7-Hydroxy-benzopyran-4-one derivatives: A novel pharmacophore of peroxisome proliferator-activated receptor α and -γ (PPARα and γ) dual agonists

Article abstract of DOI:10.1021/jm900964r

Design, synthesis, and in vitro bioevaluation of a new class of potential dual PPARα and γ agonists discovered through a structure-driven design paradigm are described. The 7-hydroxy-benzopyran-4-one moiety (includes flavones, flavanones, and isoflavones) is the key pharmacophore of these novel molecules, exhibiting similarity to the core structure of both fibrates and thiazolidinediones. New lead PPAR ligands were identified from "natraceuticals" and synthetic analogues. In total, 77 molecules, including chalcones, flavones, flavanones, isoflavones, and pyrazole derivatives, were screened and structure-activity relationship studies of the dual agonists undertaken. Compounds 68, 70, 72, and 76 were identified as novel and potent dual PPARα and γ agonists. These novel molecules may have the potential to be the future leads in PPAR-related disorders, including type II diabetes mellitus and metabolic syndrome. 2009 American Chemical Society.

Full text of DOI:10.1021/jm900964r

J. Med. Chem. 2009, 52, 6835–6850 6835
DOI: 10.1021/jm900964r
7-Hydroxy-benzopyran-4-one Derivatives: A Novel Pharmacophore of Peroxisome
Proliferator-Activated Receptor r and -γ (PPARr and γ) Dual Agonists
Azadeh Matin,† Navnath Gavande,† Moon S. Kim, Nancy X. Yang, Noeris K. Salam,‡ Jane R. Hanrahan,
Rebecca H. Roubin, and David E. Hibbs*
Faculty of Pharmacy, The University of Sydney, NSW 2006, Sydney, Australia. †These two authors contributed equally.
‡ Current contact address: Schrodinger, Inc., 120 West 45th Street, 29th Floor, New York, New York 10036.
¨
Received June 30, 2009
Design, synthesis, and in vitro bioevaluation of a new class of potential dual PPARR and γ agonists
discovered through a structure-driven design paradigm are described. The 7-hydroxy-benzopyran-
4-one moiety (includes flavones, flavanones, and isoflavones) is the key pharmacophore of these novel
molecules, exhibiting similarity to the core structure of both fibrates and thiazolidinediones. New lead
PPAR ligands were identified from “natraceuticals” and synthetic analogues. In total, 77 molecules,
including chalcones, flavones, flavanones, isoflavones, and pyrazole derivatives, were screened and
structure-activity relationship studies of the dual agonists undertaken. Compounds 68, 70, 72, and 76
were identified as novel and potent dual PPARR and γ agonists. These novel molecules may have the
potential to be the future leads in PPAR-related disorders, including type II diabetes mellitus and
metabolic syndrome.
Introduction
(Figure 1) act by lowering triglycerides and elevating HDL
and are most effective in the treatment of hypertriglycer-
idemia.14
Peroxisome proliferator-activated receptors (PPARsa) are
nuclear receptors that function as ligand activated transcrip-
tion factors regulating the expression of specific genes.1-3
PPARs are known to act via two distinct prominent mechan-
isms, transrepression and transactivation. The former is a
DNA independent mechanism and is associated with disrup-
tion of other transcription factor pathways while the latter is
DNA dependent and involves binding to PPAR response
element (PPRE) of the target genes.2,4
PPARs are implicated in the pathology of various
disease states including type II diabetes,5 obesity,6 hyper-
lipidemia,7 cardiovascular disease,8 neoplastic diseases
and tumors,9 inflammatory conditions,10 and neurode-
generative diseases.11 PPARs are thus the target of nu-
merous drug design and development efforts and the
significant role of PPARs in regulation of inflammatory
responses, development, cellular differentiation, glucose
homeostasis, and lipid metabolism is the subject of many
studies.12
Three PPAR isoforms are known to date, PPARR, γ,
and β/δ.10,13 PPARR is mainly found in liver, kidney,
heart, muscle, and adipose tissue and plays a critical role
in fatty acid oxidation and lipoprotein metabolism.13,14
PPARR is the molecular target for the fibrate class of
drugs,15 fenofibrate 1, clofibrate, bezafibrate, and similar
compounds such as 4-chloro-6-(2,3-xylidino)-2-pyrimidi-
nylthioacetic acid (WY-14643)16 2. These PPARR agonists
PPARγ is predominately expressed in adipose tissue,
macrophages, monocytes, and intestinal cells as well as
skeletal muscle and endothelium. The significant role
of PPARγ in lipid metabolism, adipogenesis, glucose
homeostasis, and insulin sensitization is well documented.
