Synthesis, molecular properties, anti-inflammatory and anticancer activities of novel 3-hydroxyflavone derivatives

Article abstract of DOI:10.1016/j.bioorg.2019.103009

A new series of 3-hydroxyflavones (1–46) were synthesized according to the Claisen-Schmidt followed by Algar-Flynn-Oyamada reactions (AFO) in one step. The synthesized flavonoids were characterized by ¹H NMR, ¹³C NMR and DCI-HRMS. All the synthesized compounds were tested in vitro for their 15-lipoxygenase inhibitory and cytotoxic activity against the human cell lines HCT-116 (Human colon carcinoma), IGROV-1 and OVCAR-3 (human ovarian carcinoma). It has been found that the derivatives 25, 37 and 45 were the most actives against HCT-116 (IC₅₀ = 8.0, 9.0 and 9.0 μM, respectively) and against IGROV-1 (IC₅₀ = 2.4, 5.0 and 6.0 μM, respectively). The derivatives 14 and 21 exhibited the higher anti-inflammatory activity at 100 μM with PI values of 76.50 and 72.70%, respectively. Molecule description was performed with DFT calculations, the drug likeness and bioactivity scores. The results exhibted that some compounds are in linear correlation with Lipinski's rule of five showing good drug likeness and bioactivity score for drug targets.

Full text of DOI:10.1016/j.bioorg.2019.103009

Accepted Manuscript
Review article
Synthesis, molecular properties, anti-inflammatory and anticancer activities of
novel 3-hydroxyflavone derivatives
Mansour Znati, Claire Bordes, Valérian Forquet, Pierre Lantéri, Hichem Ben
Jannet, Jalloul Bouajila
PII:
S0045-2068(19)30181-6
https://doi.org/10.1016/j.bioorg.2019.103009
103009
DOI:
Article Number:
Reference:
YBIOO 103009
Bioorganic Chemistry
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Revised Date:
Accepted Date:
4 February 2019
20 May 2019
21 May 2019
Please cite this article as: M. Znati, C. Bordes, V. Forquet, P. Lantéri, H. Ben Jannet, J. Bouajila, Synthesis, molecular
properties, anti-inflammatory and anticancer activities of novel 3-hydroxyflavone derivatives, Bioorganic
Chemistry (2019), doi: https://doi.org/10.1016/j.bioorg.2019.103009
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Synthesis, molecular properties, anti-inflammatory and anticancer activities of novel 3-
hydroxyflavone derivatives
Mansour Znatia,b, Claire Bordesc, Valérian Forquetc, Pierre Lantéric, Hichem Ben
Janneta,*, Jalloul Bouajilab,*
a
Laboratory of Heterocyclic Chemistry, Natural Products and Reactivity (LR11ES39), Team: Medicinal
Chemistry and Natural Products, Faculty of Science of Monastir, University of Monastir, Avenue of
Environment, 5019 Monastir, Tunisia
bUniversity of Toulouse, Paul-Sabatier University, Faculty of Pharmacy Toulouse, Laboratory of IMRCP UMR
CNRS 5623, 118 route de Narbonne, F-31062 Toulouse, France
cUniv Lyon, Université Claude Bernard Lyon 1, CNRS, ISA (Institut des Sciences Analytiques), UMR CNRS
n°5280, 5 rue de la Doua, F-69100 Villeurbanne, France
*Corresponding authors. J. Bouajila (Tel: +33562256885, Fax: +33562256885; E-mail:
jalloul.bouajila@univ-tlse3.fr); H. Ben Jannet (Tel: +21673500279, Fax: +21673500278; E-
mail: hichem.bjannet@gmail.com).
1

ABSTRACT
A new series of 3-hydroxyflavones (1-46) were synthesized according to the Claisen-Schmidt
followed by Algar-Flynn-Oyamada reactions (AFO) in one step. The synthesized flavonoids
1
13
were characterized by H NMR, C NMR and DCI-HRMS. All the synthesized compounds
were tested in vitro for their 15-lipoxygenase inhibitory and cytotoxic activity against the
human cell lines HCT-116 (Human colon carcinoma), IGROV-1 and OVCAR-3 (human
ovarian carcinoma). It has been found that the derivatives 25, 37 and 45 were the most actives
against HCT-116 (IC50 = 8.0, 9.0 and 9.0 µM, respectively) and against IGROV-1 (IC50 = 2.4,
5.0 and 6.0 µM, respectively). The derivatives 14 and 21 exhibited the higher anti-
inflammatory activity at 100 µM with PI values of 76.50 and 72.70%, respectively. Molecule
description was performed with DFT calculations, the drug likeness and bioactivity scores.
The results exhibted that some compounds are in linear correlation with Lipinski’s rule of five
showing good drug likeness and bioactivity score for drug targets.
Keywords: 3-hydroxyflavones; DFT calculations; 15-lipoxygenase inhibitory; cytotoxic
activity; drug likeness; molecular propreties.
2

1. Introduction
Flavonoids are phytochemical compounds that exist in two classes, either as free aglycones or
glycosylated. Chemically, they are polyphenols and have a phenyl-benzopyrone structure
(C6–C3–C6). The distinction of the subclasses of flavonoids is made according to the
conformation of the central structure (benzopyrone). It is possible to distinguish in particular
among the flavonoids the flavones, flavanols, isoflavones, flavonols, flavanones, flavanonols
and chalcones.1 This structural variety confers flavonoids a wide spectrum of biological
activities,2 including anticarcinogenic, anti-inflammatory,3 antimicrobial,4 spasmolytic and
antiviral activities.5 Moreover, they inhibit the capillary permeability, the platelet aggregation
and the lipid peroxidation. The ability of flavonoids to block the cell cycle, to induce
apoptosis,6 to disturb mitotic spindle formation or to inhibit angiogenesis makes them
promising agents in anti-cancer research.7,8 The last few years, flavonoids and their synthetic
analogs have been deeply investigated in the treatment of ovarian, breast, cervical, pancreatic,
and prostate cancers. Flavonoids such as genistein, quercetin or flavopiridol have entered late
phase clinical trials for several oncological indications.9-11 Flavonoids have been reported to
modulate several protein kinases (e.g. protein kinase-C) and to modulate epidermal growth
factor receptors (EGFRs), cyclin-dependent kinases (CDKs), vascular endothelial growth
factor receptors (VEGFRs) and platelet derived growth factor receptors (PDGFRs), which
play important roles in cancer diseases.12 The anti-inflammatory property of flavonoids have
been investigated in in vivo and in vitro models.13 Flavonoids are also known by their capacity
to inhibit several enzymes such as lipoxygenase (LOX), xanthine oxidase and cyclooxygenase
(COX) which are implicated in inflammatory diseases.14,15
Furthermore, flavonoids are able to modulate the functional activity of several types of cells.13
The different steps of inflammations are affected by the compounds including the formation
of granulose tissue, chronic arthritis as well as the permeability of capillaries in the early
3

stages,16 the structure-activity relationship study of 3-hydroxyflavones are of high interest.17
However, most research on the biological activity of flavonoids has been limited on natural
derivatives such as kaempferol, morin, galangin quercetin, fisetin, and myricetin.18-21
Taking into account the biological importance (anti-inflammatory, anticancer...) of this family
of natural compounds and in order to help enrich it with new bioactive derivatives, a series of
new flavonols were synthesized using a Claisen-Schmidt and Algar-Flynn-Oyamada reactions
(AFO) in one step, and a series of fourty-six compounds was tested in vitro for their 15-
lipoxygenase inhibitory and cytotoxic activity against the human cell lines HCT-116 (Human
colon carcinoma), IGROV-1 and OVCAR-3 (human ovarian carcinoma). Density functional
theory (DFT) calculations were performed with the PBE (Perdew, Burke and Ernzerhof) GGA
(Generalized Gradient Approximation) exchange-correlation functional method and a TZP
(triple zeta) basis set. The drug likeness of all synthesized compounds as well as of their
derivatives was determined and discussed.
2. Results and discussion
2.1. Synthesis
A one-step Claisen-Schmidt condensation followed by Algar-Flynn-Oyamada (AFO) reaction
was used to prepare the target 3-hydroxyflavones 1-46. As illustrated in Scheme 1, substituted
aryl aldehydes with substituted 2-hydroxyacetophenones were refluxed in methanol to afford
2-hydroxychalcones, then the intramolecular cyclization of the ring C and the oxidation of the
carbon 3 are carried out using (H2O2, NaOH) to give the desired flavonols (1-46) with yields
ranging from 30 to 92% after precipitation in ice-water.22 The prepared flavonols were
characterized by means of spectroscopic methods (1H, 13C-NMR and DCI-HRMS).
Compound 8, as an exemple, was obtained as a yellow solid. Its mass spectrum (DCI- HRMS)
gave pseudomolecular ion peak [M+H]+ at m/z 359.0292 in concordance with the molecular
1
formula C18H16BrO3. The H NMR (300 MHz, DMSO-d6) spectrum of compound 8 has
4

shown three signals at δH 8.16 (1H, d, J = 2.4 Hz), δH 7.87 (1H, dd, J1 = 9.0, J2 = 2.4 Hz) and
δH 7.72 (1H, d, J = 9.0 Hz) attributable to H-5, H-7 and H-8, respectively of the A-ring of the
flavonol skeleton. The same 1H NMR spectrum displayed an AA'BB' system of the B-ring at
δH 8.30 (2H, d, J = 8.4 Hz) and δH 7.39 (2H, d, J = 8.4 Hz) attributable to H-2', H-6' and H-3',
H-5', respectively. The presence of two signals at δH 3.02 (1H, sept, J = 6.9 Hz) and δH 1.26
13
(6H, d, J = 6.9 Hz) relative to the isopropyl fragment. The C NMR (75 MHz, DMSO-d6)
spectrum of 8 confirmed the above spectral data by the observation of signals at δC 174.8 (C-
4) attribuable to the carbonyl group, seven quaternary carbons at δC 153.3 (C-9), 149.4 (C-2),
145.8 (C-4'), 135.3 (C-3), 134.1 (C-7), 126.4 (C-1'), 125.5 (C-10) and five methine carbons at
δC 129.6 (C-5), 127.2 (C-2', C-6'), 126.6 (C-3', C-5'), 121.4 (C-8), 116.2 (C-6). The isopropyl
fragment was also identified by the observation of the corresponding carbon atoms at δC 33.8
(C-7') and 24.1 (C-8', C-9').
2.2. Biological assays
2.2.1.15-lipoxygenase inhibitory
The series of 3-hydroxyflavones 1-46 were evaluated for their ability to inhibit 15-
lipoxygenase enzyme and the corresponding Percent of Inhibition (PI) are given in Table 1.
All derivatives were tested at 100 µM. NDGA was used as a reference compound. The results
showed that this series of flavonols inhibits 5-LOX enzyme with PI values ranging from 0.7
and 76.5%. Compound 14 was found to exhibit the higher anti-5-LOX activity (PI = 76.5 ±
5.0%) followed by 21 (PI = 72.7 ± 3.5%) then 37 (PI = 54.9 ± 3.0%).
2.2.2. Cytotoxic activity
The cytotoxic activity of the synthesized compounds (1-46) were tested against three human
cancer cell lines including HCT-116, IGROV-1 and OVCAR-3 using the MTT assay.
Doxorubicin and Tamoxifen are employed as positive controls. The results expressed in IC50
are presented in Table 1. It was found that all the synthesized compounds displayed cytotoxic
5

