Synthesis and antiproliferative and c-Src kinase inhibitory activities of cinnamoyl-and pyranochromen-2-one derivatives

Article abstract of DOI:10.1139/cjc-2013-0053

A series of 6-and 8-cinnamoylchromen-2-one and dihydropyranochromen-2-one derivatives were synthesized and their antiproliferative activities were evaluated against three human cancer cell lines, i.e., ovarian adenocarcinoma (SK-OV-3), leukemia (CCRF-CEM), and breast carcinoma (MCF-7). In general, 8-cinnamoylchromen-2-one derivatives were found to have higher antiproliferative activity against the cancer cells when compared with 6-cinnamoyl analogues. Among all of the hybrid chromen-2-one-chalcone/flavanone compounds, a 7-hydroxy-8-cinnamoylchromen-2-one derivative 35 was found to be consistently active against all the cancer cell lines and inhibited the cell proliferation of SK-OV-3, CCRF-CEM, and MCF-7 by 63%, 50%, and 43%, respectively, at a concentration of 50 μmol/L after 72 h of incubation. This compound also exhibited the highest Src kinase inhibition (IC₅₀ = 14.5 μmol/L). Structure-activity relationship studies provided insights for designing the next generation of chromen-2-one-chalcone hybrid prototypes and the development of new leads as anticancer agents and (or) Src kinase inhibitors.

Full text of DOI:10.1139/cjc-2013-0053

Page 1 of 52
1
Synthesis, Antiproliferative and cꢀSrc kinase Inhibitory Activities of
Cinnamoylꢀ and Pyranochromenꢀ2ꢀone Derivatives
a
b
a
b
a
Karam Chand, Amir Nasrolahi Shirazi, Preeti Yadav, Rakesh K. Tiwari, Meena Kumari,
b,
a,
Keykavous Parang, * Sunil K. Sharma *
a
b
Department of Chemistry, University of Delhi, Delhi 110007, India; Department of
Biomedical and Pharmaceutical Sciences, College of Pharmacy, The University of Rhode
Island, Kingston, RI 02881, USA
sk.sharma90@gmail.com
kparang@uri.edu
TITLE RUNNING HEAD. Synthesis and evaluation of cinnamoyl- and pyranochromen-2-
one derivatives as antiproliferative and c-Src kinase inhibitory agents
*
Corresponding authors:
S. K. Sharma: Department of Chemistry, University of Delhi, Delhi 110 007, India; Phone:
91ꢀ11ꢀ27666646 Ext. 191; Fax: +91ꢀ11ꢀ27667206; Eꢀmail: sk.sharma90@gmail.com
+
K. Parang: 7 Greenhouse Road, Department of Biomedical and Pharmaceutical Sciences,
College of Pharmacy, University of Rhode Island, Kingston, Rhode Island, 02881, USA;
Tel.: +1ꢀ401ꢀ874ꢀ4471; Fax: +1ꢀ401ꢀ874ꢀ5787; Eꢀmail: kparang@uri.edu.

Page 2 of 52
2
Abstract. A series of 6ꢀ and 8ꢀcinnamoylchromenꢀ2ꢀone and dihydropyranochromenꢀ2ꢀone
derivatives, were synthesized, and their antiproliferative activities were evaluated against
three human cancer cell lines i.e., ovarian adenocarcinoma (SKꢀOVꢀ3), leukemia (CCRFꢀ
CEM), and breast carcinoma (MCFꢀ7). In general, 8ꢀcinnamoyl chromenꢀ2ꢀone derivatives
were found to have higher antiproliferative activity against the cancer cells when compared
with 6ꢀcinnamoyl analogues. Among all the hybrid chromenꢀ2ꢀone ꢀ chalcone/flavanone
compounds, a 7ꢀhydroxyꢀ8ꢀcinnamoyl chromenꢀ2ꢀone derivative 35 was found to be
consistently active against all the cancer cell lines and inhibited the cell proliferation of SKꢀ
OVꢀ3, CCRFꢀCEM, and MCFꢀ7 by 63%, 50% and 43%, respectively, at a concentration of
50 µM after 72 h incubation. This compound also exhibited the highest Src kinase inhibition
(IC50 = 14.5 ꢁM). Structureꢀactivity relationship studies provided insights for designing the
next generation of chromenꢀ2ꢀone ꢀ chalcone hybrid prototypes and the development of new
leads as anticancer agents and/or Src kinase inhibitors.
KEY WORDS: Anticancer; Antiproliferative; cꢀSrc kinase; Chromenꢀ2ꢀone

Page 3 of 52
3
Introduction
Although a lot of progress has been made in developing anticancer agents, cancer still
remains an enormous threat to people’s health in the 21st century. Antiproliferative drugs
have provided several advantages in cancer chemotherapy, such as increasing survival time in
cancer patients. However, these drugs cause toxicity because of nonꢀspecific targeting of
normal cells. Furthermore, multiꢀdrug resistance is one of the major challenges being
encountered in cancer chemotherapy. Thus, there is an urgent need to design novel alternative
1
,2
anticancer agents with higher therapeutic index.
3
A number of natural products have been known to exhibit anticancer activities. Natural
products were also able to demonstrate synergistic beneficial effects when used in
3
,4
combination with known chemotherapeutic drugs. In this perspective, chromenꢀ2ꢀones
(coumarins) and chalcones constitute important groups of natural products belonging to the
flavonoid family, and are known to possess antiproliferative activity against various cancer
cell lines. Their ease of synthesis, high stability, abundance in plants, and inherent biological
activities and physical properties have rekindled interest for the inꢀdepth study of their
5
,6
pharmaceutical and industrial applications. For example, (+)ꢀCalanolide A (1), a natural
7
dipyranochromenꢀ2ꢀone, is currently undergoing antiꢀAIDS clinical trials. Novobicin is an
aminochromenꢀ2ꢀone antibiotic that has been reported to inhibit DNA gyrase and to have
8,9
anticancer activity. Other compounds in this class include chromenꢀ2ꢀone analogue (3) of
+)ꢀdiscodermolide (2) (Fig. 1), that exhibits comparable antiproliferative activity against a
(
wide range of cancer cell lines, including breast carcinoma cells (MCFꢀ7) and ovarian
carcinoma cells (SKꢀOVꢀ3), as well as the multiꢀdrug resistant (MDR) cell line (NCI/ADR),
10
which overexpresses the MDR efflux pump, Pꢀglycoprotein.

Page 4 of 52
4
Furthermore, compounds with chalcone scaffold were found to be cancer preventive. These
1
1,12
compounds are available in the human diet, rich in fruits and vegetables.
They contain
two aromatic rings separated by an α,βꢀunsaturated ketone, that identified to be responsible
13ꢀ15
for various activities of these molecules.
Natural and synthetic chalcones have been
reported to possess high antiproliferative activity in primary and established ovarian
16
17
carcinoma and gastric cancer cells. Earlier reports have shown that chalcones having a
methoxyphenyl group exhibit potent biological activities against various cancer cell lines.
1
8
19
Recent representative examples are compounds 4 and 5 (Fig. 1). Compound 4 was
reported to be active against PaCaꢀ2 cell lines (IC50 = 0.03 µM), while the chalcone 5 is
active against Colonꢀ205 cells (IC50 = 2.2 µM).
OH
O
O
O
O
O
OH
HO
OH
O
O
OH
OH
NH2
NH2
O
HO
O
1
(+)ꢀCalanolide A
O
OMe
MeO
O
O
2
(+)ꢀDiscodermolide
3 Coumarin analog of (+)ꢀ2
R
OMe
MeO
MeO
MeO
O
N
N
4
5
R = 3ꢀindole
R = 3ꢀOMeꢀC H4
6
O
6
Figure 1.Structure of potent biological active chromenꢀ2ꢀone and chalcones against various
cancer cell lines.
Moreover, Ciupa et al. found that hybrid chalcone 6 displayed selective antiproliferative
activity against HTꢀ29 and MDAMBꢀ231 cell lines with IC50 values of 2.9 µM and 4.8 µM,
20
respectively. The remarkable biological potential of chalcones is due to their possible
2
1,22
interactions with various proteins related to cell apoptosis and proliferation.
Clinical trials

Page 5 of 52
5
and mechanistic studies have shown that although these compounds reach reasonable plasma
23
concentrations, they are not associated to remarkable toxicity and their derivatives are able
24,25
to cross the brain blood barrier.
Inclusion of two different biologically active pharmacophores into the same structure,
also known as ‘medicinal chemistry hybridization’, has been attempted previously in a
6,26ꢀ28
successful manner, and the results have been quite encouraging.
Bombardelli and
Valenti have synthesized chromenꢀ2ꢀone ꢀ chalcone hybrids, wherein, these hybrids have
2
9
shown significant tumor inhibition in taxolꢀresistant cancer cells. Sashidhara et al.
synthesized a series of compounds that contained chromenꢀ2ꢀone and chalcone skeleton in
one entity and evaluated them for in vitro cytotoxicity against a panel of four human cancer
cell lines and normal fibroblasts (NIH3T3). Some of these compounds showed promising
2
8
results with IC50 values of 3.6ꢀ8.1 µM. Valente et al. synthesized two classes of
benzoylvinyl chromenꢀ2ꢀones and cinnamoyl chromenꢀ2ꢀones with substitution at Cꢀ4
position of pyrone ring and evaluated them for Cdc25 phosphatases inhibitory activity. Initial
results indicated that benzoylvinyl chromenꢀ2ꢀones showed a higher Cdc25 phosphatases
5
inhibitory activity than cinnamoyl chromenꢀ2ꢀones. In another report, a series of Cꢀ3
substituted chromenꢀ2ꢀone based chalcones were found to exhibit significant antibacterial and
6
DPPH radical scavenging activities. Furthermore, bischromenꢀ2ꢀoneꢀchalcone hybrids were
2
7
found to exhibit interesting antiꢀinflammatory and antioxidant activities.
To explore the chemical diversity space around chromenꢀ2ꢀone and chalcone scaffolds,
we synthesized various derivatives by combining chromenꢀ2ꢀone and chalcone
pharmacophores in one unit, and evaluated them for antiproliferative activities towards
human ovarian adenocarcinoma (SKꢀOVꢀ3), leukemia (CCRFꢀCEM), breast carcinoma
3
0
(
MCFꢀ7) cells, and for Src kinase inhibitory activity. Although both benzovinyl and

Page 6 of 52
6
5,6,29
cinnamoyl chromenꢀ2ꢀones have been previously synthesized
, most of these conjugates
were formed through the Cꢀ3/Cꢀ4 position of chromenꢀ2ꢀone. Herein, we have explored the
structureꢀactivity relationship in the hybrid compounds possessing the chromenꢀ2ꢀone
(coumarin skeleton) and 1,3ꢀdiarylꢀα,βꢀunsaturated ketone (chalcone skeleton), wherein the
cinnamoyl moiety is linked through Cꢀ6 and Cꢀ8 of 7ꢀhydroxyꢀ4ꢀmethylchromenꢀ2ꢀone.
Moreover, the development of cꢀSrc kinase inhibitors is another area of interest in
anticancer drug design. Overꢀexpression and amplification of Src kinase have been shown to
be associated with many forms of human epithelial tumors, such as ovary, colon, lung and
31
breast cancers. Src kinase is a key modulator of cancer cell invasion and metastasis activity.
Discovering new compounds with high Src kinase inhibitory potency is a subject of major
3
2
interest in designing anticancer drugs. The Src kinase inhibition activity of all the
compounds were also studied. Herein, we report the synthesis and evaluation of
antiproliferative and Src kinase inhibitory activities of novel cinnamoyl chromenꢀ2ꢀone
derivatives.
Results and discussion
Chemistry
The synthesis of chromenꢀ2ꢀone (coumarin) skeleton has been developed via Pechmann
33ꢀ35
condensation in addition to other methods available in the literature.
The α,βꢀunsaturated
carbonyl moiety can readily be incorporated by the baseꢀcatalyzed Claisen Schmidt
condensation of an aldehyde and ketone having active methylene group in a polar solvent like
36,37
ethanol or methanol.