PPARγ agonists such as thiazolidinediones (TZDs, e.g.
rosiglitazone 3) and L-tyrosine analogues have been used
in clinical practice to treat type II diabetes for many years
and have been shown to lower blood glucose levels and
improve insulin sensitivity.17,18 However, despite their
excellent potencies, several of the known PPARγ agonists
(Figure 1) have presented unwanted adverse therapeutic
profiles such as fluid retention, weight gain, and cardiac
hypertrophy.14,17 Troglitazone, for example, was with-
drawn from therapeutic use due to liver toxicity and fargli-
tazar 5 failed to pass phase III clinical trials due to the
emergence of peripheral edema. Pioglitazone and rosiglita-
zone 3 are the two TZDs that are currently in clinical
practice despite being linked to controversial side effects
including an increased risk of cardiovascular related
death.15
In recent years, the concept of dual PPARR and γ agonists
has gained enormous attention.14,15 It is believed that such
dual agonists may exhibit enhanced effectiveness in treatment
of type II diabetes and metabolic syndrome, as these drugs
target hyperglycemia and insulin resistance in addition to the
associated lipid abnormalities. Moreover, fibrates are well-
known to alleviate weight gain and thus may reduce certain
side effects induced by PPARγ activation. To date a number
of dual agonists have been developed (Figure 1), including
farglitazar 5, ragaglitazar, tesaglitazar, and muraglitazar 6,
*To whom correspondence should be addressed. Phone: þ61 2
93516005. Fax: þ61 2 93514391. E-mail: davidh@pharm.usyd.edu.au.
a Abbreviations: PPAR peroxisome proliferator-activated receptor;
PPRE, peroxisome proliferator-activated receptor response element;
TZD, thiazolidinedione; HEK, human embryonic kidney.
r
2009 American Chemical Society
Published on Web 10/06/2009
pubs.acs.org/jmc

6836 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21
Matin et al.
Figure 3. Lead PPARγ agonists identified by virtual screening of a
Figure 1. PPAR agonists.
natural product library.1
Figure 2. Graphical illustration of the key pharmacophore concept.
Figure 4. General structure of the flavone, flavanone, isoflavone,
chalcone, and pyrazole derivatives.
which despite their potencies have failed the late stages of
clinical trials.4
Thus development of novel, efficacious, and yet safer
dual PPARR and γ agonists are of considerable thera-
peutic value. Herein we report the design, synthesis, and
in vitro bioevaluation of a new class of dual PPARR and -
γ agonists that are structurally distinct from fibrates and
TZDs.