activity towards HCT-116, IGROV-1 and OVCAR-3 with IC50 values ranging from 2.4 to
>100 µM.
Compounds 25, 37, 45 and 46 exhibited the highest activity against HCT-116 cell line (IC50 =
8.0-9.0 µM). Furthermore, compounds 12 and 20 displayed an interesting activity with an
IC50 value of 10 µM. Most of the rest of the compounds showed activity aganist the same cell
line (HCT-116) with IC50 values ranging from 18.0 to 95.0 µM. Regarding the human ovarian
carcinoma cell lines (IGROV-1 and OVCAR-3), compound 25 showed the most potent
activity against IGROV-1 with an IC50 value of 2.4 µM. However, compounds 37 and 45
displayed an interesting activity against IGROV-1 with IC50 values of 5.0 and 6.0 µM,
respectively, followed by compound 19 (IC50 = 10.0 µM). On the other hand, compounds 13,
17, 21 and 41 showed the highest activity towards OVCAR-3 with IC50 values of 11.5, 17.0,
19.0 and 18.0 µM, respectively. The results showed that most of the synthesized compounds
have cytotoxic profile against human cancer cell lines used, some compounds are found to be
more selective towards IGROV-1 than OVCAR-3. This finding can be explained by the
nature of the structure of these compounds and the specific sensitivity of IGROV-1 and
OVCAR-3 cell lines against them.
2.3. Bioactivity score of flavonols (1-46)
The bioactivity scores of the synthesized compounds for drug targets against G protein–
coupled receptors ligands (GPCR), nuclear receptor inhibitors, ion channel modulator, kinase
inhibitors and other enzyme targets based on Molinspiration software23 are presented in Table
2. The scores let it be identified of active, inactive molecules or moderately active. A
compound having bioactivity score above 0.00 is most likely to show considerable biological
activities, while values -0.50 to 0.00 are expected to be moderately active and if score is less
than -0.50 it is presumed to be inactive. However, G protein–coupled receptors (GPCR)
ligands results exhibited all compounds were found moderately active with bioactivity scores
6

ranged from -0.01 to -0.56. Except compounds 2, 32, 21 and 42 which were found to be
considerably bioactive with score values of 0.04, 0.09, 0.06 and 0.04, respectively. On the
other hand, the ion channel modulator and Protease inhibitor results, showed that all our
molecules were found to be moderately active or inactive having bioactivity score values
ranging from -0.04 to -0.56 and from -0.19 to -0.86, respectively. For the Kinase inhibitory
potential, 33 molecules from the series 1-46 were found to be active with bioactivity score
values of 0.01 - 0.30 (Table 2). A good number of synthesized compounds (27 molecules,
Table 2) were found to be considerably nuclear receptor inhibitors with bioactivity scores
ranging 0.01 to 0.30. However, the rest of compounds were moderately bioactive. Concerning
the Enzyme inhibitory potential, only 16 molecules were found to be moderately active with
bioactive score values ranging from -0.01 to -0.33, whereas 30 molecules showed good
bioactivity (scores = 0.02 - 0.27).
2.4. Drug likeness score of flavonols (1-46)
In order to evaluate if the synthesized flavonols 1-46 present a correlation between the
activity and the lipophilicity, and to better understand their overall properties , their physico-
chemical properties have been assessed using Molinspiration software23 and presented in
Table 3. The LogP of compounds 4, 5, 7, 8, 9, 10, 14, 17, 19, 20, 23, 26, 30, 31 and 45 were
found greater than five, indicating that these molecules have poor permeability across the cell
membrane (Table 3). The values of LogP less than five for the rest of the molecules, justify
their good permeability and therefore are an indication of a good lipid solubility that will help
the drug to interact with the membranes and to be used for generation of bioactivity. On the
other hand, the molecular weight of the molecule is an important parameter in pharmaceutics
drug action which acts by affecting the drug mechanisms when it increases beyond certain
limit. All molecular weights of the synthesized flavonols 1-46 are less than 500 g/mol
suggesting that these compounds are anticipated to be easily transported, diffused and
7

absorbed. Polar surface area (TPSA) calculated values are between 50.439 and 105.497 Ǻ2,
these resutls are a very good descriptor characterizing drug absorption with increasing
molecules flexibility and facilitating their interaction with a particular binding pocket.
Number of hydrogen bond acceptors (O and N atoms) and number of hydrogen bond donors
(NH and OH) of all the tested flavonols were found under 10 and 5, respectively and were in
agreement with the Lipinski’s rule of five. Interestingly, all compounds exhibited number of
violation (n violations) =1 or <0 meaning that are easily bind to receptor. As shown, the
determined molecular properties of these compounds justify their possible use as drugs.
2.5. Structure–activity relationship (SAR) analysis
The structure–activity relationship (SAR) analysis of the 5-LOX inhibition and cytotoxic
activity of flavonols derivatives (1-46) showed that 14 (PI = 76.5%) was found to be the most
active against 5-LOX enzyme. This results can be explained by the presence of the bromine
atom at C-6 on ring A and methylthiopheneheterocyclic on ring B. Furthermore, Beers and
their collaborators have been shown the effect of thiophene heterocyclic against 5-
lipoxygenase enzyme.24 However, the dihydrobenzofuran system on ring B (21) showed an
interesting activity with PI value of 72.7%, which was confirmed by Janusz.25
On the other hand, the meta 1,1,2,2-tetrafluoroethoxy on the ring B (19, 25, 3745 and 46)
showed the good cytotoxic activity against HCT-116 and IGROV-1 with IC50 values ranging
from 2.4 to 9 µM. These interesting results can be explained by the effect of fluorine atom.26
Liu et al. synthesized a series of novel flavone derivatives bearing chloride, isopropyl and
methoxy groups to develop effective anticancer agents possess notable activity against
hepatocarcinoma cells (HepG-2).27 SAR depicts that substitution at C-6 chloro at ring-A, is
important for anticancer activity.
8

Forthemore, the highest activity was obtained by compounds 25 and 37 against HCT-116 and
IGROV-1 due to the ability of these compounds to penetrate the cell membrane (LogP < 5).
The human genome encodes 538 protein kinases that transfer a γ-phosphate group from ATP
to tyrosine, threonine or serine residues. Many of these kinases are associated with human
cancer initiation and progression.28 Significantly, protein kinases are the second most targeted
group of drug targets, after the G-protein-coupled receptors.28 Flavonoids have been reported
to modulate several protein kinases.29,30 In our study, the results of in vitro cytotoxicity and
bioactivity testing showed that the most cytotoxic compounds (25, 37, 45 and 46) have proven
to be active inhibitors of protein kinase (bioactivity scores from 0.17 to 0.30) and moderately
active towards GPCR ligands. Our study suggests that flavonols could inhibit cancer cell
growth by acting on protein kinase signaling pathways more than as GPCRs ligands.
Moreover, the recent development of small-molecule kinase inhibitors for the treatment of
diverse types of cancer has proven successful in clinical therapy.28 In this study, Small
molecules with specific properties were investigated. Various mechanisms can lead to protein
kinase inhibition. Due to their low molecular weight (340.684 - 432.297 g/mol) and volume
(252.846 - 325.753 A˚3), these molecules can easily pass across cancer cell membranes by
diffusion. Furthermore, LogP values (≤ 5) indicate that our compounds have the benefit of
having facilitated access to cancer cells.
Finaly, analyzing the obtained data, moderate linear correlations were observed between the
biological activities and the lipophilicity of the synthesized flavonol derivatives 1-46, except
compound 19 with the highest LogP value of 5.81 exhibited a good cytotoxic activity. To
further exploit the dataset, Linear Discriminant Analysis was used to investigate the possible
classification of the molecules in three categories (Table 4) from the 15 available descriptors
(10 DFT descriptors associated with the values of LogP, MW, TPSA, n-ON acceptors and
volume). Satisfactory results were obtained for each biologiocal activity since more than 70%
9

of the molecules were correctly classified from both the training and the cross-validated set.
As an example for HCT-116, Figure 1 represents the scatter plot of the molecules defined by
the discriminant functions. F1 and F2 discriminant functions explained 93.5% and 6.5% of the
variance, respectively. F1 clearly allowed discriminating classes 1 and 2, while F2 was also
needed to highlight class 3. The three corresponding linear classification functions included 7
molecular descriptors: 4 variables mainly related to the electronic properties of the molecules
(the molecular orbital energies LUMO and HOMO, the vertical electronic affinity A and the
nucleofugality (λN)) (Table 5) and 3 variables related to the molecule size and their polarity
(TPSA, MW and the volume). These classification functions were used to predict which class
a molecule is to be assigned to using the values taken for the 7 discriminant initial variables.
These predictions were used to evaluate the performance of the LDA model. Moreover, LDA
model validation was carried out using a cross-validation method: 8 molecules among the 44
available molecules (~20% of the dataset) were randomly selected and used as validation set.
Results are presented in the so-called confusion matrix which gives the percentage of well
classified molecules, which is the ratio of the number of well-classified molecules over the
total number of molecules, for both the training and the validation sets of molecules (Tables 6
and 7). Satisfying results were obtained since about 80.6 and 75% of the molecules were
correctly classified from the training and the cross-validated set, respectively.
Results of equivalent statistical quality have been obtained for 15-lipoxygenase inhibitory,
OVCAR-3 and IGROV-1 activities. For 15-lipoxygenase inhibitory, the discriminant
functions only involved the number of hydrogen-bond acceptors (O and N atoms) and the
molecule hardness. For OVCAR-3, molecule classification was based on the nucleofugality
(λN), the volume and MW while for IGROV-1, it required the nucleofugality (λN), the dipole
moment and the molecule hardness.
3. Conclusion
10