Page 7 of 52
7
Synthesis of 6/8ꢀacetylꢀ3ꢀalkylꢀ7ꢀhydroxyꢀ4ꢀmethylchromenꢀ2ꢀones (12ꢀ15)
First, synthesis of 7ꢀhydroxyꢀ3ꢀalkylꢀ4ꢀmethylchromenꢀ2ꢀones (10 and 11) was carried
out by reacting βꢀresorcinol with alkylated ethyl acetoacetate using Pechmann condensation.
The obtained crude products were then acetylated with acetic anhydride in the presence of a
catalytic amount of dimethylaminopyridine (DMAP) in THF to yield the corresponding 7ꢀ
acetoxyꢀ3ꢀalkylꢀ4ꢀmethylchromenꢀ2ꢀone derivatives. The Cꢀ8 acetyl (12 and 14) and Cꢀ6
acetyl (13 and 15) derivatives of chromenꢀ2ꢀone (Scheme 1) were then obtained from 7ꢀ
3
8,39
acetoxyꢀ3ꢀalkylꢀ4ꢀmethylchromenꢀ2ꢀones via Fries migration in the 9:1 ratio.
Scheme 1. Synthesis of 6/8ꢀacetyl chromenꢀ2ꢀones. Reagents and conditions: i. Conc. H SO ,
2
4
o
3 2 3
RT; ii. (CH CO) O, DMAP, THF, RT; iii. AlCl , 125ꢀ170 C.
Since the yield of 6ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylchromenꢀ2ꢀone (13) was not satisfactory
via Fries migration, this compound was synthesized by an alternative method in 60% yield
by reacting 2,4ꢀdihydroxyacetophenone with ethyl acetoacetate in the presence of silica and
40
perchloric acid (Scheme 2).

Page 8 of 52
8
Scheme 2. Synthesis of 6ꢀacetyl chromenꢀ2ꢀones. Reagents and conditions: i. HClO .SiO ;
4
2
o
1
30 C; solventꢀfree, 30ꢀ90 min.
Synthesis of chromenꢀ2ꢀone ꢀ chalcone/flavanone hybrids.
The synthesis of cinnamoyl chromenꢀ2ꢀone derivatives (17ꢀ45 and 48ꢀ56) was carried out
through Claisen Schmidt condensation by reacting 6ꢀ/8ꢀacetyl chromenꢀ2ꢀones with
various aldehydes in the presence of piperidine in absolute ethanol (Schemes 3 and 4).
Scheme 3. Synthesis of 8ꢀcinnamoylꢀ and dihydropyranochromenꢀ2ꢀone derivatives.
Reagents and conditions: i. piperidine, abs. ethanol, reflux 6ꢀ8 h.

Page 9 of 52
9
Chalcones containing a hydroxyl group orthoꢀ to carbonyl (ring A) are known to
cyclize under strong alkaline conditions to the corresponding flavanones. To avoid such
intramolecular cyclization, we have used a weaker base piperidine for Claisen Schmidt
condensation. This method not only minimizes the formation of side products, such as
multiple condensation, polymerizations and rearranged products, but also simplifies the
purification process and enhances the overall yield. However, even by using piperidine, the
formation of cyclic products was observed in a few cases. The formation of
dihydropyranochromenꢀ2ꢀones 46ꢀ47 and 59ꢀ61 was observed due to the cyclization of
corresponding cinnamoyl chromenꢀ2ꢀones. All the products were fully characterized from
their physical and spectral data and subjected to antiproliferative activity screening.
Scheme 4. Synthesis of 6ꢀcinnamoylꢀ and dihydropyranochromenꢀ2ꢀone derivatives.
Reagents and conditions: i. piperidine, abs. ethanol, reflux 6ꢀ8 hrs.

Page 10 of 52
1
0
Antiproliferative activities
series of forty five diverse substituted cinnamoylchromenꢀ2ꢀone and
A
dihydropyranochromenꢀ2ꢀone derivatives (17ꢀ61) and their precursors (12ꢀ15) were evaluated
against three human carcinoma cell lines namely human leukemia cell line CCRFꢀCEM,
breast adenocarcinoma MCFꢀ7, and ovarian adenocarcinoma SKꢀOVꢀ3 at the concentration
of 50 ꢁM.
Analysis of cell proliferation activity (Figs. 2 and 3) revealed that compounds 14, 17ꢀ22, 27,
33, 36, 38ꢀ40, 45ꢀ47, 49, 54ꢀ56, and 60 exhibited higher antiproliferative activity against
CCRFꢀCEM cell line compared to SKꢀOVꢀ3 and MCFꢀ7 cells. Fifteen compounds i.e. 18ꢀ21,
27, 33ꢀ36, 38, 39, 45, 47, 55, and 60 demonstrated modest antiproliferative activities (34ꢀ
66%) against CCRFꢀCEM cell lines. However, only four compounds 23, 24, 35, and 43 were
found to exhibit antiproliferative activities (26ꢀ63% inhibition) against SKꢀOVꢀ3, and five
compounds i.e. 21, 27, 33, 35, and 55 exhibited moderate activity in the range of 40ꢀ43%
against MCFꢀ7 (Figs. 2 and 3).
Among all the compounds, 35 was found to be active against all the cell lines and inhibited
the cell proliferation of SKꢀOVꢀ3 (63%), CCRFꢀCEM (50%), and MCFꢀ7 (43%) (Fig.2).
Furthermore, compounds 21 (41% and 61%), 27 (43% and 51%), 33 (40% and 44%), and 55
(39% and 45%) were found to be moderately active against two cell lines i.e. MCFꢀ7 and
CCRFꢀCEM. In general, 8ꢀcinnamoyl chromenꢀ2ꢀone derivatives (17ꢀ45) were found to
possess improved antiproliferative activity against the cell lines studied when compared with
6ꢀcinnamoylchromenꢀ2ꢀone derivatives (49ꢀ58). Among all 6ꢀcinnamoyl derivatives (48ꢀ58),
only one compound (55) was found to be moderately active against MCFꢀ7 and CCRFꢀCEM
cells.

Page 11 of 52
1
1
Figure 2. Inhibition of SKꢀOVꢀ3, CCRFꢀCEM, and MCFꢀ7 cells by compounds 12ꢀ36 (50
M) after 72 h incubation. The results are shown as the percentage of the control that has no
ꢁ
compound (set at 100 %). All the experiments were performed in triplicate.
Figure 3. Inhibition of SKꢀOVꢀ3, CCRFꢀCEM, and MCFꢀ7 cells by compounds 37ꢀ61 (50
ꢁM) after 72 h incubation. The results are shown as the percentage of the control that has no
compound (set at 100 %). All the experiments were performed in triplicate.

Page 12 of 52
1
2
Structureꢀactivity relationship (SAR) indicates that disubstitution on the phenyl group of the
cinnamoyl moiety enhances antiproliferative activity. Amongst the fifteen disubstituted
cinnamoyl chromenꢀ2ꢀones (27ꢀ38, and 53ꢀ55), seven showed activity against at least one cell
line, four compounds showed activity against at least two cell lines, and one compound (35)
was observed to be active against all the three cell lines studied. Closely analyzing
antiproliferative results showed that 3,4ꢀdisubstituted 8ꢀcinnamoyl chromenꢀ2ꢀones have
modest antiproliferative activity, while other disubstituted analogs, such as the 2,4ꢀ and 2,5ꢀ
disubstituted cinnamoylchromenꢀ2ꢀones, were found to have minimal antiproliferative
activity. However, one 2,3ꢀdisubstituted analog (27) inhibited MCFꢀ7 and CCRFꢀCEM cells
by 43 and 51%.
On the other hand, of the twelve monosubstituted cinnamoylchromenꢀ2ꢀone derivatives (19ꢀ
2
6, and 49ꢀ52), five compounds exhibited antiproliferative activity against at least one cell
line. For example, compounds 19ꢀ22 showed a moderate activity against CCRFꢀCEM (33ꢀ
1%) while compound 24 exhibited antiproliferative activity against SKꢀOVꢀ3 cells (43%).
6
All the modestly active compounds were found to be 8ꢀcinnamoylchromenꢀ2ꢀone derivatives.
Trisubstituted cinnamoyl chromenꢀ2ꢀones were found to show weak antiproliferative activity,
as of the nine such compounds (39ꢀ44, and 56ꢀ58) only two 8ꢀcinnamoyl chromenꢀ2ꢀones i.e.
compounds 39 and 43 inhibited the proliferation of CCRFꢀCEM and SKꢀOVꢀ3 by 39% and
38%, respectively. Results showed that the presence of an alkyl substituent at Cꢀ3 position of
chromenꢀ2ꢀone moiety has no role in improving inhibition potency.
Src kinase inhibitory activity
The Src kinase inhibitory activities of all the cinnamoylchromenꢀ2ꢀone and
dihydropyranochromenꢀ2ꢀone derivatives were evaluated. Furthermore, the data were used to

Page 13 of 52
1
3
determine whether there is any correlation between antiproliferative activity and Src kinase
inhibition. Table 1 shows the kinase inhibition results in comparison to a standard protein
kinase inhibitor, staurosporine.
Table 1. Src kinase inhibitory activity of cinnamoylꢀ and dihydropyrano chromenꢀ2ꢀone
derivatives (12ꢀ61).
a
a
Compound
IC (ꢁM)
Compound
IC (ꢁM)
5
0
50
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
>100
>250
>250
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
67.0
>100
>250
>100
>100
>100
>100
>100
26.3
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
75.0
>100
22.1
>100
>100
>100
33.0
>100
>100
42.2
>100
43.0
27.5
25.0
75
>250
75.0
>250
28.2
42.3
26.7
39.6
>250
>250
29.9
>100
14.5
>250
0.25
Staurosporine
a
The concentration at which the enzyme activity is inhibited by 50%. IC50 value is calculated
from Graph Prism software. All the experiments were carried out in triplicate.