Recent studies on biological evaluation revealed them to be
anticancer,19,20 antihyperglycemic,21 antifungal,22 anti-
viral,23 anti-inflammatory,24 antioxidant,25 and cardiovascular
agents.26 Although the skeleton of 7-hydroxy-benzopyran-
4-one pharmacophore plays an important role in biological
effects of flavonoid and isoflavonoid derivatives, the nature
of the peripheral substituents is also crucial. For example,
isoflavones containing amine-bearing side chain are potential
selective estrogen receptor modulators,27 while substitution of
the heterocyclic group of isoflavone pharmacophore enhanced
aromatase inhibitory activity.28 Recently, we have reported
ψ-baptigenin 70 (isoflavone, found in plants such as red clover)
and hesperidin 44 (flavanone glycoside that is mainly in citrus
fruit) as two new PPARγ agonists (Figure 3).1 This was
achieved via virtual screening of an in-house natural product
library consisting of 200 compounds extracted from botanical
sources.1
Results and Discussion
Pharmacophore Design. The key pharmacophore, 7-hy-
droxy-benzopyran-4-one moiety (includes flavones, flava-
nones, and isoflavones), was designed via a proposed
cyclization of 1,3-diaryl-2-propenones. 7-Hydroxy-benzo-
pyran-4-one exhibits a high resemblance to the core structure
of both fibrates and TZDs, while the key functional groups,
namely the phenyl moiety and the acidic group, lie a within
similar orientation and space (Figure 2).
In the search for new lead PPAR ligands that fit our key
pharmacophore, it was of great importance to explore
avenues that are showing much promise as potential treat-
ments of diabetes, most importantly “natraceuticals”, or
natural products derived from plant and herb sources.
Flavonoids and isoflavonoids are polyphenolic com-
pounds which have been found in plants and dietary com-
ponents such as fruits, vegetables, soybeans, and red wine.
Given that these two lead compounds fit our key pharma-
cophore perfectly, we investigated them and their analogues
(in total 77 molecules) further as potential dual PPARγ
and R agonists. This was achieved by initial screening of all
77 molecules for PPARγ agonist activity to highlight the
potent molecules, which were subsequently bioevaluated for

Article
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21 6837
Scheme 1a
trifluoroacetic anhydride and pyridine. The 7-O-ω-carboxy-
methyloxy derivative 103 of ψ-baptigenin was synthesized
according to the synthetic procedure depicted in Scheme 6.
The intermediate 97 was converted to the corresponding
isoflavone 100 via cyclization by treatment with acetic
anhydride, followed by base hydrolysis, affording 101. Sub-
sequent alkylation of 101 with ethyl 2-bromoacetate in the
presence of excess potassium carbonate in DMF yielded 102.
Base hydrolysis furnished compound 103.
Condensation of resorcinol with the appropriate phenyl-
a Reagents and conditions: (a) KOH, EtOH, rt, 24 h.
acetic acid in the presence of BF3 Et2O through the Friedel-
3
PPARR agonist activity to identify molecules with dual
activity. Assessed molecules consisted of chalcones, 7-hydroxy-
benzopyran-4-one (includes flavones, flavanones, and isofla-
vones and their glycosylated analogues) and pyrazole derivatives
including: (i) chalcones and hesperidin 44 related molecules with
various substituents, (ii) flavones, which are distinguished from
flavanones solely by the presence of the 2,3 double bond in the
chromone ring, (iii) ψ-baptigenin derivatives (isoflavones), as
well as (iv) pyrazole derivatives (Figure 4). The latter group is
quite distinct from the others. This was to examine the role of the
carbonyl group and the chromone ring on PPARγ agonist
activity.
Chemistry. The chalcones 7-11 were synthesized by base
catalyzed Claisen-Schmidt condensation29 of acetophe-
nones with appropriate benzaldehydes (Scheme 1).
Compounds 12-45 (95% purity or higher) were sourced
from the Sigma Aldrich or Indofine Chemical Company and
used as received (Table 1).
3-Iodo-7-(tetrahydropyran-2-yloxy)-benzopyran-4-one
49 (Scheme 2) was considered a key intermediate in the
synthesis of the isoflavones. This was due to the excellent
electrophilic properties of the iodo moiety as well as its
strategic position (next to the double bond), making it
an ideal substrate for palladium catalyzed Suzuki cou-
pling. The synthesis of this intermediate was achieved
from 2,4-dihydroxy acetophenone through a sequence of
reactions previously described.:30 selective protection
of the 4-hydroxyl by a THP ether, condensation with
N,N-dimethylformamide dimethylacetal (DMF-DMA)
to give 3-(dimethylamino)-20-hydroxyacrylophenone and
cyclization using I2 to furnish the corresponding iodoben-
zopyranone. Suzuki-Miyaura coupling of the intermedi-
ate with appropriate substituted boronic acids afforded
50-67. Subsequent THP ether cleavage of corresponding
isoflavones provided the target PPAR agonists 68-85
(Scheme 2).