We synthesized Forty-six novel flavonol analogues using a Claisen-Schmidt and AFO
reactions in one step and investigated their in vitro 15-lipoxygenase inhibitory effect and
cytotoxic activity against the human cell lines HCT-116, IGROV-1 and OVCAR-3. The
compounds 14, 21 and 37 showed the higher activity against 15-lipoxygenase enzyme.
Moreover, compound 14 possessing a bromine atom at C-6 on ring A and a methylthiophene
group on ring B demonstrated the highest activity against 15-lipoxygenase enzyme. On the
other hand, the majority of newly synthesized flavonols showed a good cytotoxicity against
HCT-116. Compounds 25, 37, 45 and 46 showed the highest activity against HCT-116.
However, compounds 25, 37, 45, 13, 17, 21 and 41 exhibited the highest cytotoxicity against
ovarian human cell lines (IGROV-1 and OVCAR-3). Furthermore, some compounds were
found to be more selective towards IGROV-1 than OVCAR-3. In conclusion, the most of the
synthesized compounds have cytotoxic profile against human cancer cell lines used. DFT
calculations and the drug likeness of all synthesized compounds performed reinforced the
biological results. Further, investigation into the mechanism of action of these flavonols
derivatives is our future work.
4. Experimental section
4.1. General methods
All reagents were purchased from Aldrich. All the solvents used in the syntheses were
technical grade and freshly distilled prior to use. DCI-HRMS was run in a GCT 1er Waters. 1H
(300 MHz) and 13C (75 MHz) NMR spectra were recorded on a Bruker AM-300
spectrometer, using DMSO-d6 as solvent and non deuterated residual solvent as internal
standard. Chemical shifts (δ) are given in parts per million (ppm) and coupling constants (J)
in Hz. Melting points were determined on a Büchi 510 apparatus using capillary tubes.
4.2. General procedure for 3-hydroxyflavone syntheses
11

In a round-bottom flask (25 mL), equipped with magnetic stirrer 2-hydroxyacetophenone (a)
(0.2 mL, 1.66 mmol), cumanaldehyde (b) (0.24 g, 1.66 mmol), sodium hydroxide (0.2 g, 5
mmol) and methanol (10 mL) were introduced. The pale yellow mixture was refluxed until
the color was changed into orange (about 3 hours). The reaction mixture was cooled to room
temperature and sodium hydroxide (0.5 N, 10 mL) and then hydrogen peroxide (35%, 0.684
mL) were added. After stirring 2-3 hours, the mixture was poured into ice-water and the
formed precipitate was filtered to obtain 1 as a yellow solid (75%).22
The following were similarly prepared 2-46.
4.2.1. 3-hydroxy-2-(4-isopropylphenyl)-4H-chromen-4-one (1). Yellow solid, yield: 75%,
mp: 238°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.27 (2H, d, J = 8.1 Hz, H-2', H-6'), 8.12
(1H, dd, J1 = 7.5, J2 = 1.2 Hz, H-5), 7.77 (2H, m, H-6, H-7), 7.46-7.42 (3H, m, H-8, H-3', H-
5'), 2.92 (1H, sept, J = 6.9 Hz, H-7'), 1.27 (6H, d, J = 6.9 Hz, H-8', H-9'). 13C NMR (75 MHz,
DMSO-d6) δC: 175.1 (C-4), 154.7 (C-9), 149.9 (C-4'), 145.5 (C-2), 133.4 (C-3), 130.3 (C-7),
129.6 (C-1'), 127.6 (C-2', C-6'), 126.7 (C-3', C-5'), 125.4 (C-5), 124.4 (C-6), 121.7 (C-10),
116.2 (C-8), 33.8 (C-7'), 24.1 (C-8', C-9'). DCI- HRMS [M+H]+ calcd. for (C18H17O3)+:
281.1178, found: 281.1183.
4.2.2. 2-(2,3-dihydrobenzofuran-5-yl)-3-hydroxy-4H-chromen-4-one (2). Yellow solid,
yield: 67%, mp: 255°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.71 (1H, s, H-2'), 8.51 (1H, d, J
= 7.8 Hz, H-6'), 8.04 (1H, J = 7.2 Hz, H-5), 7.58 (2H, m, H-6, H-7), 7.26 (1H, d, J = 6.3 Hz,
H-8), 6.81 (1H, d, J = 7.2 Hz, H-5'), 4.59 (2H, t, J = 7.2 Hz, H-7'), 3.26 (2H, t, J = 7.2 Hz, H-
13
8'). C NMR (75 MHz, DMSO-d6) δC: 175.0 (C-4), 158.7 (C-4'), 153.7 (C-9), 149.6 (C-2),
135.4 (C-3), 131.3 (C-7), 128.2 (C-2'), 127.0 (C-3'), 125.1 (C-5), 125.0 (C-6'), 123.3 (C-6),
122.8 (C-1'), 121.1 (C-10), 118.0 (C-8), 109.7 (C-5'), 71.4 (C-7'),29.6 (C-8'). DCI- HRMS
[M+H]+ calcd. for (C17H13O4)+: 281.0814, found: 281.0811.
12

4.2.3. 3-hydroxy-2-(4-methoxy-3-nitrophenyl)-4H-chromen-4-one (3). Yellow solid, yield:
90%, mp: 266°C; 1H NMR (300 MHz, DMSO-d6) δH: 9.55 (1H, d, J = 2.1 Hz,H-2'), 8.65 (1H,
dd, J1 = 8.4, J2 = 2.1 Hz, H-6'), 8.04 (1H, d, J = 7.8 Hz, H-5), 7.64 (1H, d, J = 8.4 Hz, H-5'),
7.59 (1H, d, J1 = 7.8, H-7), 7.28 (1H, dd, J1 = 7.8 Hz, H-6), 7.40 (1H, d, J = 7.8 Hz, H-8),
13
3.95 (3H, s, OCH3). C NMR (75 MHz, DMSO-d6) δC: 179.4 (C-4), 153.1 (C-9), 152.3 (C-
4'), 148.9 (C-2), 140.4 (C-3'), 138.7 (C-3), 130.7 (C-7), 130.7 (C-6'), 128.8 (C-2'), 128.2 (C-
5), 124.5 (C-6), 121.9 (C-10), 120.9 (C-1'), 117.6 (C-8), 113.8 (C-5'), 56.2 (OCH3). DCI-
HRMS [M+H]+ calcd. for (C16H12NO6)+: 314.0665, found: 316.0668.
4.2.4.3-hydroxy-2-(3-methylthiophen-2-yl)-4H-chromen-4-one (4). Orange solid, yield:
1
87%, mp: 260°C; H NMR (300 MHz, DMSO-d6) δH: 8.04 (1H, d, J = 7.5 Hz, H-5), 7.53
(2H, s, H-7, H-4'), 7.28 (1H, m, H-6), 7.23 (1H, m, H-8), 6.91 (1H, d, J = 4.1 Hz, H-3'),2.69
(3H, s, H-5'). 13C NMR (75 MHz, DMSO-d6) δC: 177.4 (C-4), 153.2 (C-9), 145.1 (C-2), 132.4
(C-3), 132.4 (C-7), 131.1 (C-4'), 131.0 (C-1'), 131.0 (C-2'), 129.4 (C-3'), 125.2 (C-5), 122.4
(C-10), 124.2 (C-6), 118.1 (C-8), 17.6 (C-5'). DCI- HRMS [M+H]+ calcd. for (C14H11O3S)+:
259.0429, found: 259.0438.
4.2.5.3-hydroxy-2-(4'-methoxy-[1,1'-biphenyl]-4-yl)-4H-chromen-4-one (5). Yellow solid,
yield: 87%, mp: 195°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.58 (2H, d, J = 8.7 Hz, H-2', H-
6'), 8.11 (10H, m, H-5, H-6, H-7, H-8, H-3', H-5', H-8', H-9', H-11', H-12'), 3.84 (3H, s, H-
13'). 13C NMR (75 MHz, DMSO-d6) δC: 173.5 (C-4), 160.3 (C-10'), 159.3 (C-9), 146.0 (C-2),
130.6 (C-3), 130.0- 114.7 (11 C-ar), 55.6 (C-13'). DCI- HRMS [M+H]+ calcd. for
(C22H17O4)+: 345.1127, found: 345.1133.
4.2.6.3-hydroxy-2-(4-morpholinophenyl)-4H-chromen-4-one (6). Orange solid, yield: 67%,
1
mp: 280°C; H NMR (300 MHz, DMSO-d6) δH: 8.18 (2H, d, J = 8.7 Hz, H-2', H-6'), 8.12
(1H, d, J = 7.8 Hz, H-5), 7.79 (1H, m, H-7), 7.13 (2H, d, J = 8.7 Hz, H-3', H-5'), 6.80 (1H, dd,
J1 = 7.8, J2 = 1.8 Hz, H-6), 6.68 (1H, dd, J1 = 8.7, J2 = 1.8 Hz, H-8), 3.79 (4H, m, H-8'), 3.30
13

(4H, m, H-7'). 13C NMR (75 MHz, DMSO-d6) δC: 172.7 (C-4), 152.1 (C-9), 151.5 (C-4'),
148.6 (C-2), 138.2 (C-3), 133.7 (C-7), 129.3 (C-2', C-6'), 125.1 (C-5), 124.8 (C-6), 121.8 (C-
10), 121.3 (C-1'), 117.8 (C-8), 114.2 (C-3', C-5'), 66.7 (C-8'), 47.6 (C-7'). DCI- HRMS
[M+H]+ calcd. for (C19H18NO4)+: 324.1236, found: 324.1243.
4.2.7.3-hydroxy-2-(3-(1,1,2,2-tetrafluoroethoxy)phenyl)-4H-chromen-4-one (7). Yellow
1
solid, yield: 43%, mp: 210°C; H NMR (300 MHz, DMSO-d6) δH: 8.95 (1H, s, H-2'), 8.40
(1H, d, J = 8.4 Hz, H-6'), 8.07 (1H, dd, J1 = 8.7, J2 = 1.2 Hz, H-5), 7.65-7.60 (2H, m, H-6, H-
8), 7.52 (1H, t, J = 8.1 Hz, H-5'), 7.31 (1H, m, H-7), 7.10 (1H, m, H-4'), 6.50 (1H, s, H-8').
13C NMR (75 MHz, DMSO-d6) δC: 180.5 (C-4), 154.1 (C-3'), 153.8 (C-9), 148.4 (C-2), 138.0
(C-3), 131.8 (C-7), 129.6 (C-5'), 129.6 (C-1'), 125.3 (C-5), 122.7 (C-6), 122.4 (C-10), 121.5
1
2
(C-4'), 118.5 (C-2'), 118.3 (C-6'), 118.3 (tt, JCF = 270.1, JCF = 31.0 Hz, C-7'), 108.9 (C-8),
1
2
108.4 (tt, JCF = 270.1, JCF = 31.0 Hz, C-8'). DCI- HRMS [M+H]+ calcd. for (C17H11F4O4)+:
355.0593, found: 355.0596.
4.2.8.6-bromo-3-hydroxy-2-(4-isopropylphenyl)-4H-chromen-4-one (8). Yellow solid,
yield: 81%, mp: 228°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.30 (2H, d, J = 8.4 Hz, H-2', H-
6'), 8.16 (1H, d, J = 2.4 Hz, H-5), 7.87 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-7), 7.72 (1H, d, J =
9.0 Hz, H-8), 7.39 (2H, d, J = 8.4 Hz, H-3', H-5'), 3.02 (1H, sept, J = 6.9 Hz, H-7'), 1.26 (6H,
d, J = 6.9 Hz, H-8', H-9'). 13C NMR (75 MHz, DMSO-d6) δC: 174.8 (C-4), 153.3 (C-9), 149.4
(C-2), 145.8 (C-4'), 135.3 (C-3), 134.1 (C-7), 129.6 (C-5), 127.2 (C-2', C-6'), 126.4 (C-1'),
126.6 (C-3', C-5'), 125.5 (C-10), 121.4 (C-8), 116.2 (C-6), 33.8 (C-7'), 24.1 (C-8', C-9'). DCI-
HRMS [M+H]+ calcd. for (C18H16BrO3)+: 359.0283, found: 359.0292.
4.2.9.6-bromo-3-hydroxy-2-(4-(trifluoromethyl)phenyl)-4H-chromen-4-one (9). Red solid,
yield: 88%, mp: 270°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.87 (2H, d, J = 8.4 Hz, H-3′,5′),
8.11 (1H, d, J = 2.4 Hz, H-5), 7.71 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-7), 7.71 (2H, d, J = 8.4
13
Hz, H-2′,6′), 7.64 (1H, d, J = 9.0 Hz, H-8). C NMR (75 MHz, DMSO-d6) δC: 179.5 (C-4),
14

