ.
3,4-Dihydro-7-methoxy-4-(3,4,5-trimethoxyphenyl)-2H-naphtho[2,3-
b]pyran-2-one (27): Yieldꢃ16%. Oil. 1H-NMR (CDCl3) d: 3.10—3.23 (br d,
2H, 3-CH2), 3.72 (s, 6H, 3ꢀ, 5ꢀ-OCH3), 3.77 (s, 3H, OCH3), 3.91 (s, 3H,
OCH3), 4.82—4.85 (br t, 1H, 4-CH), 6.31 (s, 2H, aromatic), 7.15—7.77 (m,
5H, aromatic). 13C-NMR (CDCl3) d: 22.94, 37.91, 55.71, 56.66, 56.66,
60.98, 105.18, 107.70, 112.19, 114.79, 118.25, 120.31, 124.89, 126.66,
128.94, 132.83, 136.66, 148.75, 154.29, 157.72, 167.30. IR (KBr, cmꢄ1):
784, 1260, 2927. ESI m/z: 394 [M]ꢅ, 395 [Mꢅ1]ꢅ.
3,4-Dihydro-5,6,7-trimethoxy-4-(4-hydroxy-3,5-dimethoxyphenyl)-
quinolin-2(1H)-one (23): Yieldꢃ36.7%. Oil. 1H-NMR (CDCl3) d: 2.85—
2.94 (dd, 2H, 3-CH2), 3.71(s, 3H, OCH3), 3.79 (s, 3H, OCH3), 3.82 (s, 3H,
OCH3), 3.84 (s, 3H, OCH3), 3.87 (s, 3H, OCH3), 4.51 (m, 1H, 4CH), 5.38
(br s, 1H exchangeable, NH), 6.36 (s, 1H, aromatic), 6.80 (s, 2H, aromatic).
ESI mass (MeOH): 390 [MꢅH]ꢅ; 412 [MꢅNa]ꢅ.
Cell Assays Human cancer cell lines were American type of cell culture
collection (ATCC) obtained from NCCS Pune, India. Cells were cultured in
DMEM with HEPES-25 mM, 0.22% NaHCO3, and 10% FBS.
3ꢀ,4ꢀ-Dihydro-4ꢀ-(3,4,5-trimethoxyphenyl)estra-1(10),2,4-trieno[3,2-
b]pyran-2ꢀ,17-dione (28): Yieldꢃ58%. Oil. 1H-NMR (CDCl3) d: 0.89 (s,
3H, 18-CH3), 1.39—2.25 (m, 15H, all the CH2, CH of steroidal ring), 2.95—
3.04 (br dd, 2H, 3-CH2), 3.79 (s, 6H, 3ꢀ, 5ꢀ-OCH3), 3.84 (s, 3H, OCH3),
4.20—4.22 (br t, 1H, 4-CH), 6.33 (s, 1H, aromatic), 6.37 (s, 1H, aromatic),
6.87 (d, 1H, aromatic, Jꢃ3.3 Hz), 6.96 (s, 1H, aromatic). ESI m/z: 491
[MꢅH]ꢅ, 513 [MꢅNa]ꢅ.
In vitro cytotoxicity testing was performed as per reported method.14)
2ꢂ103 cells/well were incubated in 5% CO2 incubator for 24 h to enable
them to adhere properly to the 96 well polystyrene microplate (Grenier, Ger-
many). Test compound dissolved in dimethyl sulfoxide (DMSO, Merck,
Germany), in at least five concentrations, was added into the wells and left
for 4 h. After the incubation, the compound plus media was replaced with
fresh media and the cells were incubated in the CO2 incubator at 37 °C for
another 48 h. The concentration of DMSO was always kept below 1.25%,
which was found to be non-toxic to cells. Then, 10 ml MTT was added to
each well and plates were incubated at 37 °C for 4 h. 100 ml DMSO was
added to all wells and mixed thoroughly to dissolve the dark blue crystals.
The plates were read on SpectraMax 190 Microplate reader (Molecular De-
vices Inc., U.S.A.) at 570 nm within 1 h of DMSO addition. The experiment
General Procedure for Synthesis of Amides (16, 17, 20, 21) 120 mg
3,4,5-Trimethoxycinnamic acid 10 (1 mmol) was taken in 10 ml dry DMF.
To this, 106 mg EDC (1.1 mmol), 75 mg HOBt (1.1 mmol), and 1 ml triethy-
lamine were added and stirred at room temperature for 20 min. Later, 75 mg
3,4-methylenedioxyaniline (1.1 mmol) was added to the reaction mixture
and further stirred for 6 h. On completion, 10 ml water was added and ex-
tracted with chloroform (3ꢂ20 ml). The organic layer was washed with
water, dried over anhydrous Na2SO4, and evaporated in vacuo. The residue
thus obtained was purified through a silica gel column by eluting with
hexane–ethyl acetate. The desired amide 16 was obtained as a creamy white
solid.
(E)-N-(3,4-Methylenedioxyphenyl)-3-(3,4,5-trimethoxyphenyl)acrylamide
(16): Yieldꢃ46%. mpꢃ183—185 °C. 1H-NMR (CDCl3) d: 3.89 (s, 9H,