Crafts acylation reaction33 afforded corresponding ketones
106 and 107 (Scheme 7). The ketone 106 was cyclized to
the trifluoromethyl-substituted isoflavone 108 by using tri-
fluoroacetic anhydride and pyridine. Furthermore, the
ketones 106 and 107 were cyclized to the corresponding
alkylated isoflavones 109 and 110, respectively, by using
Ac2O and K2CO3.
The SAR study was extended by incorporation of the
pyrazole fragment into the C-ring. Compounds 111-115
were prepared by nucleophilic attack of hydrazine at the
C(2)-atom of the corresponding isoflavones.34 Correspond-
ingly, we have synthesized novel 7-hydroxy-benzopyran-
4-one and pyrazole derivatives (50, 53-67, 71, 75, 77-79,
83-86, 98-99, 101, 103, 108, 109, 111-114) for biological
evaluation to develop a preliminary set of structure-activity
relationships.
Biological Evaluation. The compounds were screened for
in vitro PPAR agonist activity using the human embryonic
kidney (HEK) 293 cell line luciferase reporter gene assay as
described previously,35 with slight modifications. Commer-
cially available PPAR agonists, 2 and rosiglitazone 3, were
used as positive controls for PPARγ and R activity, respectively.
DMSO solution (0.1%) acted as the vehicle control.
Minimum PPAR fold activation obtained with the vehicle
control was defined as 1-fold activation. The results are
expressed as relative luciferase activity normalized to the
β-galactosidase signal (fold difference compared to vehicle
control). In total, 77 compounds were tested at various
concentrations. The molecules were initially evaluated for
PPARγ agonist activity, and compounds showing PPARγ
efficacy were then further investigated for PPARR activity.
The results are summarized in Tables 2-5.
From the chalcone series, five analogues were examined
(Table 2). Compound 10 demonstrated a similar PPARγactivity
(3.5-fold activation) to rosiglitazone 3 (4.2-fold activation) at
25 μM. The other chalcone analogues, however, were shown to
be less active. This correlates with the findings of Jung et al.36 and
highlights the importance of C-4 methoxyl group in improving
the PPARγ agonistic activity. In addition, our studies demon-
strate for the first time the role of C-3 methoxyl group in
enhancing the PPARγ agonistic activity.
From the flavone and flavanone series, 26 and 9 com-
pounds were examined, respectively (Table 3). Flavones
12-19 and 21 exhibited similar to 2-fold higher PPARγ
activity (5.0-8.9-fold activation) than the positive
control rosiglitazone 3 (4.2-fold activation) at 25 μM.
Flavones, gossypetin 29 and robinetin trimethyl ether
33, did not activate PPAR at the tested concentrations.
Most notably, the glycosylated compounds including
myricitrin 23, linarin 24, diosmin 25, neodiosmin 26,
rhoifolin 27, apiin 28, myricetin trimethyl ether 34, and
gossypin 36 also showed no PPAR activation at the tested
concentrations.
Compounds 86-88 were prepared by deprotection of the
methyl ether using BBr3/CH2Cl3 protocol,31 as depicted in
the Scheme 3.
The isoflavones 93 and 94 were obtained by electrophilic
substitution of the appropriate phenols with benzyl cyanides
(Houben-Hoesch reaction).32 Cyclization of the resultant
hydroxyketones to the isoflavones was achieved using DMF
as a 1-carbon electrophile in the presence of BF3 Et2O
3
(Scheme 4).
O-Methylation of ψ-baptigenin 70 with methyl iodide
generated 95 (Scheme 5).