154.9 (C-9), 141.8 (C-2), 139.3 (C-3), 139.3 (C-1′), 133.9 (C-7), 127.0 (C-5), 125.1 (q, 2JCF =
31.0 Hz, C-4′), 124.9 (q, 1JCF = 270.1 Hz, C-7′), 124.7 (q, 3JCF = 3.6 Hz, C-3′,5′), 124.5 (C-2',
C-6'), 122.7 (C-10), 121.1 (C-8), 114.5 (C-6). DCI- HRMS [M+H]+ calcd. for
(C16H9BrF3O3)+: 384.9687, found: 384.9680.
4.2.10. 6-bromo-2-(4-butoxyphenyl)-3-hydroxy-4H-chromen-4-one (10). Yellow solid, yield:
1
69%, mp: 288°C; H NMR (300 MHz, DMSO-d6) δH: 8.60 (2H, d, J = 8.7 Hz, H-2', H-6'),
8.12 (1H, d, J = 2.4 Hz, H-5), 7.71 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-7), 7.70 (1H, d, J1 = 9.0
Hz, H-8), 7.00 (2H, d, J = 8.7 Hz, H-3', H-5'), 4.03 (2H, t, J = 6.3 Hz, H-7'), 1.77 (2H, q, J =
6.3 Hz, H-8'), 1.53 (2H, six, J = 7.5 Hz, H-9'), 0.98 (3H, t, J = 7.5 Hz, H-10'). 13C NMR (75
MHz, DMSO-d6) δC: 175.9 (C-4), 158.0 (C-4'), 152.6 (C-9), 145.1 (C-2), 133.6 (C-7), 133.6
(C-3), 127.6 (C-5), 127.6 (C-6), 127.6 (C-2', C-6'), 127.5 (C-10), 123.4 (C-1'), 121.1 (C-8),
114.3 (C-3', C-5'), 67.5 (C-7'), 31.3 (C-8'), 19.2 (C-9'), 14.2 (C-10'). DCI- HRMS [M+H]+
calcd. for (C19H18BrO4)+: 389.0310, found: 389.0399.
4.2.11.
6-bromo-2-(2,3-dihydrobenzofuran-5-yl)-3-hydroxy-4H-chromen-4-one (11).
Yellow solid, yield: 67%, mp: 222°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.61 (1H, s, H-2'),
8.44 (1H, d, J = 7.8 Hz, H-6'), 8.08 (1H, d, J = 2.4 Hz, H-5), 7.68-7.44 (2H, m, H-7, H-8),
6.82 (1H, d, J = 7.2 Hz, H-5'), 4.95 (2H, t, J = 8.7 Hz, H-7'), 3.24 (2H, t, J = 8.7 Hz, H-8').
13C NMR (75 MHz, DMSO-d6) δC: 177.4 (C-4), 159.2 (C-9), 152.5 (C-4'), 145.5 (C-2), 133.4
(C-3), 133.4 (C-7), 127.9 (C-6), 127.7 (C-5), 126.3 (C-2'), 126.2 (C-3'), 123.4 (C-6'), 123.1
(C-1'), 121.1 (C-10), 115.0 (C-8), 108.9 (C-5'), 71.6 (C-7'),29.6 (C-8'). DCI- HRMS [M+H]+
calcd. for (C17H12BrO4)+: 358.9919, found: 358.9903
4.2.12.
6-bromo-3-hydroxy-2-(4-methoxy-3-nitrophenyl)-4H-chromen-4-one
(12).
1
Yellow solid, yield: 92%, mp: 280°C; H NMR (300 MHz, DMSO-d6) δH: 9.56 (1H, d, J =
2.1 Hz, H-2'), 8.65 (1H, d, J = 9.0 Hz, H-6'), 8.08 (1H, d, J = 2.1 Hz,H-5), 7.68 (1H, dd, J1 =
8.7, J2 = 2.1 Hz, H-7), 7.65 (1H, dd, J1 = 9.0, J2 = 2.1 Hz, H-5'),7.39 (1H, d, J = 8.7 Hz, H-8),
15

3.94 (3H, s,OCH3). 13C NMR (75 MHz, DMSO-d6) δC: 178.7 (C-4), 153.5 (C-9), 152.5 (C-4'),
149.2 (C-2), 141.2 (C-3'), 138.9 (C-3), 133.0 (C-7), 129.0 (C-6'), 128.4 (C-5), 128.4 (C-2'),
126.5 (C-6), 126.5 (C-10), 120.7 (C-1'), 114.1 (C-8), 113.6 (C-5'), 56.5 (OCH3). DCI- HRMS
[M+H]+ calcd. for (C16H11BrNO6)+: 391.9770, found: 391.9769.
4.2.13.
6-bromo-2-(4-chlorophenyl)-3-hydroxy-4H-chromen-4-one (13). Yellow solid,
yield: 69%, mp: 275°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.74 (2H, d, J = 9.0 Hz, H-2', H-
6'), 8.12 (1H, d, J = 2.4 Hz, H-5), 7.71 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-7), 7.63 (1H, d, J =
9.0 Hz, H-8), 7.44 (2H, d, J = 9.0 Hz, H-3’, H-5'). 13C NMR (75 MHz, DMSO-d6) δC: 179.3
(C-4), 154.1 (C-9), 152.7 (C-2), 142.9 (C-7), 134.7 (C-3), 133.7 (C-5), 130.1 (C-4'), 129.8 (C-
6), 128.1 (C-2', C-6'), 127.1 (C-1'), 126.7 (C-3', C-5'), 123.1 (C-10), 114.7 (C-8). DCI- HRMS
[M+H]+ calcd. for (C15H9BrClO3)+: 350.9424, found: 350.9423.
4.2.14.
6-bromo-3-hydroxy-2-(3-methylthiophen-2-yl)-4H-chromen-4-one
(14).
1
Orange solid, yield: 77%, mp: 288°C; H NMR (300 MHz, DMSO-d6) δH: 8.10 (1H, d, J =
2.4 Hz, H-5), 7.66 (1H, dd, J1 = 8.7, J2 = 2.4 Hz, H-7), 7.55 (1H, d, J = 8.7 Hz, H-8), 7.23
13
(1H, d, J = 5.1 Hz, H-4'), 6.92 (1H, d, J = 5.1 Hz, H-3'), 2.7 (3H, s, H-5'). C NMR (75
MHz, DMSO-d6) δC: 176.4 (C-4), 151.7 (C-9), 145.9 (C-2), 136.5 (C-3), 132.8 (C-7), 132.0
(C-4'), 131.0 (C-1'), 131.0 (C-2'), 127.0 (C-5), 124.3 (C-6), 123.9 (C-3'), 123.9 (C-10), 114.8
(C-8), 17.7 (C-5'). DCI- HRMS [M+H]+ calcd. for (C14H10BrO3S)+: 336.9534, found:
336.9526.
4.2.15.
6-bromo-2-(4-(diethoxymethyl)phenyl)-3-hydroxy-4H-chromen-4-one
(15).
1
Orange solid, yield: 64%, mp: 215°C; H NMR (300 MHz, DMSO-d6) δH: 8.65 (2H, d, J =
8.4 Hz, H-2', H-6'), 8.11 (1H, d, J = 2.4 Hz, H-5), 7.68 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-7),
7.61 (1H, d, J = 9.0 Hz, H-8), 7.40 (2H, d, J = 8.4 Hz, H-3', H-5'), 5.47 (1H, s, H-7'), 3.58
13
(4H, q, J = 7.2 Hz, H-8'), 1.16 (6H, t, J = 7.2 Hz, H-9'). C NMR (75 MHz, DMSO-d6) δC:
178.6 (C-4), 153.0 (C-9), 143.5 (C-2), 152.6 (C-4'), 136.1 (C-1'), 135.1 (C-3), 133.1 (C-7),
16

126.6 (C-6), 125.8 (C-5), 124.5 (C-2', C-6'), 122.6 (C-3', C-5'), 120.7 (C-10), 114.2 (C-8),
100.9 (C-7'),60.5 (C-8'), 15.1 (C-9'). DCI- HRMS [M+H]+ calcd. for (C20H20BrO5)+:
419.0494, found: 419.0498.
4.2.16. 6-bromo-3-hydroxy-2-(4-(methylthio)phenyl)-4H-chromen-4-one (16). Yellow solid,
yield: 76%, mp: 230°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.70 (2H, d, J = 9.0 Hz, H-2', H-
6'), 8.12 (1H, d, J = 2.1 Hz, H-5), 7.68 (1H, dd, J1 = 9.0, J2 = 2.1 Hz, H-7), 7.62 (1H, d, J =
13
9.0 Hz, H-8), 7.29 (2H, d, J = 9.0 Hz, H-3', H-5'), 2.51 (3H, s, H-7'). C NMR (75 MHz,
DMSO-d6) δC: 179.2 (C-4), 154.3 (C-9), 152.5 (C-4'), 143.9 (C-2), 135.1 (C-3), 133.2 (C-7),
132.8 (C-1'), 130.3 (C-6), 127.0 (C-5), 125.8 (C-2', C-6'), 125.6 (C-3', C-5'), 121.1 (C-10),
114.5 (C-8), 15.2 (C-7'). DCI- HRMS [M+H]+ calcd. for (C16H12BrO3S)+: 362.9691, found:
362.9689.
4.2.17.
6-bromo-2-(4-ethyl-3-nitrophenyl)-3-hydroxy-4H-chromen-4-one (17). Yellow
solid, yield: 88%, mp: 250°C; 1H NMR (300 MHz, DMSO-d6) δH: 9.54 (1H, d, J = 1.5 Hz,H-
2'), 8.59 (1H, dd, J1 = 8.1, J2 = 1.5 Hz, H-6'), 8.10 (1H, d, J = 2.1 Hz, H-5), 7.73 (1H, dd, J1 =
9.0, J2 = 2.1 Hz, H-7), 7.66 (1H, d, J = 9.0 Hz, H-8), 7.53 (1H, d, J = 8.1 Hz, H-5'),2.86 (2H,
q, J = 7.5 Hz, H-7'), 1.26 (3H, t, J = 7.5 Hz, H-8'). 13C NMR (75 MHz, DMSO-d6) δC: 179.3
(C-4), 154.0 (C-9), 149.5 (C-2), 141.6 (C-3'), 135.0 (C-3), 134.5 (C-4'), 134.1 (C-7), 131.0
(C-5'), 128.1 (C-6'), 127.1 (C-5), 127.1 (C-10), 123.0 (C-6), 121.3 (C-1'), 120.3 (C-2'), 114.8
(C-8), 25.5 (C-7'), 15.4 (C-8'). DCI- HRMS [M+H]+ calcd. for (C17H13BrNO5)+: 389.9977,
found: 389.9986.
4.2.18.
6-bromo-3-hydroxy-2-(4-morpholinophenyl)-4H-chromen-4-one (18). Orange
solid, yield: 60%, mp: 215°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.52 (2H, d, J = 8.4 Hz, H-
2', H-6'), 8.12 (1H, d, J = 2.1 Hz, H-5), 7.72 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-7), 7.64 (1H, d,
J = 9.0 Hz, H-8), 7.01 (2H, d, J = 8.4 Hz, H-3', H-5'), 3.78 (4H, m, H-8'), 3.21 (4H, m, H-7').
13C NMR (75 MHz, DMSO-d6) δC: 176.6 (C-4), 152.6 (C-9), 150.2 (C-4'), 149.3 (C-2), 133.7
17