Page 14 of 52
1
4
In general, out of forty nine compounds screened, only thirteen compounds i.e. 33, 35,
9, 43, 46, 48, 49, 50, 55ꢀ58, and 61 were found to exhibit Src kinase inhibitory activity with
3
IC50 value of 14.5ꢀ43.0 ꢁM. SAR study indicates that out of these thirteen compounds, four
have cinnamoyl moiety at Cꢀ8 position (33, 35, 39, and 43) while seven are 6ꢀcinnamoyl
chromenꢀ2ꢀones (48ꢀ50 and 55ꢀ58), thus suggesting that the presence of cinnamoyl moiety at
Cꢀ6 of chromenꢀ2ꢀone is more favorable for Src kinase inhibition. None of the compounds
with an ethyl group at Cꢀ3 position was found to possess noticeable Src kinase inhibition
properties. However, among the dihydropyranochromenꢀ2ꢀone derivatives, two compounds
i.e. 46 and 61 showed modest Src kinase inhibitory activity (IC50 = 29.9ꢀ42.2 µM).
Compound 35, which was found to exhibit the most promising antiproliferative activity
41
against the three cancer cell lines including SKꢀOVꢀ3 that over expresses cꢀSrc, also
exhibited the highest Src kinase inhibition (IC50 = 14.5 ꢁM). The analogs of this compound
may be investigated for further optimization for generation of lead anticancer agents with Src
kinase inhibitory activities. Compounds 33, 39, 49, 50, 55, and 57 also showed modest Src
kinase inhibition (IC50 = 22.1ꢀ28.2 µM).
Conclusions
A series of forty five chromenꢀ2ꢀone based chalcone derivatives and their four precursors
were synthesized and evaluated for their anticancer activity against a panel of three human
cancer cell lines and Src kinase inhibitory potency. The structures of the compounds were
1
13
confirmed by H NMR, C NMR, HRMS, UV, and FTꢀIR. Among the compounds reported
here, thirty five are novel i.e. compounds 18ꢀ20, 22, 24, 26ꢀ32, 34ꢀ36, 38ꢀ45, 47ꢀ49, and 53ꢀ
61. Although compounds 14ꢀ15, 21, 23, 25, 33, 37, 46, 50, and 51ꢀ52 were previously

Page 15 of 52
1
5
reported in the literature, however, their complete spectral data were not reported. Herein, we
have provided the spectral data for all the compounds in the experimental section.
Antiproliferative assay results showed that 8ꢀcinnamoyl chromenꢀ2ꢀone derivatives had
higher antiproliferative activity against the studied cancer cell lines (CCRFꢀCEM, MCFꢀ7,
and SKꢀOVꢀ3) than 6ꢀcinnamoyl chromenꢀ2ꢀone conjugates. Compound 35 showed 40ꢀ63%
antiproliferative activity in all three cancer cell lines and exhibited Src kinase inhibitory
activity with an IC50 value of 14.5 ꢁM. Compounds 21, 27, 33 and 55 also exhibited modest
inhibition effect (39ꢀ61%) in MCFꢀ7 and CCRFꢀCEM cells. Among these compounds, 33
and 55 also showed modest Src kinase inhibition (IC50 = 26.3ꢀ28.2 µM). In conclusion,
incorporation of α,βꢀunsaturated ketone moiety on a chromenꢀ2ꢀone scaffold was found to be
a moderately effective strategy to enhance the antiproliferative activity and Srcꢀkinase
inhibitory potential. Precursors of these chromenꢀ2ꢀone based chalcone derivatives did not
show any significant inhibition of cell proliferation in any of the cancer cell lines and Src
kinase. Structureꢀactivity relationship studies provided insights for designing the next
generation of chromenꢀ2ꢀone ꢀ chalcone hybrid prototypes and development of new lead
compounds as anticancer agents and/or Src kinase inhibitors.
Experimental
Materials and methods
The organic solvents were dried and distilled prior to their use. Reactions were monitored by
precoated TLC plates (Merck silica gel 60 F254); the spots were visualized either by UV light,
3
or by spraying with 5% alcoholic FeCl solution. Silica gel (100ꢀ200 mesh) was used for
column chromatography. All the chemicals and reagents were procured from Spectrochem
Pvt. Ltd., India and SigmaꢀAldrich Chemicals Pvt. Ltd., USA. Melting points were measured

Page 16 of 52
1
6
on Buchi Mꢀ560 apparatus and are uncorrected. Infrared spectra were recorded on Perkinꢀ
1
13
Elmer FTꢀIR model 9 spectrophotometer. The H and C NMR spectra were recorded on
Jeolꢀ400 (400 MHz, 100.5 MHz) NMR spectrometer and Avanceꢀ300 (300 MHz, 75.5 MHz)
spectrometer using TMS as internal standard. The chemical shift values are on δ scale and the
coupling constant values (J) are in Hz. The HRMS data were recorded on Agilentꢀ6210 ESꢀ
TOF, JEOL JMXꢀSXꢀ102A and Waters LCT MicromassꢀKC455.
General procedure for synthesis of 8/6ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀones
(12ꢀ15). 7ꢀAcetoxyꢀ3ꢀalkylꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (9.2 mmol) and anhydrous
aluminium chloride (34 mmol) were taken in a round bottom flask fitted with a reflux
o
condenser. The temperature of the reaction mixture was raised quickly to 125 C and then
o
slowly over a period of 2 h to 170 C. Then, crushed ice was added to the reaction mixture
followed by the acidification using dilute hydrochloric acid. The crude product was filtered,
washed with water followed by ether and then subjected to column chromatography
(petroleum ether/ethyl acetate).
8ꢀAcetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (12). Compound 12 was obtained as light
yellow solid in 70% yield by column chromatography using ethyl acetateꢀpetroleum ether
o
o
36,37
(
(
(
1:20 v/v) as an eluent; Melting point: 162ꢀ163 C (Literature mp = 162ꢀ163 C)
Acetonitrile) λmax: 211, 308 and 350 nm; IR (Nujol) νmax: 2920.95, 2853.95, 1738.43
COCH ), 1732.03 (CO), 1610.85, 1463.28, 1371.81, 1234.08, 1087.60, 1059.53, 878.03,
58.62 cm ; H NMR (CDCl
.08 (s, 1H, Hꢀ3), 6.82 (d, 1H, J = 8.8 Hz, Hꢀ6), 7.60 (d, 1H, J = 8.8 Hz, Hꢀ5), 13.48 (brs,
; UV
3
ꢀ
1 1
6
6
1
1
3 3 3
, 400 MHz): δ 2.36 (s, 3H, Cꢀ4 CH ), 2.86 (s, 3H, ꢀCOCH ),
1
3
H, OH); C NMR (CDCl
3 3 3
, 100.5 MHz): δ 19.08 (Cꢀ4 CH ), 33.79 (ꢀCOCH ), 109.09 (Cꢀ8),
10.89, 111.73 and 114.96 (Cꢀ3, Cꢀ6 and Cꢀ10), 131.19 (Cꢀ5), 152.95 (Cꢀ9), 154.98 (Cꢀ4),

Page 17 of 52
1
7
+.
1
59.19 (Cꢀ7), 166.47 (Cꢀ2), 204.21 (COCH
3 10 4
). ESI MS: Calculated for C12H O [M] 218,
found 218.
6ꢀAcetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (13). Compound 13 was obtained as light
yellow solid in 70% yield by column chromatography using ethyl acetate/petroleum ether
o
o
36,37
(
(
(
1:10 v/v) as an eluent. Melting point: 210ꢀ211 C (Literature value = 211 C)
; UV
Acetonitrile) λmax: 257, 297 and 342 nm; IR (KBr) νmax: 3438.76 (OH), 2357.39, 1738.11
ꢀ1 1
3
CO), 1614.66, 1369.57, 1308.01, 1233.59, 1059.21, 876.65, 657.39 cm ; H NMR (CDCl ,
400 MHz): δ 2.42 (s, 3H, Cꢀ4 CH
3 3
), 2.68 (s, 3H, ꢀCOCH ), 6.15 (s, 1H, Hꢀ3), 6.82 (s, 1H, Hꢀ
13
8
), 7.94 (s, 1H, Hꢀ5), 12.61 (brs, 1H, OH); C NMR (CDCl , 100.5 MHz): δ 18.57 (Cꢀ4
3
3 3
CH ), 26.63 (ꢀCOCH ), 105.39 (Cꢀ8), 112.86 and 112.99 (Cꢀ3 and Cꢀ10), 117.07 (Cꢀ6),
3
128.12 (Cꢀ5), 151.62 (Cꢀ4), 158.71 (Cꢀ9), 159.88 (Cꢀ7), 165.31 (Cꢀ2), 203.30 (ꢀCOCH ); ESI
+
MS: Calculated for C12
H
10
O
4
[M + H] 219, found 219.
8ꢀAcetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (14). Compound 14 was
obtained as light yellow solid in 70% yield by column chromatography using ethyl
o
acetate/petroleum ether (1:10 v/v) as an eluent. Melting point: 171ꢀ172 C; UV (Acetonitrile)
λ
max: 240, 273, 305 and 350 nm; IR (KBr) νmax: 2970.32, 2935.77, 1717.83 (CO), 1614.92,
ꢀ1 1
1
370.28, 1215.39, 1092.50, 834.73, 647.36 cm ; H NMR (CDCl
3
, 400 MHz): δ 1.09 (t, 3H,
J = 7.3 Hz, ꢀCH
2
CH ), 2.33 (s, 3H, Cꢀ4 CH ), 2.59 (q, 2H, J = 7.3 Hz, ꢀCH
3
3
2
CH ), 2.86 (s, 3H,
3
ꢀ
COCH ), 6.78 (d, 1H, J = 8.7 Hz, Hꢀ6), 7.60 (d, 1H, J = 9.5 Hz, Hꢀ5), 13.34 (brs, 1H, OH);
3
1
3
3 2 3 3 2 3
C NMR (CDCl , 100.5 MHz): δ 12.90 (ꢀCH CH ), 14.77 (Cꢀ4 CH ), 20.57 (ꢀCH CH ),
3
33.82 (ꢀCOCH ), 108.88 (Cꢀ8), 112.46 and 114.62 (Cꢀ6 and Cꢀ10), 124.14 (Cꢀ3), 131.23 (Cꢀ
3
5), 146.03 (Cꢀ4), 153.32 (Cꢀ9), 160.07 (Cꢀ7), 165.34 (Cꢀ2), 204.24 (ꢀCOCH ); HRMS:
+
Calculated for C14
H
14
O
4
[M + H] 247.0926, found 247.0965.