The intermediate 97 obtained by the previously described
Houben-Hoesch reaction was used to generate compounds
98-103 (Scheme 6). This intermediate was cyclized to the
isoflavone 98 using DMF as a 1-carbon electrophile in the
presence of BF3 Et2O. The trifluoromethyl-substituted iso-
3
flavone 99 was prepared by cyclizing 97 in the presence of

6838 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21
Matin et al.
Table 1. Chemical Structures of Commercially Available Flavones and Flavanones
substitution
R8
0
0
0
0
names
R3
R5
R6
R7
R2
R3
R4
R5
(R3: OR; R: Rhamnoside)
12 (7,20-dihydroxyflavone)
13 (7,30-dihydroxyflavone)
14 (7,40-dihydroxyflavone)
15 (6,40-dihydroxyflavone)
16 (5,40-dihydroxyflavone)
17 (30,40-dihydroxyflavone)
18 (apigenin)
H
H
H
H
H
OH
H
H
H
H
H
H
H
H
OH
OH
OH
H
H
H
H
H
H
H
H
H
H
H
H
H
OH
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
OH
H
H
H
H
H
H
H
H
H
H
OR
H
OH
H
H
H
OH
OH
OH
OH
OH
OMe
OH
OMe
H
H
H
OH
OH
OH
OH
OH
OH
OH
OH
H
H
H
H
OH
OH
OH
OH
OH
OH
H
19 (acacetin)
20 (chrysoeriol)
H
OMe
OH
H
21 (diosmetin)
22 (chrysin)
23 (myricitrin)
OH
OH
(R7: OR; R: Rutinoside)
24 (linarin)
25 (diosmin)
H
H
OH
OH
H
H
OR
OR
H
H
H
H
H
H
OMe
OMe
H
OH
(R7: OR; R: Neohesperidoside)
26 (neodiosmin)
27 (rhoifolin)
H
H
OH
OH
H
H
OR
OR
H
H
H
H
H
H
OMe
OH
OH
H
(R7: OR; R: Apioglucoside)
OR
28 (apiin)
H
OH
H
H
H
H
OH
H
(R8: OR; R: Glucoside)
29 (gossypetin)
30 (kaempferol)
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
H
H
H
H
H
H
H
H
H
OH
OH
OH
OH
OH
OH
OH
OH
OH
H
H
H
H
H
H
H
H
H
OH
OH
OH
H
H
OH
H
31 (quercetin)
H
OH
H
32 (fisetin 3040-dimethyl ether)
33 (robinetin trimethyl ether)
34 (myricetin trimethyl ether)
35 (syringetin)
H
OMe
OMe
OMe
OMe
OH
OMe
OMe
OMe
OH
H
H
H
OMe
OMe
OMe
H
OH
OH
OH
H
H
OR
36 (gossypin)
OH
(R7: OR; R: Neohesperidoside)
37 (naringenin)
38 (hesperetin)
39 (naringin)
H
H
H
H
H
H
OH
OH
OH
OH
OH
OH
H
H
H
H
H
H
OH
OH
OR
OR
OR
OR
H
H
H
H
H
H
H
H
H
H
H
H
H
OH
OMe
OH
H
H
H
H
H
H
OH
H
40 (neohesperidin)
41 (neoeriocitrin)
42 (poncirin)
OH
OH
H
OMe
OH
OMe
(R7: OR; R: Rutinoside)
43 (narirutin)
44 (hesperidin)
H
H
OH
OH
H
H
OR
OR
H
H
H
H
H
OH
OH
OMe
H
H
(R7: OR; R: Glucoside)
OR
45 (naringeinin-7-O-glucoside)
H
OH
H
H
H
H
OH
H
Apigenin 18, chrysin 22, and kaempferol 30 exhibited
slightly lower PPARγ activation (Table 3) than that pre-
viously reported (8.13-, 5.6-, and 7.6-fold activation at
10 μM, respectively) using a different in vitro model
(mouse macrophage RAW264.7 cell line).37
(Table 3). This is in contrast to studies of Liang et al.,37 where
no PPARγ activation was observed for flavanones. The glyco-
sylated flavanones including naringin 39, neohesperidin 40,
neoeriocitrin 41, poncirin 42, and narirutin 43 did not activate
PPAR, except for naringeinin-7-O-glucoside 45, which exhibited
a slight PPARγ activation at 25 μM (1.8-fold activation). Our
result for naringin 39 correlates with the studies of Liang et al.37
From the flavanone family, only compounds 37 and 38
demonstrated weak to moderate PPARγ agonist activity

Article
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21 6839
Scheme 2a
a Reagents and conditions: (a) DHP, PPTS, DCM, rt for 4 h; (b) DMF-DMA, 95 °C for 3 h; (c) I2, pyridine, CHCl3, rt for 12 h; (d) ArB(OH)2,
10% Pd/C, Na2CO3, DME/H2O, 45 °C for 1-3 h; (e) p-TsOH, MeOH, THF, 60 °C for 1-2 h.