(C-3), 133.6 (C-7), 127.4 (C-5), 127.4 (C-2', C-6'), 126.9 (C-10), 123.5 (C-6), 121.1 (C-1'),
115.2 (C-8), 114.4(C-3', C-5'), 66.5 (C-8'), 48.2 (C-7'). DCI- HRMS [M+H]+ calcd. for
(C19H17BrNO4)+: 402.0341, found: 402.0341.
4.2.19.
6-bromo-3-hydroxy-2-(3-(1,1,2,2-tetrafluoroethoxy)phenyl)-4H-chromen-4-
one (19). Yellow solid, yield: 60%, mp: 215°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.86 (1H,
s, H-2'), 8.37 (1H, d, J = 8.4 Hz, H-6'), 8.12 (1H, d, J = 2.4 Hz, H-5), 7.76 (1H, dd, J1 = 9.0,
J2 = 2.4 Hz, H-7), 7.68 (1H, d, J = 9.0 Hz, H-8), 7.54 (1H, t, J = 8.1 Hz, H-5'), 7.15 (1H, m,
H-4'), 6.62 (1H, m, H-8’). 13C NMR (75 MHz, DMSO-d6) δC: 178.6 (C-4), 152.9 (C-9), 152.9
(C-3'), 142.5 (C-2), 137.3 (C-3), 134.3 (C-7), 129.8 (C-5'), 129.8 (C-1'), 1274.1 (C-5), 123.0
1
2
(C-10), 123.0 (C-6), 121.4 (C-4'), 119.2 (C-2'), 118.7 (C-6'), 118.7 (tt, JCF = 270.1, JCF
=
31.0Hz, C-7'), 115.0 (C-8), 108.0 (tt, 1JCF = 270.1, 2JCF = 31.0 Hz, C-8'). DCI- HRMS [M+H]+
calcd. for (C17H10BrF4O4)+: 432.9699, found: 432.9699.
4.2.20.
6-bromo-2-(2-fluoro-4-(trifluoromethyl)phenyl)-3-hydroxy-4H-chromen-4-one
(20). Red solid, yield: 40%, mp: 165°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.19 (1H, d, J =
2.4 Hz, H-5), 8.13 (1H, d, J = 2.4 Hz, H-5'), 7.95 (1H, d, J = 9.0 Hz, H-2'), 7.83 (1H, dd, J1 =
9.0, J2 = 2.4 Hz, H-7), 7.71 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-2'), 7.49 (1H, d, J = 9.0 Hz, H-
13
8). C NMR (75 MHz, DMSO-d6) δC: 179.3 (C-4), 159.4 (C-2), 157.7 (C-6'), 153.7 (C-9),
145.2 (C-7), 135.2 (C-3), 134.2 (C-5), 132.5 (m, C-4'), 131.1 (d, 1JCF = 270.1 Hz,C-2'), 127.2
(C-10), 123.9 (d, 2JCF = 26.2 Hz, C-1'), 123.2 (q, 1JCF = 270.1 Hz, C-7'), 121.4 (m, C-3'), 116.1
(C-6), 114.7 (m, C-5'), 109.1 (C-8). DCI- HRMS [M+H]+ calcd. for (C16H8BrF4O3)+:
402.9593, found: 402.9606.
4.2.21.
6-chloro-2-(2,3 dihydrobenzofuran-5-yl)-3-hydroxy-4H-chromen-4-one (21).
Yellow solid, yield: 60%, mp: 256°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.57 (1H, s, H-2'),
8.40 (1H, d, J = 8.7 Hz, H-6'), 7.87 (1H, d, J = 2.4 Hz, H-5), 7.61 (1H, d, J = 9.0 Hz, H-5'),
7.49 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-7), 6.74 (1H, d, J = 8.7 Hz, H-8), 4.51 (2H, t, J = 8.4
18

13
Hz, H-7'), 3.17 (2H, t, J = 8.7 Hz, H-8'). C NMR (75 MHz, DMSO-d6) δC: 165.3 (C-4),
158.1 (C-9), 151.0 (C-4'), 147.3 (C-2), 136.1 (C-3), 130.6 (C-7), 129.7 (C-6), 126.8 (C-2'),
125.2 (C-5), 126.5 (C-3'), 124.1 (C-10), 122.0 (C-6'),121.1 (C-1'), 117.0 (C-8), 107.7 (C-5'),
71.4 (C-7'),30.0 (C-8'). DCI- HRMS [M+H]+ calcd. for (C17H12ClO4)+: 315.0424, found:
315.0427.
4.2.22.
6-chloro-2-(4-chlorophenyl)-3-hydroxy-4H-chromen-4-one (22). Yellow solid,
yield: 55%, mp: 260°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.70 (2H, d, J = 9.0 Hz, H-2', H-
6'), 7.97 (1H, d, J = 2.4 Hz, H-5), 7.72 (1H, d, J = 9.0 Hz, H-8), 7.63 (1H, dd, J1 = 9.0, J2 =
13
2.4 Hz, H-7), 7.46 (2H, d, J = 9.0 Hz, H-3', H-5'). C NMR (75 MHz, DMSO-d6) δC: 178.8
(C-4), 152.5 (C-9), 143.0 (C-2), 134.3 (C-3), 131.6 (C-7), 131.4 (C-5), 130.5 (C-4'), 129.8 (C-
6), 128.2 (C-2', C-6'), 127.1 (C-1'), 126.9 (C-3', C-5'), 123.8 (C-10), 121.1 (C-8). DCI- HRMS
[M+H]+ calcd. for (C15H9Cl2O3)+: 306.9929, found: 306.9923.
4.2.23.
6-chloro-3-hydroxy-2-(3-methylthiophen-2-yl)-4H-chromen-4-one
(23).
1
Orange solid, yield: 69%, mp: 270°C; H NMR (300 MHz, DMSO-d6) δH: 7.98 (1H, d, J =
2.4 Hz,H-5), 7.62 (1H, d, J = 9.0 Hz, H-8), 7.55 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-7), 7.23
13
(1H, d, J = 5.1 Hz, H-4'), 6.92 (1H, d, J = 5.1 Hz, H-3'), 2.71 (3H, s, H-5'). C NMR (75
MHz, DMSO-d6) δC: 175.1 (C-4), 150.1 (C-9), 149.9 (C-2), 144.4 (C-2'), 135.0 (C-3), 134.6
(C-7), 130.8 (C-1'), 128.8 (C-5), 129.6 (C-4'), 127.9 (C-6), 122.8 (C-10), 121.9 (C-3'), 119.1
(C-8), 16.3 (C-5'). DCI- HRMS [M+H]+ calcd. for (C14H10ClO3S)+: 293.0039, found:
293.0036.
4.2.24.
6-chloro-2-(4-(diethoxymethyl)phenyl)-3-hydroxy-4H-chromen-4-one
(24).
1
Orange solid, yield: 56%, mp: 215°C; H NMR (300 MHz, DMSO-d6) δH: 8.57 (2H, d, J =
8.4 Hz, H-2', H-6'), 7.95 (1H, d, J = 2.4 Hz, H-5), 7.67 (1H, d, J = 9.0 Hz, H-8), 7.55 (1H, dd,
J1 = 9.0, J2 = 2.4 Hz, H-7), 7.39 (2H, d, J = 8.4 Hz, H-3', H-5'), 5.46 (1H, s, H-7’), 3.52 (4H,
q, J = 6.3 Hz, H-8'), 1.16 (6H, t, J = 6.3 Hz, H-9'). 13C NMR (75 MHz, DMSO-d6) δC: 178.4
19

(C-4), 152.9 (C-9), 151.2 (C-1), 142.7 (C-3), ), 135.5 (C-7), 134.7 (C-4'), 129.8 (C-1'), 129.8
(C-6), 125.6 (C-5), 125.1 (C-2', C-6'), 123.7 (C-3', C-5'), 122.7 (C-10), 119.8 (C-8), 100.3 (C-
7'),59.9 (C-8'), 14.5 (C-9'). DCI- HRMS [M+H]+ calcd. for (C20H20ClO5)+: 375.0999, found:
375.1002.
4.2.25.
6-chloro-3-hydroxy-2-(4-(trifluoromethyl)phenyl)-4H-chromen-4-one
(25).
1
Red solid, yield: 76%, mp: 275°C; H NMR (300 MHz, DMSO-d6) δH: 8.83 (2H, d, J = 8.4
Hz, H-3′,5′), 7.95 (1H, d, J = 2.4 Hz, H-5), 7.66 (1H, d, J = 9.0 Hz, H-8), 7.66 (2H, d, J = 8.4
Hz, H-2', H-6'), 7.57 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-7). 13C NMR (75 MHz, DMSO-d6) δC:
179.6 (C-4), 154.7 (C-9), 141.9 (C-2), 139.3 (C-3), 139.3 (C-1′), 131.4 (C-7), 131.4 (C-6),
2
1
3
126.7 (C-5), 125.1 (q, JCF= 31.2 Hz, C-4′), 124.9 (q, JCF= 270.7 Hz, C-7′), 124.7 (q, JCF=
3.8 Hz, C-3′,5′), 124.6 (C-2′,6′), 122.1 (C-10), 120.9 (C-8). DCI- HRMS [M+H]+ calcd. for
(C16H9ClF3O3)+: 341.0192, found: 341.0187.
4.2.26.
6-chloro-3-hydroxy-2-(4'-methoxy-[1,1'-biphenyl]-4-yl)-4H-chromen-4-one
(26). Yellow solid, yield: 67%, mp: 180°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.67 (2H, d, J
= 8.1 Hz, H-2', H-6'), 8.14 (1H, s, H-5), 7.72-7.63 (6H, m, H-7, H-8, H-8', H-9', H-11', H-12'),
3.82 (3H, s, H-13'). 13C NMR (75 MHz, DMSO-d6) δC: 177.5 (C-4), 159.3 (C-10'), 152.9 (C-
9), 144.5 (C-2), 133.2 (C-3), 130.1- 114.7 (11C-ar), 55.6 (C-13'). DCI- HRMS [M+H]+ calcd.
for (C22H16ClO4)+: 379.0737, found: 379.0729.
4.2.27.
6-chloro-3-hydroxy-2-(4-(methylthio)phenyl)-4H-chromen-4-one (27). Yellow
solid, yield: 72%, mp: 210°C; 1H NMR(300 MHz, DMSO-d6) δH: 8.68 (2H, d, J = 8.7 Hz, H-
2', H-6'), 7.98 (1H, d, J = 2.4 Hz, H-5), 7.70 (1H, d, J = 9.0 Hz, H-8), 7.58 (1H, dd, J1 = 9.0,
J2 = 2.4 Hz, H-7), 7.30 (2H, d, J = 8.4 Hz, H-3', H-5'), 2.51 (3H, s, H-7'). 13C NMR (75 MHz,
DMSO-d6) δC: 179.0 (C-4), 153.5 (C-9), 152.2 (C-4'), 144.0 (C-2), 135.6 (C-3), 132.6 (C-7),
130.8 (C-6), 126.5 (C-5), 125.8 (C-2', C-6'), 125.8 (C-3', C-5'), 122.6 (C-1'), 120.9 (C-10),
20