Page 18 of 52
1
8
6ꢀAcetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (15). Compound 15 was
obtained as light yellow solid in 70% yield by column chromatography using ethyl
o
acetate/petroleum ether (1:20 v/v) as an eluent. Melting point: 144ꢀ146 C; UV (Acetonitrile)
λmax: 210, 230, 256, 305 and 341 nm; IR (KBr) νmax: 3413.02 (OH), 3057.27, 2973.31,
ꢀ
1 1
1
721.02 (CO), 1646.41, 1386.40, 1254.88, 1167.11, 1058.49, 930.50, 805.41 cm ; H NMR
CDCl , 400 MHz): δ 1.10 (t, 3H, J = 7.3 Hz, ꢀCH CH ), 2.38 (s, 3H, Cꢀ4 CH ), 2.61 (q, 2H,
J = 7.3 Hz, ꢀCH CH ), 2.67 (s, 3H, ꢀCOCH ), 6.74 (s, 1H, Hꢀ8), 7.91 (s, 1H, Hꢀ5), 12.50 (brs,
H, OH); C NMR (CDCl , 100.5 MHz): δ 13.03 (ꢀCH CH ), 14.77 (Cꢀ4 CH ), 20.86 (ꢀ
CH CH ), 26.57 (ꢀCOCH ), 104.72 (Cꢀ8), 113.52 and 116.92 (Cꢀ6 and Cꢀ10), 125.99 (Cꢀ3),
(
3
2
3
3
2
3
3
13
1
3
2
3
3
2
3
3
127.88 (Cꢀ5), 144.75 (Cꢀ4), 157.27 (Cꢀ9), 160.65 (Cꢀ7), 164.16 (Cꢀ2), 203.38 (ꢀCOCH3);
+
HRMS: Calculated for C14
H
14
O
4
[M + Na] 269.0790, found 269.0784.
General procedure for the synthesis of chromenꢀ2ꢀoneꢀchalcone/flavanone hybrids (17ꢀ
1). A mixture of 8ꢀacetylꢀ3ꢀalkylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone or 6ꢀacetylꢀ7ꢀ
hydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (0.01 mole) and an appropriate aromatic aldehyde
0.012 mole) in absolute ethanol (50ꢀ55 ml) was refluxed with piperidine (1ꢀ2 drops) for 6ꢀ8
6
(
hrs (Scheme 2). On concentrating the reaction mixture to a small volume, chalcone/flavanone
separated out which was filtered and purified by either column chromatography or
crystallized from methanolꢀmethylene chloride.
7ꢀHydroxyꢀ4ꢀmethylꢀ8ꢀ[(2E,4E)ꢀ5ꢀphenylpentaꢀ2,4ꢀdienoyl]ꢀ2Hꢀchromenꢀ2ꢀone
(17).
Compound (17) was obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀ
chromenꢀ2ꢀone (12) with cinnamaldehyde as a light yellow solid in 79% yield by column
chromatography using ethyl acetate/petroleum ether (1:10 v/v) as an eluent. Melting point:
o
1
2
7
84ꢀ186 C; UV (Chloroform) λmax: 325.58 and 377.67 nm; IR (KBr) νmax : 3439.77 (OH),
925.24, 1733.87, (OCO), 1604.25, 1545.40, 1390.11, 1230.96, 1082.33, 998.60, 849.98,
ꢀ1 1
3 3
49.62, 686.15 cm ; H NMR (CDCl , 400 MHz): δ 2.31 (s, 3H, Cꢀ4 CH ), 6.06 (s, 1H, Hꢀ

Page 19 of 52
1
9
3), 6.82 (d, 1H, J = 8.8 Hz, Hꢀ6), 6.94ꢀ7.08 (m, 2H, H ꢀ4' and H ꢀ5'), 7.20ꢀ7.29 (m, 3H, Hꢀ3",
Hꢀ4" and Hꢀ5"), 7.42ꢀ7.43 (m, 2H, Hꢀ2" and Hꢀ6"), 7.54 (d, 1H, J = 8.8 Hz, Hꢀ5), 7.65 (d,
13
1
H, J = 14.6 Hz, Hꢀ2') 7.70 (d, 1H, J = 14.6 Hz, Hꢀ3'), 13.80 (brs, 1H, OH); C NMR
(
CDCl , 100.5 MHz): δ 19.31 (Cꢀ4 CH ), 109.69 (Cꢀ8 or Cꢀ10), 111.03 (Cꢀ3), 111.98 (Cꢀ8 or
3
3
Cꢀ10), 115.26 (Cꢀ6), 127.33 (Cꢀ3'), 127.62 (Cꢀ2" and Cꢀ6"), 128.85 (Cꢀ3" and Cꢀ5"), 129.26,
129.53 (Cꢀ4" and Cꢀ5'), 130.86 (Cꢀ5), 135.94 (Cꢀ1"), 143.46, 146.69 (Cꢀ2' and Cꢀ4'), 153.19,
154.68, 159.58 (Cꢀ4, Cꢀ7 and Cꢀ9), 167.29 (Cꢀ2), 193.04 (Cꢀ1'); HRMS: Calculated for
+
C
21
H
16
O
4
[M ꢀ H] 331.1049, found 331.2063.
3ꢀEthylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ8ꢀ[(2E,4E)ꢀ5ꢀphenylpentaꢀ2,4ꢀdienoyl]ꢀ2Hꢀchromenꢀ2ꢀone
(18). Compound (18) was obtained from the reaction of 8ꢀacetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀ
methylꢀ2Hꢀchromenꢀ2ꢀone (14) with cinnamaldehyde as a light yellow solid in 76% yield by
column chromatography using ethyl acetate/petroleum ether (1:20 v/v) as an eluent. Melting
o
point: 149ꢀ152 C; UV (Chloroform) λmax: 323.08 and 376.38 nm; IR (Nujol) νmax: 3422.96
(OH), 2926.99, 1727.92 (OCO), 1629.30 (CO), 1598.99, 1541.61, 1364.30, 1249.83,
ꢀ
1
1
1
085.77, 926.58, 768.83 cm ; H NMR (CDCl
CH ), 2.41 (s, 3H, Cꢀ4 CH ), 2.68ꢀ2.70 (m, 2H, CH
.05ꢀ7.20 (m, 2H, Hꢀ4' and Hꢀ5'), 7.36ꢀ7.38 (m, 3H, Hꢀ3", Hꢀ4" and Hꢀ5"), 7.53ꢀ7.55 (m, 2H,
Hꢀ2" and Hꢀ6"), 7.68 (d, 1H, J = 8.7 Hz, Hꢀ5), 7.79ꢀ7.80 (m, 2H, Hꢀ2' and Hꢀ3'), 13.76 (brs,
3
, 300 MHz): δ 1.17 (t, 3H, J = 7.2 Hz,
CH
2
3
3
2
CH ), 6.92 (d, 1H, J = 8.7 Hz, Hꢀ6),
3
7
1
3
1
H, OH); C NMR (CDCl , 75.5 MHz): δ 13.10 (CH CH ), 14.99 (Cꢀ4 CH ), 20.77
3 2 3 3
(CH
2 3
CH ), 109.49, 112.72 (Cꢀ8 and Cꢀ10), 114.96 (Cꢀ6), 124.24 (Cꢀ3), 127.45 (Cꢀ3'), 127.61
(Cꢀ2" and Cꢀ6"), 128.87 (Cꢀ3" and Cꢀ5"), 129.48, 129.52 (Cꢀ4" and Cꢀ5'), 130.99 (Cꢀ5),
136.03 (Cꢀ1"), 143.19, 146.35 (Cꢀ2', Cꢀ4' and Cꢀ4), 153.03, 160.46 (Cꢀ7 and Cꢀ9), 166.15 (Cꢀ
+
2), 193.12 (Cꢀ1'); HRMS: Calculated for C23
H
20
O
4
[M + Na] 383.1259, found 383.1258.
(E)ꢀ7ꢀHydroxyꢀ8ꢀ[3ꢀ(2ꢀmethoxyphenyl)acryloyl]ꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone
(19).
Compound (19) was obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀ

Page 20 of 52
2
0
chromenꢀ2ꢀone (12) with 2ꢀmethoxybenzaldehyde as a light yellow solid in 72% yield by
column chromatography using ethyl acetate/petroleum ether (1:10 v/v) as an eluent. Melting
o
point: 137ꢀ139 C; UV (Chloroform) λmax: 311.23 and 380.98 nm; IR (KBr) νmax : 3439.77
(OH), 3064.42, 2922.45, 1738.83 (OCO), 1597.97, 1487.56, 1388.43, 1241.96, 1181.23,
ꢀ
1 1
1
3
1
8
079.68, 877.80, 755.99 cm ; H NMR (CDCl , 400 MHz): δ 2.42 (s, 3H, Cꢀ4 CH ), 3.98 (s,
3
3
H, OCH
3
), 6.16 (s, 1H, Hꢀ3), 6.91ꢀ6.96 (m, 2H, Hꢀ3" and Hꢀ6), 7.03 (m, 1H, Hꢀ5"), 7.39 (m,
H, Hꢀ4"), 7.65 (d, 1H, J = 8.8 Hz, Hꢀ5), 7.71 (m, 1H, Hꢀ6"), 8.27 (d, 1H, J = 15.4 Hz, Hꢀ2'),
1
3
.41 (d, 1H, J = 15.4 Hz, Hꢀ3'), 14.03 (brs, 1H, OH); C NMR (CDCl
3
, 100.5 MHz): δ 19.26
(
Cꢀ4 CH ), 55.56 (OCH ), 109.75 (Cꢀ8 or Cꢀ10), 110.95, 111.11 (Cꢀ3" and Cꢀ3), 111.95 (Cꢀ8
3
3
or Cꢀ10), 115.20 (Cꢀ6), 120.87 (Cꢀ4"), 123.63 (Cꢀ1"), 126.53 (Cꢀ3'), 130.75, 130.82, 132.38
(Cꢀ5, Cꢀ5" and Cꢀ6"), 142.14 (Cꢀ2'), 153.13, 154.80 (Cꢀ4, Cꢀ9), 159.40 (Cꢀ2" and Cꢀ7),
+
1
67.37 (Cꢀ2), 193.75 (Cꢀ1'); HRMS: Calculated for C20
35.1961.
H
16
O
5
[M ꢀ H] 335.0998, found
3
(
E)ꢀ3ꢀEthylꢀ7ꢀhydroxyꢀ8ꢀ[3ꢀ(2ꢀmethoxyphenyl)acryloyl]ꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone
20). Compound (20) was obtained from the reaction of 8ꢀacetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀ
(
methylꢀ2Hꢀchromenꢀ2ꢀone (14) with 2ꢀmethoxybenzaldehyde as a light yellow solid in 73%
yield by column chromatography using ethyl acetate/petroleum ether (1:15 v/v) as an eluent.
o
Melting point: 167ꢀ169 C; UV (Chloroform) λmax: 310.76 and 382.89 nm; IR (KBr) νmax
:
3421.59 (OH), 2935.53, 1721.04 (OCO), 1626.62 (CO), 1615.62, 1592.54, 1358.62, 1265.81,
ꢀ1
1
1
183.97, 1085.87, 750.24 cm ; H NMR (CDCl
3
, 300 MHz): δ 1.18 (t, 3H, J = 7.5 Hz,
CH
2
CH ), 2.42 (s, 3H, Cꢀ4 CH ), 2.70 (q, 2H, J = 7.5 Hz, CH CH ), 3.99 (s, 3H, OCH ),
3
3 2 3 3
6
.92ꢀ6.98 (m, 2H, Hꢀ3" and Hꢀ6), 7.03 (m, 1H, Hꢀ5"), 7.40 (m, 1H, Hꢀ4"), 7.69 (d, 1H, J =
.0 Hz, Hꢀ5), 7.77 (dd, 1H, J = 1.5 and 7.5 Hz, Hꢀ6"), 8.30 (d, 1H, J = 15.6 Hz, Hꢀ2'), 8.47
9
13
(
d, 1H, J = 15.6 Hz, Hꢀ3'), 13.94 (brs, 1H, OH); C NMR (CDCl , 75.5 MHz): δ 13.05
3
2 3 3 2 3 3
(CH CH ), 14.91 (Cꢀ4 CH ), 20.72 (CH CH ), 55.56 (OCH ), 109.53 (Cꢀ8 or Cꢀ10), 111.08