Scheme 3a
Scheme 4a
a Reagents and conditions: (a) BBr3, DCM, 0 °C to rt, 2-8 h.
From the isoflavone and pyrazole series, 34 derivatives
were examined (Table 4). Compounds 46-51, 53-55,
57-66, 89-92, 97, 100, 102, 104-107, and 109-110 were
used as intermediates to derive 7-hydroxy-benzopyran-4-one
analogues and therefore were not tested for PPAR activa-
tion. Compounds 79, 84, 85, 99, and 111 showed no PPAR
activation at the tested concentrations. Daidzein 87 (9.6-fold
activation) exhibited a substantially higher PPARγ activa-
tion compared to rosiglitazone 3 (4.2-fold activation) and
genistein 94 (3.4-fold activation) at 25 μM. This is higher
than the PPARγ activation in human endothelial cells by
daidzein 87 (2-fold activation) but comparable to PPARγ
activation by genistein 94.38
Compounds 68, 70, 72, and 76 (11.9, 12.1, 20.6 and 9.1-
fold activation, respectively) exhibited a substantially higher
PPARγ fold activation compared to rosiglitazone 3 (2.9-fold
activation) at 5 μM and N-(2-benzoylphenyl)-O-[2-(methyl-
2-pyridinylamino)ethyl]-L-tyrosine hydrochloride (GW1929)39
(2.7-fold activation) at 5 μM (Table 4 and Figure 5). At a
concentration of 25 μM, these compounds demonstrated
remarkable PPARγ efficacy, in particular compounds 68
and 72 exhibited over 100-fold PPARγ activation. To date,
rosiglitazone 3 has been considered the most efficacious
“full” PPARγ agonist. We hypothesis that, as rosiglitazone
3 is a synthetic PPARγ agonist and the biologically relevant
a Reagents and conditions: (a) 4-hydroxyphenyl acetonitrile, anhy-
drous HCl, ZnCl2-Et2O, then aq HCl, heat; (b) BF3.Et2O, DMF,
MeSO2Cl, 100 °C, 2 h.
Scheme 5a
a Reagents and conditions: (a) MeI, K2CO3, DMF, rt for 3 h.
natural PPARγ agonist remains elusive, our compounds
may resemble the natural full PPARγ agonists due to their
very high efficacy.
Furthermore, compounds 68, 70, 72, and 76 (EC50=18.86,
26.94, 15.38, and 22.29 μM, respectively) exhibited at least
nearly 2-fold more potency in activating PPARγ than the
positive control, rosiglitazone 3 (EC50 = 43.71 μM), as
shown in Table 5. The EC50 results obtained for rosiglita-
zone 3 vary from that reported in the literature.40 This is
most likely due to the different transactivation plasmid sys-
tems used in the assay, e.g., full-length hPPARγ and
tk-PPREx4-Luc plasmids used in our assays versus chime-
ric fusion protein GAL4-PPARγ-LBD and GAL4-Luc

6840 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21
Matin et al.