120.9 (C-8), 15.2 (C-7'). DCI- HRMS [M+H]+ calcd. for (C16H12ClO3S)+: 319.0196, found:
319.0196.
4.2.28.
6-chloro-2-(4-ethyl-3-nitrophenyl)-3-hydroxy-4H-chromen-4-one (28). Yellow
1
solid, yield: 76%, mp: 260°C; H NMR (300 MHz, DMSO-d6) δH: 9.58 (1H, s, H-2'), 8.60
(1H, d, J = 6.0 Hz, H-6'), 7.96 (1H, s, H-5), 7.72 (1H, d, J = 6.9 Hz, H-7), 7.52 (2H, m, H-8,
13
H-5'), 2.83 (2H, q, J = 7.5 Hz, H-7'), 1.24 (3H, t, J = 7.5 Hz, H-8'). C NMR (75 MHz,
DMSO-d6) δC: 179.8 (C-4), 155.0 (C-9), 152.4 (C-2), 149.6 (C-3'), 141.5 (C-4'), 135.2 (C-3),
134.2 (C-7), 131.4 (C-5'), 130.7 (C-6'), 130.7 (C-6), 127.8 (C-5), 126.9 (C-10), 122.2 (C-1'),
120.8 (C-2'), 120.0 (C-8), 25.5 (C-7'), 15.4 (C-8'). DCI- HRMS [M+H]+ calcd. for
(C17H13ClNO5)+: 346.0482, found: 346.0486.
4.2.29.
6-chloro-3-hydroxy-2-(4-morpholinophenyl)-4H-chromen-4-one (29). Orange
solid, yield: 56%, mp: 200°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.53 (2H, d, J = 9.0 Hz, H-
2', H-6'), 7.96 (1H, d, J = 2.4 Hz, H-5), 7.72 (1H, d, J = 9.0 Hz, H-8), 7.61 (1H, dd, J1 = 9.0,
J2 = 2.4 Hz, H-7), 7.02 (2H, d, J = 9.0 Hz, H-3', H-5'), 3.79 (2H, m, H-8'), 3.22 (2H, m, H-7').
13C NMR (75 MHz, DMSO-d6) δC: 176.8 (C-4), 154.6 (C-2), 152.2 (C-9), 150.2 (C-4'), 137.8
(C-3), 131.9 (C-7), 129.0 (C-6), 127.3 (C-5), 127.3 (C-2', C-6'), 122.9 (C-10), 120.8 (C-8),
114.4 (C-3', C-5'), 113.6 (C-1'), 66.5 (C-8'), 48.3 (C-7'). DCI- HRMS [M+H]+ calcd. for
(C19H17ClNO4)+: 358.0846, found: 358.0853.
4.2.30.
6-chloro-3-hydroxy-2-(3-(1,1,2,2-tetrafluoroethoxy)phenyl)-4H-chromen-4-
one (30). Yellow solid, yield: 66%, mp: 245°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.90 (1H,
s, H-2'), 8.38 (1H, d, J = 8.1 Hz, H-6'), 7.97 (1H, d, J = 2.4 Hz, H-5), 7.75 (1H, d, J = 9.0 Hz,
H-8), 7.64 (1H, dd, J1 = 9.0, J2 = 2.4 Hz, H-7), 7.54 (1H, t, J = 8.1 Hz, H-5'), 7.14 (1H, m, H-
13
4'), 6.56 (1H, m, H-8’). C NMR (75 MHz, DMSO-d6) δC: 178.8 (C-4), 153.1 (C-9), 152.5
(C-3'), 148.4 (C-2), 137.5 (C-3), 131.6 (C-7), 129.7 (C-5'), 127.1 (C-5), 129.7 (C-1'), 129.7
1
2
(C-6), 122.8 (C-10), 121.1 (C-4'), 119.0 (C-2'), 118.2 (tt, JCF = 270.1, JCF = 31.0 Hz, C-7'),
21

119.0 (C-6'), 118.6 (C-8), 108.4 (tt, 1JCF = 270.1, 2JCF = 31.0 Hz, C-8'). DCI- HRMS [M+H]+
calcd. for (C17H10ClF4O4)+: 389.0204, found: 389.0209.
4.2.31.
6-chloro-2-(2-fluoro-4-(trifluoromethyl)phenyl)-3-hydroxy-4H-chromen-4-one
(31). Red solid, yield: 55%, mp: 185°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.05 (1H, d, J =
2.4 Hz, H-5), 7.98 (1H, d, J = 2.4 Hz, H-5'), 7.93 (1H, d, J = 9.0 Hz, H-2'), 7.72 (1H, dd, J1 =
9.0, J2 = 2.4 Hz, H-7), 7.64-7.52 (2H, m, H-2', H-8). 13C NMR (75 MHz, DMSO-d6) δC: 179.4
(C-4), 159.5 (C-2), 157.7 (C-6'), 153.9 (C-9), 145.2 (C-7), 132.6 (C-3), 131.6 (C-5), 131.1 (C-
4'), 131.1 (C-2'), 128.3 (C-6), 127.0 (C-10), 124.0 (C-1'), 123.4 (C-7'), 121.2 (C-3'), 114.5 (C-
5'), 109.2 (C-8). DCI- HRMS [M+H]+ calcd. for (C16H8ClF4O3)+: 359.0098, found: 359.0087.
4.2.32.
2-(2,3-dihydrobenzofuran-5-yl)-6-fluoro-3-hydroxy-4H-chromen-4-one (32).
1
Yellow solid, yield: 43%, mp: 260°C; H NMR (300 MHz, DMSO-d6) δH: 8.55 (1H, d, J =
2.1 Hz, H-5), 8.39 (1H, dd, J1 = 8.4, J2 = 2.1 Hz, H-7), 7.87 (1H, d, J = 3.0 Hz, H-2'), 7.72
(1H, d, J = 9.3 Hz, H-5'), 7.66 (1H, dd, J1 = 9.0, J2 = 3.0 Hz, H-6'), 6.83 (1H, d, J = 8.4 Hz,
H-8), 4.49 (2H, t, J = 8.7 Hz, H-7'), 3.25 (2H, t, J = 8.7 Hz, H-8'). 13C NMR (75 MHz,
DMSO-d6) δC: 176.8 (C-4), 158. 7 (C-9), 157.1 (d, 1JCF = 227.7 Hz, C-6), 155.6 (C-4'), 148.2
2
(C-2), 144.6 (C-3), 126.3 (C-3'), 125.9 (C-2'), 122.6 (d, JCF = 26.0 Hz, C-7), 121.8 (C-
2
6'),121.7 (C-8), 120.3 (C-10), 120.2 (C-1'), 119.1 (C-5'), 118.7 (d, JCF = 26.0 Hz, C-5), 70.9
(C-7'),29.0 (C-8'). DCI- HRMS [M+H]+ calcd. for (C17H12FO4)+: 299.0720, found: 299.0720.
4.2.33.
6-fluoro-3-hydroxy-2-(4-methoxy-3-nitrophenyl)-4H-chromen-4-one
(33).
1
Yellow solid, yield: 75%, mp: 280°C; H NMR (300 MHz, DMSO-d6) δH: 9.39 (1H, d, J =
2.1 Hz, H-2'), 8.63 (1H, dd, J1 = 9.0, J2 = 2.1 Hz, H-6'), 7.80 (1H, dd, J1 = 9.0, J2 = 2.1 Hz, H-
5), 7.70 (1H, dd, J1 = 9.0, J2 = 2.1 Hz, H-7), 7.56 (1H, m, H-5'),7.49 (1H, d, J = 9.0 Hz, H-8),
13
1
3.98 (3H, s, OCH3). C NMR (75 MHz, DMSO-d6) δC: 178.2 (C-4), 158.0 (d, JCF = 227.7
Hz, C-6), 156.4 (C-9), 150.7 (C-4'), 150.0 (C-2), 142.2 (C-3'), 139.5 (C-3), 130.6 (C-6'), 127.8
(C-2'), 122.8 (d, 2JCF = 26.0 Hz, C-7), 122.3 (C-10), 121.3 (C-1'), 120.9 (d, 2JCF = 26.0 Hz, C-
22