Page 21 of 52
2
1
(Cꢀ3"), 112.65 (Cꢀ8 or Cꢀ10), 114.92 (Cꢀ6), 120.88 (Cꢀ4"), 123.76, 124.08 (Cꢀ1" and Cꢀ3),
126.67 (Cꢀ3'), 130.50, 130.91, 132.25 (Cꢀ5, Cꢀ5" and Cꢀ6"), 141.80 (Cꢀ2'), 146.30, 153.17,
159.32, 160.33 (Cꢀ2", Cꢀ4, Cꢀ7 and Cꢀ9), 166.32 (Cꢀ2), 193.86 (Cꢀ1'); HRMS: Calculated for
+
C
22
H
20
O
5
[M ꢀ H] 363.1311, found 363.2253.
(E)ꢀ7ꢀHydroxyꢀ4ꢀmethylꢀ8ꢀ(3ꢀpꢀtolylacryloyl)ꢀ2Hꢀchromenꢀ2ꢀone (21). Compound 21 was
obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (12) with 4ꢀ
methylbenzaldehyde as yellow solid in 72% yield by column chromatography using ethyl
o
acetate/petroleum ether (1:10 v/v) as an eluent. Melting point: 155ꢀ157 C; UV (Chloroform)
λmax: 242.33, 320.93 and 355.35 nm; IR (KBr) νmax: 3445.37 (OH), 2921.45, 1740.41 (OCO),
ꢀ1
1
633.60 (CO), 1598.46, 1543.27, 1385.80, 1188.20, 1079.47, 977.95, 829.67, 730.04 cm ;
1
H NMR (CDCl
3 3
, 400 MHz): δ 2.39, 2.42 (2s, 6H, Cꢀ4 and Cꢀ4" CH ), 6.17 (s, 1H, Hꢀ3),
6.93 (d, 1H, J = 9.2 Hz, Hꢀ6), 7.23 (d, 2H, 1H, J = 8.2 Hz, Hꢀ3" and Hꢀ5"), 7.61ꢀ7.67 (m, 3H,
1
3
Hꢀ2", Hꢀ5 and Hꢀ6"), 7.95 (d, 1H, J = 15.6 Hz, Hꢀ2'), 8.21 (d, 1H, J = 15.6 Hz, Hꢀ3');
C
NMR (CDCl , 100.5 MHz): δ 19.21 (Cꢀ4 CH ), 21.57 (Cꢀ4" CH ), 109.59 (Cꢀ8 or Cꢀ10),
3
3
3
1
1
1
10.94 (Cꢀ3), 111.92 (Cꢀ8 or Cꢀ10), 115.13 (Cꢀ6), 124.95 (Cꢀ3'), 129.06 (Cꢀ2" and Cꢀ6"),
29.75 (Cꢀ3" and Cꢀ5"), 130.86 (Cꢀ5), 131.99, 141.65 (Cꢀ1" and Cꢀ4"), 146.12 (Cꢀ2'),
53.06, 154.71 (Cꢀ4 and Cꢀ9), 159.25, 167.22 (Cꢀ2 and Cꢀ7), 193.25 (Cꢀ1'); HRMS:
+
Calculated for C20
H
16
O
4
[M ꢀ H] 319.1049, found 319.2061.
(E)ꢀ3ꢀEthylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ8ꢀ(3ꢀpꢀtolylacryloyl)ꢀ2Hꢀchromenꢀ2ꢀone
(22).
Compound 22 was obtained from the reaction of 8ꢀacetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀ
chromenꢀ2ꢀone (14) with 4ꢀmethylbenzaldehyde as yellow solid in 73% yield by column
chromatography using ethyl acetate/petroleum ether (1:15 v/v) as an eluent. Melting point:
o
1
2
1
85ꢀ187 C; UV (Chloroform) λmax: 320.00 and 351.63 nm; IR (KBr) νmax: 3417.36 (OH),
923.86, 1704.60 (OCO), 1628.22 (CO), 1593.17, 1538.68, 1361.21, 1263.82, 1180.82,
ꢀ1
1
3
091.05, 844.64, 717.85 cm ; H NMR (CDCl , 300 MHz): δ 1.18 (t, 3H, J = 7.5 Hz,

Page 22 of 52
2
2
CH
2
3 3 2 3
CH ), 2.39, 2.40 (2s, 6H, Cꢀ4 and Cꢀ4" CH ), 2.69 (q, 2H, J = 7.5 Hz, CH CH ), 6.92 (d,
1
6
H, J = 9.0 Hz, Hꢀ6), 7.23ꢀ7.26 (m, 2H, Hꢀ3" and Hꢀ5"), 7.63ꢀ7.69 (m, 3H, Hꢀ2", Hꢀ5 and Hꢀ
1
3
"), 7.94 (d, 1H, J = 15.6 Hz, Hꢀ2'), 8.27 (d, 1H, J = 15.3 Hz, Hꢀ3'), 13.82 (brs, 1H, OH); C
NMR (CDCl , 75.5 MHz): δ 13.03 (CH CH ), 14.91 (Cꢀ4 CH ), 20.71 (CH CH ), 21.61 (Cꢀ
3
2
3
3
2
3
4
" CH ), 109.40, 112.68 (Cꢀ10 and Cꢀ8), 114.91 (Cꢀ6), 124.15 (Cꢀ3), 125.25 (Cꢀ3'), 129.07
3
(Cꢀ2" and Cꢀ6"), 129.55, 129.78 (Cꢀ3" and Cꢀ5"), 131.02 (Cꢀ5), 132.15, 141.57 (Cꢀ1" and Cꢀ
4"), 145.89 (Cꢀ2'), 146.32, 153.11 (Cꢀ4, Cꢀ9), 160.26 (Cꢀ7), 166.24 (Cꢀ2), 193.42 (Cꢀ1');
+
HRMS: Calculated for C22
H
20
O
4
[M ꢀ H] 347.1362, found 347.2312.
(
E)ꢀ8ꢀ[3ꢀ(4ꢀDimethylaminophenyl)acryloyl]ꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone
23). Compound 23 was obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀ
(
chromenꢀ2ꢀone (12) with 4ꢀdimethylaminobenzaldehyde as light yellow solid in 76% yield
o
by crystallization in methylene chloride/methanol system; Melting point: 226ꢀ228 C; UV
(Chloroform) λmax: 293.45 and 464.65 nm; IR (KBr) νmax: 3417.24 (OH), 2912.68, 1721.91
ꢀ1
(
OCO), 1609.85 (CO), 1574.87, 1488.84, 1366.18, 1167.45, 1031.73, 823.38, 699.07 cm ;
1
H NMR (CDCl
.14 (d, 1H, J = 0.3 Hz, Hꢀ3), 6.68 (d, 1H, J = 8.8 Hz, Hꢀ3" and Hꢀ5"), 6.90 (d, 1H, J = 9.5
Hz, Hꢀ6), 7.60ꢀ7.63 (m, 3H, Hꢀ2", Hꢀ5 and Hꢀ6"), 7.99 (d, 1H, J = 14.6 Hz, Hꢀ2'), 8.09 (d,
3 3 3
, 400 MHz): δ 2.40 (d, 3H, J = 0.3 Hz, Cꢀ4 CH ), 3.04 (s, 6H, 2 × NCH ),
6
1
3
1
H, J = 15.4 Hz, Hꢀ3'), 14.40 (brs, 1H, OH); C NMR (CDCl
3
, 100.5 MHz): δ 19.32 (Cꢀ4
CH ), 40.07 (2 × NCH ), 110.01 (Cꢀ8 or Cꢀ10), 110.81 (Cꢀ3), 111.87 (Cꢀ3" and Cꢀ5"), 115.21
3
3
(Cꢀ6), 120.31 (Cꢀ3'), 122.68 (Cꢀ8 or Cꢀ10), 130.21 (Cꢀ5), 131.47 (Cꢀ1", Cꢀ2" and Cꢀ6),
147.81 (Cꢀ2'), 152.51 (Cꢀ4"), 153.19, 154.72 (Cꢀ4 and Cꢀ9), 159.71, 167.50 (Cꢀ2 and Cꢀ7),
+
192.45 (Cꢀ1'); HRMS: Calculated for C21
H19NO
4
[M ꢀ H] 348.1314, found 348.2266.
(E)ꢀ8ꢀ[3ꢀ(4ꢀDimethylaminophenyl)acryloyl]ꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀ
one (24). Compound 24 was obtained from the reaction of 8ꢀacetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀ
methylꢀ2Hꢀchromenꢀ2ꢀone (14) with 4ꢀdimethylaminobenzaldehyde as yellow solid in 76%