Scheme 6a
a Reagents and conditions: (a) 4-ethylresorcinol, anhyd HCl, ZnCl2-Et2O, then aq HCl, heat; (b) BF3 Et2O, DMF, PCl5, 60-70 °C for 1-2 h;
3
(c) (CF3CO)2O, pyridine, 0 °C to rt for 12 h; (d) Ac2O, TEA, 120-130 °C for 8 h; (e) NaOH, 1 h; (f) Br-CH2COOEt, K2CO3, DMF, 90 °C for 8 h;
(g) NaOH, 2 h.
Scheme 7a
a Reagents and conditions: (a) resorcinol, BF3 Et2O, 90 °C for 90 min; (b) (CF3CO)2O, pyridine, 0 °C to rt for 12 h; (c) Ac2O, K2CO3, DMF, 115 °C
3
for 2 h; (d) hydrazine hydrate, EtOH, 70 °C for 8 h.
plasmids. The transactivation plasmids used in our assay
more closely correspond to the actual in vivo cellular trans-
activation.
The PPARγ activating flavones, flavanones, and isofla-
vones were subsequently tested against PPARR. Interest-
ingly, they all demonstrated higher fold activity than the

Article
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21 6841
Table 2. In Vitro PPARγ Fold Activation of Chalcones 7-11
Table 3. In Vitro PPARγ Fold Activation by 7-Hydroxy-benzopyran-
4-one Derivatives (Flavone and Flavanone Analogues) 12-22, 30-32,
35, and 37-38
PPARγ fold activation (SEM)a
name
3 (rosiglitazone)
5 μM
25 μM
2.9(0.17)
2.7(0.35)
2.0(0.16)
1.9(0.44)
1.3(0.02)
1.7(0.46)
2.5(0.30)
1.6(0.53)
1.9(0.16)
2.0(0.23)
1.3(0.46)
2.5(0.37)
1.3(0.08)
NA
4.2(0.29)
4
PPARγ fold activation
(SEM)a
12 (7,20-dihydroxyflavone)
13 (7,30-dihydroxyflavone)
14 (7,40-dihydroxyflavone)
15 (6,40-dihydroxyflavone)
16 (5,40-dihydroxyflavone)
17 (30,40-dihydroxyflavone)
18 (apigenin)
6.8(0.91)
6.3(0.47)
5.0(0.34)
5.0(0.45)
8.9(0.75)
5.0(0.66)
5.4(0.53)
7.7(0.48)
2.2(0.34)
7.3(0.25)
4.0(0.44)
3.5(0.32)
1.3(0.22)
2.4(0.14)
1.2(0.05)
1.7(0.12)
3.8(0.08)
compd
5 μM
25 μM
3 (rosiglitazone)
2.9(0.17)
2.7(0.35)
1.1(0.08)
1.25(0.15)
1.15(0.07)
4.2(0.29)
4
7 (20,40-dihydroxy-2-methoxychalcone)
8 (20,40-dihydroxy-4-hydroxychalcone)
9 (20,40-dihydroxy-3-methoxychalcone)
1.1(0.04)
1.3(0.09)
2.1(0.12)
3.5(0.12)
2.6(0.18)
19 (acacetin)
20 (chrysoeriol)
10 (20,40-dihydroxy-3,4-dimethoxychalcone) 1.7(0.13)
11 (20,40-dihydroxy-4-methoxychalcone)
1.8(0.11)
21 (diosmetin)
22 (chrysin)
a Fold activation compared to vehicle control, where the mean
relative luciferase activity is normalized to the β-galactosidase signal
of two experiments performed in triplicate.
30 (kaempferol)
31 (quercetin)
32 (fisetin 3040-dimethyl ether)
35 (syringetin)
1.2(0.12)
1.1(0.11)
1.9(0.15)
1.0(0.07)
1.5(0.10)
positive controls fenofibrate 1 (1.3-fold activation) and 2
(1.7-fold activation) at 25 μM (Table 6).