5), 120.3 (C-8), 114.4 (C-5'), 57.1 (OCH3). DCI- HRMS [M+H]+ calcd. for (C16H11FNO6)+:
332.0570, found: 332.0573.
4.2.34.
2-(4-butoxyphenyl)-6-fluoro-3-hydroxy-4H-chromen-4-one (34). Yellow solid,
yield: 40%, mp: 156°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.51 (2H, d, J = 9.3 Hz, H-2', H-
6'), 7.77 (1H, dd, J1 = 9.0, J2 = 2.1 Hz, H-5), 7.71 (1H, dd, J1 = 9.0, J2 = 3.0 Hz, H-8), 7.55
(1H, m, H-7), 7.03 (2H, d, J = 9.3 Hz, H-3', H-5'), 4.04 (2H, t, J = 6.6 Hz, H-7'), 1.77 (2H, q,
J = 6.6 Hz, H-8'), 1.53 (2H, six, J = 7.5 Hz, H-9'), 0.98 (3H, t, J = 7.5 Hz, H-10'). 13C NMR
(75 MHz, DMSO-d6) δC: 176.8 (C-4), 158.6 (C-4'), 158.1 (d, 1JCF = 227.7 Hz, C-6), 156.5 (C-
9), 147.3 (C-2), 145.4 (C-3), 128.1 (C-2', C-6'), 126.8 (C-10), 122.6 (d, 2JCF = 26.0 Hz, C-7),
122.5 (C-1'), 121.1 (C-8), 119.9 (d, 2JCF = 26.0 Hz, C-5), 114.4 (C-3', C-5'), 67.6 (C-7'), 31.2
(C-8'), 19.2 (C-9'), 14.2 (C-10'). DCI- HRMS [M+H]+ calcd. for (C19H18FO4)+: 329.1189,
found: 329.1187.
4.2.35.
6-fluoro-3-hydroxy-2-(4-(methylthio)phenyl)-4H-chromen-4-one (35). Yellow
solid, yield: 67%, mp: 190°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.44 (2H, d, J = 8.4 Hz, H-
2', H-6'), 7.80 (1H, dd, J1 = 9.0, J2 = 3.0 Hz, H-5), 7.73 (1H, dd, J1 = 8.7, J2 = 3.0 Hz, H-8),
13
7.60 (1H, m, H-7), 7.37 (2H, d, J = 8.4 Hz, H-3', H-5'), 2.54 (3H, s, H-7'). C NMR (75
1
MHz, DMSO-d6) δC: 176.1 (C-4), 158.2 (d, JCF = 227.7 Hz, C-6), 156.6 (C-9), 146.1 (C-2),
144.9 (C-4'), 138.6 (C-3), 127.1 (C-2', C-6'), 125.7 (C-3', C-5'), 122.6 (C-10), 122.9 (d, 2JCF
=
2
26.0 Hz, C-7), 122.5 (C-1'), 121.3 (C-8), 119.1 (d, JCF = 26.0 Hz, C-5), 14.9 (C-7'). DCI-
HRMS [M+H]+ calcd. for (C16H12FO3S)+: 303.0491, found: 303.0477.
4.2.36.
6-fluoro-3-hydroxy-2-(4-morpholinophenyl)-4H-chromen-4-one (36). Orange
solid, yield: 40%, mp: 190°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.52 (2H, d, J = 8.4 Hz, H-
2', H-6'), 7.78 (1H, dd, J1 = 9.0, J2 = 2.1 Hz, H-5), 7.87 (1H, dd, J1 = 9.0, J2 = 2.1 Hz, H-7),
7.66 (1H, dd, 9.0, J2 = 2.1 Hz, H-8), 7.10 (2H, d, J = 8.4 Hz, H-3', H-5'), 3.78 (2H, m, H-8'),
13
1
3.27 (2H, m, H-7'). C NMR (75 MHz, DMSO-d6) δC: 172.0 (C-4), 157.1 (d, JCF = 227.7
23

Hz, C-6), 152.2 (C-9), 150.1 (C-4'), 146.1 (C-2), 137.9 (C-3), 129.4 (C-2', C-6'), 129.4 (C-10),
121.4 (d, 2JCF = 26.0 Hz, C-7), 121.3 (C-1'), 121.0 (C-8), 119.4 (d, 2JCF = 26.0 Hz, C-5), 114.2
(C-3', C-5'), 66.4 (C-8'), 47.6 (C-7'). DCI- HRMS [M+H]+ calcd. for (C19H17FNO4)+:
342.1142, found: 342.1152.
4.2.37.
6-fluoro-3-hydroxy-2-(3-(1,1,2,2-tetrafluoroethoxy)phenyl)-4H-chromen-4-one
1
(37). Yellow solid, yield: 77%, mp: 185°C; H NMR (300 MHz, DMSO-d6) δH: 8.80 (1H, s,
H-2'), 8.37 (1H, d, J = 8.4 Hz, H-6'), 7.80 (1H, dd, J1 = 9.0, J2 = 3.0 Hz, H-5), 7.80 (1H, dd, J1
= 9.3, J2 = 3.0 Hz, H-7), 7.70 (1H, dd, J1 = 9.3, J2 = 3.0 Hz, H-8), 7.54 (1H, t, J = 8.1 Hz, H-
13
5'), 7.15 (1H, m, H-4'), 6.62 (1H, m, H-8'). C NMR (75 MHz, DMSO-d6) δC: 178.5 (C-4),
157.9 (d, 1JCF = 227.7 Hz, C-6), 156.3 (C-3'), 150.8 (C-9), 148.4 (C-2), 137.0 (C-3), 129.9 (C-
5'), 123.7 (C-1'), 122.2 (d, 2JCF = 26.0 Hz, C-7), 121.4 (C-10), 121.2 (C-8), 120.8 (C-6'), 119.7
(C-4'), 122.9 (C-2'), 120.1 (d, 2JCF = 26.0 Hz, C-5), 119.0 (C-2'), 119.0 (tt, 1JCF = 270.1, 2JCF =
2
31.0 Hz, C-7'), 109.0 (tt, 1JCF = 270.1, JCF = 31.0, Hz, C-8'). DCI- HRMS [M+H]+ calcd. for
(C17H10F5O4)+: 373.0499, found: 373.0491.
4.2.38.
2-(4-butoxyphenyl)-3-hydroxy-6-methoxy-4H-chromen-4-one (38). Yellow
solid, yield: 60%, mp: 160°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.22 (2H, d, J = 9.0 Hz, H-
2', H-6'), 7.56 (1H, d, J = 3.0 Hz, H-5), 7.52 (1H, d, J = 9.0 Hz, H-8), 7.31 (1H, dd, J1 = 9.0,
J2 = 3.0 Hz, H-7), 7.05 (2H, d, J = 9.0 Hz, H-3', H-5'), 4.07 (2H, t, J = 6.9 Hz, H-7'), 3.91
(3H, s, OCH3), 1.83 (2H, q, J = 6.9 Hz, H-8'), 1.56 (2H, six, J = 7.5 Hz, H-9'), 0.99 (3H, t, J
13
= 7.5 Hz, H-10'). C NMR (75 MHz, DMSO-d6) δC: 172.9 (C-4), 156.1 (C-4'), 153.0 (C-9),
150.0 (C-6), 145.1 (C-2), 131.0 (C-3), 129.1 (C-2', C-6'), 123.8 (C-1'), 123.0 (C-10), 120.8
(C-7), 119.3 (C-3', C-5'), 114.2 (C-8), 103.5 (C-5), 68.0 (C-7'), 55.6 (OCH3), 31.1 (C-8'), 18.5
(C-9'), 13.5 (C-10'). DCI- HRMS [M+H]+ calcd. for (C20H21O5)+: 341.1389, found: 341.1396.
4.2.39.
3-hydroxy-2-(4-isopropylphenyl)-6-methoxy-4H-chromen-4-one (39). Yellow
solid, yield: 57%, mp: 215°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.09 (2H, d, J = 8.7 Hz, H-
24

2', H-6'), 7.47 (1H, d, J = 3.0 Hz, H-5), 7.42 (1H, d, J = 8.7 Hz, H-8), 7.31 (2H, d, J = 8.7 Hz,
H-3', H-5'), 7.22 (1H, dd, J1 = 8.7, J2 = 3.0 Hz, H-7), 3.82 (3H, s, OCH3), 2.92 (1H, sept, J =
6.9 Hz, H-7'), 1.22 (6H, d, J = 6.9 Hz, H-8', H-9'). 13C NMR (75 MHz, DMSO-d6) δC: 172.9
(C-4), 156.7 (C-9), 150.4 (C6), 151.2 (C-4'), 145.2 (C-2), 137.8 (C-3), 128.6 (C-1'), 127.7 (C-
2', C-6'), 126.6 (C-3', C-5'), 124.2 (C-10), 119.6 (C-7), 119.6 (C-8), 103.7 (C-5), 55.8 (OCH3),
34.1 (C-7'),23.7 (C-8', C-9'). DCI- HRMS [M+H]+ calcd. for (C19H19O4)+: 311.1283, found:
311.1289.
4.2.40.
3-hydroxy-6-methoxy-2-(pyridin-4-yl)-4H-chromen-4-one (40). Orange solid,
yield: 30%, mp: 244°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.49-8.38 (4H, m, H-2', H-3', H-
5',H-6'), 7.57 (1H, d, J = 9.3 Hz, H-8), 7.35 (1H, d, J = 3.3 Hz, H-5), 7.24 (1H, dd, J1 = 9.3, J2
13
= 3.3 Hz, H-7), 3.82 (3H, s, OCH3). C NMR (75 MHz, DMSO-d6) δC: 180.4 (C-4), 155.6
(C-9), 151.2 (C-6), 149.5 (C-3', 5'), 142.3 (C-2), 139.9 (C-3), 139.9 (C-1'), 123.7 (C-10),
121.5 (C-7), 120.2 (C-2', C-6'), 118.1 (C-8),104.1 (C-5), 55.8 (OCH3). DCI- HRMS [M+H]+
calcd. for (C15H12NO4)+: 270.0766, found: 270.0768.
4.2.41.
2-(4-(diethoxymethyl)phenyl)-3-hydroxy-6-methoxy-4H-chromen-4-one (41).
1
Orange solid, yield: 60%, mp: 122 °C; H NMR (300 MHz, DMSO-d6) δH: 8.59 (2H, d, J =
8.7 Hz, H-2', H-6'), 7.62 (1H, d, J = 8.7 Hz, H-8), 7.46 (2H, d, J = 8.7 Hz, H-3', H-5'), 7.42
(1H, d, J = 2.1 Hz, H-5), 7.27 (1H, dd, J1 = 8.7, J2 = 2.1 Hz, H-7), 5.52 (1H, s, H-7'), 3.86
13
(3H, s, OCH3), 3.61-3.46 (4H, q, J = 6.9 Hz, H-8'), 1.20 (6H, t, J = 6.9 Hz, H-9'). C NMR
(75 MHz, DMSO-d6) δC: 177.4 (C-4), 153.9 (C-9), 149.0 (C-6), 148.0 (C-2), 136.5 (C-4'),
136.5 (C-1'), 134.0 (C-3), 125.3 (C-2', C-6'), 124.4 (C-3', C-5'), 121.0 (C-10), 120.9 (C-7),
119.0 (C-8), 102.9 (C-5), 100.3 (C-7'),59.9 (C-8'), 54.8 (OCH3), 14.0 (C-9'). DCI- HRMS
[M+H]+ calcd. for (C21H23O6)+: 371.1495, found: 371.1500.
4.2.42.
2-(2,3-dihydrobenzofuran-5-yl)-3-hydroxy-6-methoxy-4H-chromen-4-one
1
(42). Yellow solid, yield: 49%, mp: 180°C; H NMR (300 MHz, DMSO-d6) δH: 8.61 (1H, s,
25