Page 23 of 52
2
3
o
yield by crystallization in methylene chloride/methanol system. Melting point: 164ꢀ166 C;
UV (Chloroform) λmax: 296.28 and 461.96 nm; IR (KBr) νmax: 3432.47 (OH), 2926.89,
ꢀ1 1
1
707.40 (OCO), 1596.08 (CO), 1517.55, 1374.88, 1168.14, 1092.78, 809.93 cm ; H NMR
(
CDCl , 300 MHz): δ 1.18 (t, 3H, J = 7.5 Hz, CH CH ), 2.41 (s, 3H, Cꢀ4 CH ), 2.70 (q, 2H, J
3
2
3
3
=
7.5 Hz, CH CH ), 3.06 (s, 6H, 2 × NCH ), 6.71 (d, 2H, J = 9.0 Hz, Hꢀ3" and Hꢀ5"), 6.91 (d,
2 3 3
1H, J = 9.0 Hz, Hꢀ6), 7.64ꢀ7.68 (m, 3H, Hꢀ2", Hꢀ5 and Hꢀ6"), 8.01 (d, 1H, J = 15.3 Hz, Hꢀ2'),
1
3
8
.19 (d, 1H, J = 15.0 Hz, Hꢀ3'), 14.32 (brs, 1H, OH); C NMR (CDCl
CH ), 14.92 (Cꢀ4 CH ), 20.70 (CH CH ), 40.04 (2 × NCH ), 109.63 (Cꢀ8 or Cꢀ10),
11.86 (Cꢀ3", Cꢀ5"), 112.58 (Cꢀ8 or Cꢀ10), 114.92 (Cꢀ6), 120.59 (Cꢀ3'), 122.79, 123.86 (Cꢀ1"
3
, 75.5 MHz): δ 13.06
(CH
2
3
3
2
3
3
1
and Cꢀ3), 130.35 (Cꢀ5), 131.34 (Cꢀ2" and Cꢀ6"), 146.43 (Cꢀ4), 147.39 (Cꢀ2'), 152.42, 153.02,
160.52 (Cꢀ4", Cꢀ7 and Cꢀ9), 166.44 (Cꢀ2), 192.53 (Cꢀ1'); HRMS: Calculated for C23H23NO
4
+
[
M ꢀ H] 376.1627, found 376.2679.
(E)ꢀ7ꢀHydroxyꢀ8ꢀ[3ꢀ(4ꢀmethoxyphenyl)acryloyl]ꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone
(25).
Compound 25 was obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ
2ꢀone (12) with anisaldehyde as a light yellow solid in 71% yield by column chromatography
o
using ethyl acetate/petroleum ether (1:20 v/v) as an eluent. Melting point: 187ꢀ188 C; UV
(Chloroform) λmax: 321.41 and 381.88 nm; IR (KBr) νmax: 3425 (OH), 2926.11, 1739.86
ꢀ1
(
OCO), 1598.99 (CO), 1508.79, 1388.56, 1261.70, 1169.11, 1078.14, 1028.63, 834.86 cm ;
1
H NMR (CDCl , 400 MHz): δ 2.43 (s, 3H, Cꢀ4 CH ), 3.86 (s, 3H, OCH ), 6.19 (s, 1H, Hꢀ3),
3
3
3
6.95ꢀ6.97 (m, 3H, Hꢀ3′′, Hꢀ5′′ and Hꢀ6), 7.66ꢀ7.71 (m, 3H, Hꢀ2′′, Hꢀ5 and Hꢀ6′′), 7.97 (d, 1H,
13
3
J = 15.36 Hz, Hꢀ2′), 8.17 (d, 1H, J = 15.36 Hz, Hꢀ3′), 13.99 (s, 1H, OH); C NMR (CDCl ,
100.5 MHz): δ 19.25 (Cꢀ4 CH
3 3
), 55.25 (OCH ), 109.67 (Cꢀ8), 110.87 (Cꢀ3), 111.84 (Cꢀ10),
114.59 (Cꢀ3′′ and Cꢀ5′′), 115.36 (Cꢀ6), 123.95 (Cꢀ2′), 127.50 (Cꢀ1′′), 130.77 (Cꢀ5), 131.05
(Cꢀ2′′ and Cꢀ6′′), 146.08 (Cꢀ3′), 153.00 (Cꢀ9), 154.98 (Cꢀ4), 159.53 (Cꢀ7), 161.91 (Cꢀ4′′),

Page 24 of 52
2
4
+
1
67.45 (Cꢀ2), 192.97 (Cꢀ1'); HRMS: Calculated for C20
37.0887.
16 5
H O [M + H] 337.1076, found
3
(
E)ꢀ3ꢀEthylꢀ7ꢀhydroxyꢀ8ꢀ[3ꢀ(4ꢀmethoxyphenyl)acryloyl]ꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone
26). Compound 26 was obtained from the reaction of 8ꢀacetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ
(
2
Hꢀchromenꢀ2ꢀone (14) with anisaldehyde as light yellow solid in 73% yield by column
chromatography using ethyl acetate/petroleum ether (1:10 v/v) as an eluent. Melting point:
o
1
83ꢀ185 C; UV (Chloroform) λmax: 240.05, 316.74 and 377.67 nm; IR (KBr) νmax: 3400.56
(OH), 2967.30, 1709.88 (OCO), 1627.89 (CO), 1589.26, 1539.73, 1365.74, 1264.59,
ꢀ1 1
1170.87, 1092.97, 1029.52, 829.80 cm
H NMR (CDCl , 300 MHz): δ 1.18 (brs, 3H,
; 3
CH
2 3 3 2 3 3
CH ), 2.42 (s 3H, Cꢀ4 CH ), 2.69ꢀ2.71 (m, 2H, CH CH ), 3.86 (s, 3H, OCH ), 6.95ꢀ6.97
(m, 3H, H ꢀ3", Hꢀ5" and Hꢀ6), 7.70ꢀ7.73 (m, 3H, Hꢀ2", Hꢀ5 and Hꢀ6"), 7.96 (d, 1H, J = 15.0
13
Hz, Hꢀ2'), 8.23 (d, 1H, J = 15.3 Hz, Hꢀ3'), 13.92 (brs, 1H, OH); C NMR (CDCl
MHz): δ 13.06 (CH CH ), 14.95 (Cꢀ4 CH ), 20.72 (CH CH ), 56.39 (OCH ), 109.44, 112.68
Cꢀ8 and Cꢀ10), 114.52 (Cꢀ3" and Cꢀ5"), 114.95 (Cꢀ6), 123.89 (Cꢀ3'), 124.09, 127.68 (Cꢀ1"
and Cꢀ3), 130.94 (Cꢀ2", Cꢀ5 and Cꢀ6"), 145.79 (Cꢀ2'), 146.42, 153.09 (Cꢀ4, and Cꢀ9), 160.39,
3
, 75.5
2
3
3
2
3
3
(
20 5
162.04, 166.30 (Cꢀ2, Cꢀ4", and Cꢀ7), 193.21 (Cꢀ1'); HRMS: Calculated for C22H O [M +
+
Na] 387.1208, found 387.1210.
(E)ꢀ8ꢀ[3ꢀ(2,3ꢀDimethoxyphenyl)acryloyl]ꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (27).
Compound 27 was obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ
2ꢀone (12) with 2,3ꢀdimethoxybenzaldehyde as light yellow solid in 74% yield by
o
crystallization in methylene chloride/methanol system. Melting point: 181ꢀ183 C; UV
(Chloroform) λmax: 317.64 nm; IR (KBr) νmax: 3428.57 (OH), 2926.26, 1735.99 (OCO),
ꢀ
1597.69, 1477.20, 1364.05, 1271.52, 1222.68, 1188.54, 1066.50, 840.37, 747.85, 695.50 cm
1
1
;
H NMR (CDCl , 400 MHz): δ 2.41 (d, 3H, J = 1.5 Hz, Cꢀ4 CH ), 3.89, 3.94 (2s, 6H, 2 ×
3 3
3
OCH ), 6.15 (d, 1H, J = 1.5 Hz, Hꢀ3), 6.92 (d, 1H, J = 8.8 Hz, Hꢀ6), 6.99 (dd, 1H, J = 1.5 and

Page 25 of 52
2
5
8.1 Hz, Hꢀ4"), 7.12 (t, 1H, J = 8.0 Hz, Hꢀ5"), 7.44 (dd, 1H, J = 1.5 and 8.2 Hz, Hꢀ6"), 7.65 (d,
1
3
1
H, J = 8.8 Hz, Hꢀ5), 8.20 (d, 1H, J = 16.1 Hz, Hꢀ2'), 8.30 (d, 1H, J = 15.4 Hz, Hꢀ3');
, 100.5 MHz): δ 19.26 (Cꢀ4 CH ), 55.86, 61.64 (2 × OCH ), 109.74, (Cꢀ10 or
Cꢀ8), 111.00 (Cꢀ3), 112.02 (Cꢀ8 or Cꢀ10), 114.71 (Cꢀ4"), 115.16 (Cꢀ6), 119.83 (Cꢀ6"),
C
NMR (CDCl
3
3
3
124.47, 127.09 (Cꢀ3' and Cꢀ5"), 128.86 (Cꢀ1"), 131.03 (Cꢀ5), 140.51 (Cꢀ2'), 149.21, 153.01,
153.19, 154.74 (Cꢀ2", Cꢀ3", Cꢀ4 and Cꢀ9), 159.31, 167.13 (Cꢀ2 and Cꢀ7), 193.52 (Cꢀ1');
+
HRMS: Calculated for C21
H
18
O
6
[M ꢀ H] 365.1103, found 365.2158.
(E)ꢀ8ꢀ[3ꢀ(2,3ꢀDimethoxyphenyl)acryloyl]ꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀ
one (28). Compound 28 was obtained from the reaction of 8ꢀacetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀ
methylꢀ2Hꢀchromenꢀ2ꢀone (14) with 2,3ꢀdimethoxybenzaldehyde as yellow solid in 76%
yield by column chromatography using ethyl acetate/petroleum ether (1:15 v/v) as an eluent.
o
Melting point: 210ꢀ212 C; UV (Chloroform) λmax: 303.26 and 431.16 nm; IR (KBr) νmax
:
3432.64 (OH), 2923.45, 2658.28, 1717.00 (OCO), 1632.06 (CO), 1521.64, 1379.94, 1303.88,
ꢀ
1 1
1
172.45, 1068.49, 1024.16, 882.61, 844.36 cm H NMR (CDCl , 400 MHz): δ 1.15 (t, 3H,
; 3
J = 7.8 Hz, CH
2
CH
), 6.90 (d, 1H, J = 9.2 Hz, Hꢀ6), 6.97 (d, 1H, J = 8.3 Hz, Hꢀ4"), 7.12 (t, 1H,
J = 8.0 Hz, Hꢀ5"), 7.48 (d, 1H, J = 8.2 Hz, Hꢀ6"), 7.66 (d, 1H, J = 8.7 Hz, Hꢀ5), 8.26 (d, 1H,
3 3 2 3
), 2.39 (s, 3H, Cꢀ4 CH ), 2.67 (q, 2H, J = 7.8 Hz, CH CH ), 3.88, 3.92
(2s, 6H, 2 × OCH
3
1
3
J = 15.6 Hz, Hꢀ2'), 8.30 (d, 1H, J = 15.6 Hz, Hꢀ3'); C NMR (CDCl
3
, 100.5 MHz): δ 13.04
(
CH CH ), 14.92 (Cꢀ4 CH ), 20.74 (CH CH ), 55.86, 61.66 (2 × OCH ), 109.45, 112.72 (Cꢀ8
2
3
3
2
3
3
and Cꢀ10), 114.62, 114.90 (Cꢀ4" and Cꢀ6), 119.77 (Cꢀ6"), 124.16 (Cꢀ1" or Cꢀ3), 124.48,
127.29 (Cꢀ3' and Cꢀ5"), 129.00 (Cꢀ1" or Cꢀ3), 131.13 (Cꢀ5), 140.19 (Cꢀ2'), 146.38, 149.19,
153.02, 153.08 (Cꢀ2", Cꢀ3", Cꢀ4, and Cꢀ9), 160.24, 161.15 (Cꢀ2 and Cꢀ7), 193.59 (Cꢀ1');
+
HRMS: Calculated for C23
H
22
O
6
[M ꢀ H] 393.1416, found 393.2555.
(E)ꢀ8ꢀ[3ꢀ(2,4ꢀDimethoxyphenyl)acryloyl]ꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (29).
Compound 29 was obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ

Page 26 of 52
2
6
2ꢀone (12) with 2,4ꢀdimethoxybenzaldehyde as yellow solid in 76% yield by column
chromatography using ethyl acetate/petroleum ether (1:15 v/v) as an eluent; Melting point:
o
2
16ꢀ218 C; UV (Chloroform) λmax: 266.98, 313.95 and 403.26 nm; IR (KBr) νmax: 3433.54
(OH), 2936.80, 1727.36 (OCO), 1606.46 (CO), 1527.31, 1492.50, 1317.01, 1232.33,
ꢀ
1 1
1
3
2
189.19, 1079.75, 993.82 cm ; H NMR (CDCl , 300 MHz): δ 2.43 (s, 3H, Cꢀ4 CH ), 3.87,
3
3
.98 (2s, 6H, 2 × OCH
3
), 6.17 (s, 1H, Hꢀ3), 6.48 (d, 1H, J = 2.1 Hz, Hꢀ3"), 6.57 (dd, 1H, J =
.1 and 8.4 Hz, Hꢀ5"), 6.94 (d, 1H, J = 9.0 Hz, Hꢀ6), 7.64ꢀ7.67 (m, 2H, Hꢀ5 and Hꢀ6"), 8.24
1
3
(
d, 1H, J = 15.3 Hz, Hꢀ2'), 8.39 (d, 1H, J = 15.6 Hz, Hꢀ3'), 14.28 (brs, 1H, OH); C NMR
(
CDCl , 100.5 MHz): δ 19.35 (Cꢀ4 CH ), 55.54, 55.62 (2 × OCH ), 98.37 (Cꢀ3"), 105.65 (Cꢀ
3
3
3
5
1
1
"), 109.98 (Cꢀ8 or Cꢀ10), 110.92 (Cꢀ3), 111.96 (Cꢀ8 or Cꢀ10), 115.27 (Cꢀ6), 117.18 (Cꢀ1"),
23.97 (Cꢀ3'), 130.52 (Cꢀ5), 132.85 (Cꢀ6"), 142.85 (Cꢀ2'), 153.21, 154.86, 159.68, 161.25,
63.69, (Cꢀ2", Cꢀ4, Cꢀ4", Cꢀ7 and Cꢀ9), 167.53 (Cꢀ2), 193.62 (Cꢀ1'); HRMS: Calculated for
+
C
21
H
18
O
6
[M ꢀ H] 365.1103, found 365.2152.
(E)ꢀ8ꢀ[3ꢀ(2,4ꢀDimethoxyphenyl)acryloyl]ꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀ
one (30). Compound 30 was obtained from the reaction of 8ꢀacetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀ
methylꢀ2Hꢀchromenꢀ2ꢀone (14) with 2,4ꢀdimethoxybenzaldehyde as yellow solid in 73%
yield by column chromatography using ethyl acetate/petroleum ether (1:15 v/v) as an eluent.
o
Melting point: 187ꢀ189 C; UV (Chloroform) λmax: 268.81, 382.85 and 401.57 nm; IR (KBr)
νmax: 3422.96 (OH), 2929.47, 1699.66 (OCO), 1628.09 (CO), 1537.48, 1359.92, 1274.02,
ꢀ
1
1
1
182.05, 1025.16, 828.92 cm ; H NMR (CDCl
CH CH ), 2.41 (s, 3H, Cꢀ4 CH ), 2.69 (q, 2H, J = 7.5 Hz, CH
OCH ), 6.48 (d, 1H, J = 2.4 Hz, Hꢀ3"), 6.57 (dd, 1H, J = 2.4 and 8.7 Hz, Hꢀ4"), 6.92 (d, 1H, J
9.0 Hz, Hꢀ6), 7.65ꢀ7.70 (m, 2H, Hꢀ5 and Hꢀ6"), 8.25 (d, 1H, J = 15.6 Hz, Hꢀ2'), 8.42 (d,
3
, 300 MHz): δ 1.18 (t, 3H, J = 7.5 Hz,
2
3
3
2
CH ), 3.86, 3.99 (2s, 6H, 2 ×
3
3
=
1
3
1
H, J = 15.6 Hz, Hꢀ3'), 14.19 (brs, 1H, OH); C NMR (CDCl , 75.5 MHz): δ 13.05
3
2 3 3 2 3 3
(CH CH ), 14.90 (Cꢀ4 CH ), 20.69 (CH CH ), 55.46, 55.57 (2 × OCH ), 98.25 (Cꢀ3"),

Page 27 of 52
2
7
105.58 (Cꢀ5"), 109.53, 112.56 (Cꢀ8 and Cꢀ10), 114.91 (Cꢀ6), 117.18 (Cꢀ1" or Cꢀ3), 123.89
(Cꢀ3'), 124.02 (Cꢀ1" or Cꢀ3), 130.60 (Cꢀ5), 132.46 (Cꢀ6"), 142.30 (Cꢀ2'), 146.35, 153.10,
160.42, 161.06, 163.54 (Cꢀ2", Cꢀ4, Cꢀ4", Cꢀ7 and Cꢀ9), 166.43 (Cꢀ2), 193.55 (Cꢀ1'); HRMS:
+
Calculated for C23
H
22
O
6
[M ꢀ H] 393.1416, found 393.2557.
(E)ꢀ8ꢀ[3ꢀ(2,5ꢀDimethoxyphenyl)acryloyl]ꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (31).
Compound 31 was obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ
2ꢀone (12) with 2,5ꢀdimethoxybenzaldehyde as a yellow solid in 76% yield by crystallization
o
in methylene chloride/methanol system. Melting point: 226ꢀ228 C; UV (Chloroform) λmax
:
313.02 and 409.3 nm; IR (Nujol) νmax: 3432.35 (OH), 2924.78, 1741.30 (OCO), 1617.80
ꢀ
1 1
(
CO), 1491.39, 1388.94, 1225.40, 1032.53, 858.13 cm ; H NMR (CDCl
d, 3H, J = 1.2 Hz, Cꢀ4 CH ), 3.87, 3.93 (2s, 6H, 2 × OCH
.87ꢀ7.00 (m, 3H, Hꢀ3", H ꢀ5" and Hꢀ6), 7.34 (d, 1H, J = 3.00 Hz, H ꢀ6"), 7.68 (d, 1H, J = 9.0
Hz, Hꢀ5), 8.29 (d, 1H, J = 15.9 Hz, Hꢀ2'), 8.42 (d, 1H, J = 15.6 Hz, Hꢀ3'), 14.04 (brs, 1H,
3
, 300 MHz): δ 2.44
(
3
3
), 6.17 (d, 1H, J = 0.9 Hz, Hꢀ3),
6
1
3
OH); C NMR (CDCl , 100.5 MHz): δ 19.08 (Cꢀ4 CH ), 55.82, 56.19 (2 × OCH ), 109.95
3
3
3
(Cꢀ10 or Cꢀ8), 110.85 (Cꢀ3), 112.03 (Cꢀ8 or Cꢀ10), 112.55 (Cꢀ6"), 113.09 (Cꢀ4"), 115.27 (Cꢀ
6
1
1
), 119.27 (Cꢀ3"), 124.17 (Cꢀ1"), 126.56 (Cꢀ3), 126.85 (Cꢀ3'), 130.88 (Cꢀ5), 141.57 (Cꢀ2'),
53.06, 153.48, 153.83, 154.92 (Cꢀ3", Cꢀ4, Cꢀ5" and Cꢀ9), 159.48, 167.45 (Cꢀ2 and Cꢀ7),
+
93.72 (Cꢀ1'), HRMS: Calculated for C21
H
18
O
6
[M ꢀ H] 365.1103, found 365.2107.
(E)ꢀ8ꢀ[3ꢀ(2,5ꢀDimethoxyphenyl)acryloyl]ꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀ
one (32). Compound 32 was obtained from the reaction of 8ꢀacetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀ
methylꢀ2Hꢀchromenꢀ2ꢀone (14) with 2,5ꢀdimethoxybenzaldehyde as a light yellow solid in
76% yield by crystallization in methylene chloride/methanol system. Melting point: 203ꢀ205
o
C; UV (Chloroform) λmax: 311.13 and 382.79 nm; IR (KBr) νmax: 3433.62 (OH), 2966.22,
723.47 (OCO), 1628.92, 1594.18, 1497.81, 1363.74, 1245.99, 1179.61, 1088.69, 991.80,
1
ꢀ1 1
8
3 2 3
76.34, 701.95 cm ; H NMR (CDCl , 300 MHz): δ 1.16 (t, 3H, J = 7.5 Hz, CH CH ), 2.40

Page 28 of 52
2
8
(
s, 3H, Cꢀ4 CH
.98 (m, 3H, Hꢀ3", Hꢀ5" and Hꢀ6), 7.33 (d, 1H, J = 3.00 Hz, Hꢀ6"), 7.67 (d, 1H, J = 9.0 Hz,
Hꢀ5), 8.26 (d, 1H, J = 15.6 Hz, Hꢀ2'), 8.43 (d, 1H, J = 15.6 Hz, Hꢀ3'), 13.95 (brs, 1H, OH);
3 2 3 3
), 2.68 (q, 2H, J = 7.5 Hz, CH CH ), 3.87, 3.93 (2s, 6H, 2 × OCH ), 6.87ꢀ
6
1
3
C NMR (CDCl , 75.5 MHz): δ 13.10 (CH CH ), 14.96 (Cꢀ4 CH ), 20.72 (CH CH ), 55.58,
3
2
3
3
2
3
5
1
1
6.13 (2 × OCH ), 109.55 (Cꢀ8 or Cꢀ10), 112.49 (Cꢀ6"), 112.71 (Cꢀ8 or Cꢀ10), 113.35 (Cꢀ4"),
3
14.93 (Cꢀ6), 118.94 (Cꢀ3"), 124.15, 124.23 (Cꢀ1" and Cꢀ3), 126.85 (Cꢀ3'), 130.98 (Cꢀ5),
41.36 (Cꢀ2'), 146.22, 153.26, 153.58, 153.80 (Cꢀ3", Cꢀ4, Cꢀ5" and Cꢀ9), 160.24, 166.37 (Cꢀ2
+
and Cꢀ7), 193.76 (Cꢀ1'); HRMS: Calculated for C23
93.2567.
H
22
O
6
[M ꢀ H] 393.1416, found
3
(
E)ꢀ8ꢀ[3ꢀ(3,4ꢀDimethoxyphenyl)acryloyl]ꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (33).
Compound 33 was obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ
ꢀone (12) with 3,4ꢀdimethoxybenzaldehyde as yellow solid in 62% yield by column
2
chromatography using ethyl acetate/petroleum ether (1:20 v/v) as an eluent. Melting point:
o
1
2
1
98ꢀ199 C; UV (Chloroform) λmax: 310.63 and 391.81 nm; IR (KBr) νmax: 3464.25 (OH),
372.34, 1718.57 (OCO), 1599.35 (CO), 1517.64, 1344.28, 1264.36, 1233.65, 1188.73,
ꢀ1 1
083.82, 1021.96, 858.76, 723.32 cm ; H NMR (CDCl
), 3.94, 4.00 (2s, 6H, 2 × OCH ), 6.16 (s, 1H, Hꢀ3), 6.91ꢀ6.95 (m, 2H, Hꢀ5′′ and Hꢀ6′′),
.25 (d, 1H, J = 8.8 Hz, Hꢀ6), 7.39 (s, 1H, Hꢀ2′′), 7.67 (d, 1H, J = 8.76 Hz, Hꢀ5), 7.93 (d, 1H,
3
, 400 MHz): δ 2.43 (s, 3H, Cꢀ4
CH
3
3
7
13
J = 15.4 Hz, Hꢀ2′), 8.27 (d, 1H, J = 15.4 Hz, Hꢀ3′), 14.15 (s, 1H, OH); C NMR (CDCl3,
100.5 MHz): δ 19.35 (Cꢀ4 CH
3 3
), 55.97 (2 x OCH ), 109.5 (Cꢀ3), 110.87, 110.93 (Cꢀ5′′ and Cꢀ
6′′), 112.00 (Cꢀ8 or Cꢀ10), 115.50 (Cꢀ2′′), 124.11 (Cꢀ6), 124.58 (Cꢀ2′), 127.99 (Cꢀ1′′), 130.87
(Cꢀ5), 146.14 (Cꢀ3′), 149.41 (Cꢀ4′′), 151.94 (Cꢀ3′′), 153.28 (Cꢀ9), 154.98 (Cꢀ4), 159.47 (Cꢀ7),
+
1
67.63 (Cꢀ2), 193.27 (Cꢀ1'); HRMS: Calculated for C21
66.1109.
H
18
O
6
[M] 366.1103, found
3