H-2'), 8.44 (1H, d, J = 7.8 Hz, H-6'),7.62 (1H, d, J = 8.7 Hz, H-8), 7.42 (1H, d, J = 2.1 Hz, H-
5), 7.27 (1H, dd, J1 = 8.7, J2 = 2.1 Hz, H-7), 6.82 (1H, d, J = 7.2 Hz, H-5'), 4.61 (2H, t, J =
8.4 Hz, H-7'), 3.84 (3H, s, OCH3), 3.26 (2H, t, J = 8.4 Hz, H-8'). 13C NMR (75 MHz, DMSO-
d6) δC: 175.1 (C-4), 160.5 (C-9), 155.7 (C-6), 149.8 (C-4'), 145.7 (C-2), 136.9 (C-3), 127.8
(C-2'), 125.8 (C-3'), 124.3 (C-10), 122.6 (C-6'), 122.2 (C-7), 122.2 (C-1'),120.1 (C-9), 109.1
(C-5'), 104.1 (C-5), 71.8 (C-7'),56.0 (OCH3), 29.4 (C-8'). DCI- HRMS [M+H]+ calcd. for
(C18H15O5)+: 311.0919, found: 311.0912.
4.2.43.
2-(4-chlorophenyl)-3-hydroxy-6-methoxy-4H-chromen-4-one (43). Yellow
solid, yield: 53%, mp: 218°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.50 (2H, d, J = 8.7 Hz, H-
2', H-6'), 7.62 (1H, d, J = 8.7 Hz, H-8), 7.49 (2H, d, J = 8.7 Hz, H-3', H-5'), 7.40 (1H, d, J =
13
3.0 Hz, H-5), 7.29 (1H, dd, J1 = 8.7, J2 = 3.0 Hz, H-7), 3.84 (3H, s, OCH3). C NMR (75
MHz, DMSO-d6) δC: 177.2 (C-4), 155.4 (C-9), 149.5 (C-6), 147.4 (C-2), 138.9 (C-3), 133.2
(C-4'), 131.9 (C-1'), 128.5 (C-2', C-6'), 128.0 (C-3', C-5'), 122.7 (C-10), 122.0 (C-7), 120.5
(C-8), 113.6 (C-5), 55.9 (OCH3). DCI- HRMS [M+H]+ calcd. for (C16H12ClO4)+: 303.0424,
found: 303.0421.
4.2.44.
3-hydroxy-6-methoxy-2-(4-morpholinophenyl)-4H-chromen-4-one
(44).
1
Orange solid, yield: 44%, mp: 180°C; H NMR (300 MHz, DMSO-d6) δH: 8.17 (2H, d, J =
9.0 Hz, H-2', H-6'), 7.73 (1H, d, J = 8.7 Hz, H-8), 7.45 (1H, d, J = 3.0 Hz, H-5), 7.41 (1H, dd,
J1 = 9.0, J2 = 3.0 Hz, H-7), 7.12 (2H, d, J = 9.0 Hz, H-3', H-5'), 3.89 (3H, s, OCH3), 3.78 (2H,
13
m, H-8'), 3.30 (2H, m, H-7'). C NMR (75 MHz, DMSO-d6) δC: 172.3 (C-4), 156.3 (C-9),
156.3 (C-4'), 149.7 (C-6), 146.4 (C-2), 137.9 (C-3), 129.2 (C-2', C-6'), 123.4 (C-7), 122.4 (C-
10), 121.4 (C-8), 121.4 (C-1'), 114.2 (C-3', C-5'), 104.3 (C-5), 66.5 (C-8'), 56.1 (OCH3), 47.6
(C-7'). DCI- HRMS [M+H]+ calcd. for (C20H20NO5)+: 354.1341, found: 354.1346.
4.2.45.
3-hydroxy-6-methoxy-2-(3-(1,1,2,2-tetrafluoroethoxy)phenyl)-4H-chromen-4-
one (45). Yellow solid, yield: 55%, mp: 260°C; 1H NMR (300 MHz, DMSO-d6) δH: 8.64 (1H,
26

s, H-2'), 8.32 (1H, d, J = 8.1 Hz, H-6'), 7.68 (1H, d, J = 9.0 Hz, H-8), 7.59 (1H, t, J = 8.1 Hz,
H-5'), 7.42 (1H, d, J = 2.7 Hz, H-5), 7.33 (1H, dd, J1 = 9.0, J2 = 3.0 Hz, H-7), 7.24 (1H, m, H-
13
4'), 6.50 (1H, m, H-8'), 3.87 (3H, s, OCH3). C NMR (75 MHz, DMSO-d6) δC: 177.4 (C-4),
155.4 (C-3'), 155.4 (C-9), 149.6 (C-6), 148.5 (C-2), 136.4 (C-3), 130.2 (C-5'), 123.6 (C-1'),
122.9 (C-10), 122.0 (C-7), 120.3 (C-8), 120.1 (C-4'), 119.5 (tt, 1JCF = 270.1, 2JCF = 31.0 Hz, C-
1
2
7'), 118.9 (C-6'), 117.0 (C-2'), 108.3(tt, JCF = 270.1, JCF = 31.0 Hz, C-8'), 104.1 (C-5), 55.9
(OCH3). DCI- HRMS [M+H]+ calcd. for (C18H13F4O5)+: 385.0699, found: 385.0705.
4.2.46.
3-hydroxy-7,8-dimethoxy-2-(3-(1,1,2,2-tetrafluoroethoxy)phenyl)-4H-
1
chromen-4-one (46). Orange solid, yield: 43%, mp: 160°C; H NMR (300 MHz, DMSO-d6)
δH: 8.57 (1H, s, H-2'), 8.33 (1H, d, J = 8.1 Hz, H-6'), 7.83 (1H, d, J = 9.0 Hz, H-5), 7.62 (1H,
t, J = 8.1 Hz, H-5'), 7.23 (2H, m, H-4', H-6), 6.53 (1H, m, H-8'), 3.96, 3.94 (6H, s, OCH3). 13C
NMR (75 MHz, DMSO-d6) δC: 177.4 (C-4), 155.6 (C-3'), 148.9 (C-9), 148.5 (C-7), 142.1 (C-
2), 136.5 (C-3), 136.4 (C-8), 130.2 (C-5'), 130.2 (C-1'), 120.8 (C-4'), 120.1 (C-6'), 118.8 (tt,
2
1
1JCF = 270.1, JCF = 31.0 Hz, C-7'),118.8 (C-10), 117.0 (C-5), 110.2 (C-2'), 110.2 (tt, JCF
=
270.1, 2JCF = 31.0 Hz, C-8'), 108.3 (C-6), 61.2, 56.9 (OCH3). DCI- HRMS [M+H]+ calcd. for
(C19H15F4O6)+: 415.0805, found: 415.0806.
4.3. 15-lipoxygenase inhibitory
The 15-lipoxygenase inhibitory of 3-hydroxyflavones derivatives (1-46) was determined on
soybean lipoxygenase with modifications.31 One concentration (20 µL) of each compound
was mixed individually with 150 µL sodium phosphate buffer (pH = 7.4) containing (20 µL)
of 5-LOX enzyme and 60 µL of linoleic acid (3.5 mM), yielding a final volume of 250 µL.
The mixture was incubated at 25°C for 10 min, and the absorbance was determined at 234
nm. Nordihydroguaiaretic acid (NDGA) was used as positive control. The percentages of
enzyme activity were obtained at 100 µM. All measurements were performed in triplicate.
4.4. Cytotoxic activity
27

Cytotoxicity of synthesized compounds was estimated against two ovarian cancer cell lines
(IGROV and OVCAR) and colon cancer cell line (HCT-116) using the 3-(4,5-
dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.32 100 µL of each cells
at a concentration of 104 cells/wells were distributed in 96-well plates and maintained at 37°C
during 24 h in an incubator with 5% CO2. Then, 100 µL of each compounds (100 µM) diluted
on the RPMI-1640 medium were added and the mixture was incubated for 48 h at 37°C.
Then, cells were treated with 50 µL of MTT solution, prepared in phosphate buffered saline
(PBS), at a concentration of 1 mg/mL and incubated at 37°C during 40 min. After that, MTT
solution was absorbed and 50 µL of DMSO were added to dissolve insoluble formazan blue
crystals. Cell growth was estimated by the determination of optical density at 605 nm.
Doxorubicin and Tamoxifen were used as standard.
4.5. Molecule description
DFT is the most efficient way to calculate accurate and reliable electronic properties of
molecules. Once the 3D chemical structures of the molecules built and optimized in gas phase
using Amsterdam Density Functional(ADF) software,33 DFT calculations were performed
with the PBE (Perdew, Burke and Ernzerhof),34 GGA exchange-correlation functional
(Generalized Gradient Approximation) method and a TZP (triple zeta) basis set.35,36 From
these, 10 molecular descriptors were obtained: the energy of the highest occupied molecular
orbital (HOMO), the energy of the lowest unoccupied molecular orbital (LUMO), the
maximal (qmax) and minimal (qmin) atomic Mulliken charges, the dipole moment, the vertical
electronic affinity (A), the hardness (η=I-A where I is the vertical ionization potential), the
electronic chemical potential (μ=-(I+A)/2)), the nucleofugality (λN)and electrofugality (λE).
The results are presented in Table 1.
The physico-chemical properties of all flavonols derivatives have been assessed using
Molinspiration software23 are presented in Table 5. According to Lipinski’s rule of five, used
28

as a filter for drug-like properties to predict oral bioavailability, we describe the molecular
properties of a compound in order to estimate their pharmacokinetic parameters in the human
body, including their absorption, distribution, metabolism and excretion. Most ‘‘drug-like”
molecules have logP ≤5 that means these shows good permeability across cell membrane,
number of hydrogen bond acceptors ≤10 this measures molecular flexibility, molecular
weight ≤500, polar surface area (TPSA) < 160 Ǻ2 which displayed to be a good descriptor
characterizing drug absorption37 and number of hydrogen bond donor’s ≤5 is the sum of OHs
and NHs.38 Molecules violating more than one of these rules decrease the activity and
selectivity of a likely drug candidate and therefore make it unlikely orally active in humans.
4.6. Statistical analysis
Data from the experiments were subjected to analysis of variance (ANOVA) using SPSS 16.0
for Windows (SPSS Inc. Chicago, IL, USA). The inhibition data relative to 15-lipoxygenase
inhibition and cytotoxic activity have been transformed using arcsin- square root (arcsin x)
transformation before ANOVA. Means were separated at the 5% significance level by a least
significant difference test (Student’s test).
Linear Discriminant Analysis (LDA) is a multivariate technique first developed by Fisher
widely used for pattern classification.39 LDA allows determining which variables discriminate
between several naturally occurring groups. Here, for each measured biological activity (15-
lipoxygenase inhibitory, HCT-116, IGROV and OVCAR), the molecules were labeled so as
to describe three different classes relatively balanced in size defined by taking into account
the range of variation and the whole values measured for each activity (Table 2). LDA was
used to investigate the possible classification of the synthesized molecules in these three
categories from the available molecular descriptors. XLSTAT software was used here for
LDA calculations. More precisely, LDA models were determined by using a stepwise
(forward) method: the initial variables used to compute the linear discriminant functions were
29