Page 29 of 52
2
9
(E)ꢀ8ꢀ[3ꢀ(3,4ꢀDimethoxyphenyl)acryloyl]ꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀ
one (34). Compound 34 was obtained from the reaction of 8ꢀacetylꢀ3ꢀethylꢀ7ꢀhydroxyꢀ4ꢀ
methylꢀ2Hꢀchromenꢀ2ꢀone (14) with 3,4ꢀdimethoxybenzaldehyde as yellow solid in 75%
o
yield by crystallization in methylene chloride/methanol system; Melting point: 170ꢀ172 C;
UV (Chloroform) λmax: 272.87, 310.77 and 392.89 nm; IR (KBr) νmax: 3434.17 (OH),
2933.95, 2370.28, 1721.70 (OCO), 1630.06(CO), 1595.87, 1490.17, 1381.04, 1266.59,
ꢀ
1 1
1165.53, 1087.25, 832.93, 768.21 cm
;
H NMR (CDCl
3
, 400 MHz): δ 1.11 (t, 3H, J = 7.3
Hz, CH
2
CH ), 2.31 (s, 3H, Cꢀ4 CH ), 2.60 (q, 2H, J = 7.3 Hz, CH
3
3
2
CH ), 3.88, 3.97 (2s, 6H, 2
3
x OCH ), 6.80 (d, 1H, J = 9.2 Hz, Hꢀ6), 6.83 (d, 1H, J = 8.5 Hz, Hꢀ5"), 7.19 (dd, 1H, J = 1.8
3
and 8.3 Hz, Hꢀ6"), 7.30 (d, 1H, J = 1.4 Hz, Hꢀ2"), 7.56 (d, 1H, J = 8.7 Hz, Hꢀ5), 7.81 (d, 1H,
1
3
J = 15.1 Hz, Hꢀ2'), 8.19 (d, 1H, J = 15.6 Hz, Hꢀ3'); C NMR (CDCl
3
, 100.5 MHz): δ 13.17
(CH
2
CH
3
), 14.99 (Cꢀ4 CH
3
), 20.76 (CH
2
CH
3
), 56.03, 56.14 (2 × OCH ), 109.23 (Cꢀ8 or Cꢀ
3
1
1
1
1
0), 109.77 (Cꢀ2"), 110.96 (Cꢀ5"), 112.69 (Cꢀ8 or Cꢀ10), 115.01 (Cꢀ6), 124.08 (Cꢀ1" or Cꢀ3),
24.26 (Cꢀ3'), 124.42 (Cꢀ6"), 128.14 (Cꢀ1" or Cꢀ3), 131.02 (Cꢀ5), 145.84 (Cꢀ2'), 146.39,
49.40, 151.87, 153.22 (Cꢀ3", Cꢀ4, Cꢀ4"and Cꢀ9), 160.20, 166.23 (Cꢀ2 and Cꢀ7), 192.99 (Cꢀ
+
'); HRMS: Calculated for C23
H
22
O
6
[M + Na] 417.1314, found 417.1337.
(E)ꢀ7ꢀHydroxyꢀ8ꢀ[3ꢀ(3ꢀhydroxyꢀ4ꢀmethoxyphenyl)acryloyl]ꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀ
one (35). Compound 35 was obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀ
chromenꢀ2ꢀone (12) with 3ꢀhydroxyꢀ4ꢀmethoxybenzaldehyde as light yellow solid in 70%
yield by column chromatography using ethyl acetate/petroleum ether (1:20 v/v) as an eluent.
o
Melting point: 198ꢀ200 C; UV (Chloroform) λmax: 313.24, 382.90 and 390.34 nm; IR (KBr)
ν
max: 3431.72 (OH), 2926.53, 1707.50 (OCO), 1601.78 (CO), 1508.69, 1376.29, 1282.14,
ꢀ1 1
1
; 3
132.51, 1037.08, 861.88, cm H NMR (CDCl , 300 MHz): δ 2.44 (d, 3H, J = 0.9 Hz, Cꢀ4
CH ), 3.96 (s, 3H, OCH ), 5.80 (brs, 1H, OH), 6.19 (d, 1H, J = 1.2 Hz, Hꢀ3), 6.89ꢀ6.96 (m,
3
3
2H, Hꢀ5" and Hꢀ6), 7.28ꢀ7.31 (m, 2H, Hꢀ2" and Hꢀ6"), 7.67 (d, 1H, J = 8.7 Hz, Hꢀ5), 7.91 (d,

Page 30 of 52
3
0
13
1
H, J = 15.3 Hz, Hꢀ2'), 8.12 (d, 1H, J = 15.6 Hz, Hꢀ3'), 13.91 (brs, 1H, OH); C NMR
(
DMSOꢀd , 100.5 MHz): δ 18.32 (Cꢀ4 CH ), 55.64 (OCH ), 110.55 (Cꢀ3), 111.93 (Cꢀ2"),
6
3
3
1
1
1
12.03 (Cꢀ8 or Cꢀ10), 112.80 (Cꢀ5"), 114.36 (Cꢀ6), 115.37 (Cꢀ8 or Cꢀ10), 122.23 (Cꢀ3'),
25.61 (Cꢀ6"), 126.93 (Cꢀ5), 127.17 (Cꢀ1"), 146.39 (Cꢀ4), 146.75 (Cꢀ2'), 150.59, 151.53
53.67 (Cꢀ3", Cꢀ4" and Cꢀ9), 158.27, 159.70 (Cꢀ2 and Cꢀ7), 192.12 (Cꢀ1'); HRMS:
+
Calculated for C20
H
16
O
6
[M ꢀ H] 351.0947, found 351.0983.
(E)ꢀ3ꢀEthylꢀ7ꢀhydroxyꢀ8ꢀ[3ꢀ(3ꢀhydroxyꢀ4ꢀmethoxyphenyl)acryloyl]ꢀ4ꢀmethylꢀ2Hꢀ
chromenꢀ2ꢀone (36). Compound 36 was obtained from the reaction of 8ꢀacetylꢀ3ꢀethylꢀ7ꢀ
hydroxyꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀone (14) with 3ꢀhydroxyꢀ4ꢀmethoxybenzaldehyde as
yellow solid in 71% yield by column chromatography using ethyl acetate/petroleum ether
o
(
1:20 v/v) as an eluent; Melting point: 189ꢀ191 C; UV (Chloroform) λmax: 273.22, 312.77
and 382.83 nm; IR (KBr) νmax : 3554.03 (OH), 2973.84, 1700.19 (OCO), 1624.48 (CO),
ꢀ1
1
1
598.00, 1439.26, 1368.01, 1266.26, 1134.33, 1031.30, 864.09, 615.95 cm ; H NMR
(
CDCl , 300 MHz): δ 1.18 (t, 3H, J = 7.2 Hz, CH CH ), 2.41 (s, 3H, Cꢀ4 CH ), 2.69 (q, 2H, J
3
2
3
3
=
2 3 3
7.2 Hz, CH CH ), 3.94 (s, 3H, OCH ), 5.99 (brs, 1H, OH), 6.89ꢀ6.94 (m, 2H, Hꢀ5" and Hꢀ
6), 7.27ꢀ7.29 (m, 2H, Hꢀ2" and Hꢀ6"), 7.68 (d, 1H, J = 9.0 Hz, Hꢀ5), 7.89 (d, 1H, J = 15.6 Hz,
1
3
Hꢀ2'), 8.18 (d, 1H, J = 15.3 Hz, Hꢀ3'), 13.87 (brs, 1H, OH); C NMR (CDCl
3
, 75.5 MHz): δ
1
1
1
1
3.03 (CH CH ), 14.95 (Cꢀ4 CH ), 20.70 (CH CH ), 55.96 (OCH ), 109.45 (Cꢀ8 or Cꢀ10),
2 3 3 2 3 3
10.81 (Cꢀ2"), 112.71 (Cꢀ8 or Cꢀ10), 114.21 (Cꢀ5"), 115.01 (Cꢀ6), 122.85 (Cꢀ3'), 124.10 (Cꢀ
" or C3), 124.35 (Cꢀ6"), 128.45 (Cꢀ1" or Cꢀ3), 131.93 (Cꢀ5), 145.95 (Cꢀ2'), 146.04, 146.56,
49.54, 153.06 (Cꢀ3", Cꢀ4, Cꢀ4"and Cꢀ9), 160.42, 166.32 (Cꢀ2 and Cꢀ7), 193.14 (Cꢀ1');
+
HRMS: Calculated for C22
H
20
O
6
[M + H] 381.1260, found 381.0983.
(E)ꢀ7ꢀHydroxyꢀ8ꢀ[3ꢀ(3ꢀhydroxyꢀ4ꢀmethoxyphenyl)acryloyl]ꢀ4ꢀmethylꢀ2Hꢀchromenꢀ2ꢀ
one (37). Compound 37 was obtained from the reaction of 8ꢀacetylꢀ7ꢀhydroxyꢀ4ꢀmethylꢀ2Hꢀ
chromenꢀ2ꢀone (12) with 4ꢀhydroxyꢀ3ꢀmethoxybenzaldehyde as orange solid in 61% yield by