37 (naringenin)
38 (hesperetin)
a Fold activation compared to vehicle control, where the mean
relative luciferase activity is normalized to the β-galactosidase signal
of two experiments performed in triplicate. NA: No PPAR activation
was observed at the tested concentration.
Most notably, as illustrated in Figure 6, compounds 68,
70, 72, and 76 demonstrated a significant dual activity, as
evidenced by their additional PPARR activity (25.3-, 11.7-,
28.7-, and 43.0-fold activation, respectively) at 40 μM. To
date, 2 has been considered the most efficacious “full”
PPARR agonist. Similar to the PPARγ results, we hypoth-
esis that, as 2 is a synthetic PPARR agonist and the biologi-
cally relevant natural PPARR agonist remains elusive, our
compounds may resemble the natural full PPARR agonists
due to their high efficacy.
demonstrated a cell viability of greater than 90% only at
0.1 μM. Molecules 68, 70, 72, and 76 all exhibited a cell
viability of more than 67% at 50 μM, however, fenofibrate 1
showed greater toxicity with a decrease in cell viability to
38% at the same concentration.
Compounds 68, 70, 72, and 76 (EC50=24.55, 8.90, 33.13,
and 23.10 μM, respectively) exhibited similar or higher
potency in activating PPARR than the positive controls
fenofibrate 1 (EC50 =33.51 μM) and 2 (EC50 =23.33 μM)
as shown in Table 5. Compound 68 and 76 showed similar
potency for both PPARR and PPARγ. Compound 70 ex-
hibited more potent PPARR activation than PPARγ activa-
tion. In contrast, compound 72 was a more potent PPARγ
activator than a PPARR activator. These four molecules
were therefore identified as the most potent dual PPARR and
γ agonists evaluated.
To ensure that these dual active compounds (68, 70, 72, and
76) were nontoxic to HEK 293 cell line, cytotoxicity profiles
were investigated at various concentrations (0-100 μM) and
compared to the cytotoxicity of fenofibrate 1, rosiglitazone 3,
and 4.
Compared to the commercially available PPARγ agonists
rosiglitazone 3 and 4, as illustrated in Figure 7, ψ-baptigenin
70 and compound 76 exhibited a cell viability of greater than
90% at 10 μM (comparable to 4), while compound 68
showed a cell viability of greater than 80% at 10 μM
(comparable to rosiglitazone 3). Furthermore, ψ-baptigenin
70 and compound 76 maintained a cell viability of greater
than 60% even at 100 μM, significantly less toxic than
rosiglitazone 3 and 4 (46% and 33%, respectively). These
ψ-baptigenin 70 results are comparable to our previous
studies in macrophage THP-1 cell line.1
In Vitro SAR Studies of Chalcones, 7-Hydroxy-benzopyran-
4-one, and Pyrazole Derivatives. We have recently reported the
potent in vitro PPARγ agonist activity of hesperidin 44 and
ψ-baptigenin 70. After examining the virtual screening, in-
duced-fit docking and biological data, it became evident that
in addition to the B ring required for hydrophobic interac-
tions, such as π π stacking, with residues Phe282, Phe363,
3 3 3
and Phe360 of the PPARγ protein (Figure 8), all of the active
flavonoids also possessed a hydroxyl at the 7-position, allow-
ing hydrogen bond interactions with the residues Ser289,
His323, and Tyr479.1 In continuation of our efforts, this led
us to further expand the structure-activity relationships to
include the structural requirements for dual PPARγ and
PPARR agonist activity.
In the chalcone series, introduction of a methoxyl group
in positions C-3 and C-4 was shown to increase PPARγ
agonist activity. This is highlighted in Table 2, as compound
10 (3, 4-dimethoxyl substituted chalcone) was found to be
more efficacious than compounds 9 and 11 (3-methoxyl
and 4-methoxyl substituted chalcones, respectively). This
demonstrates the importance of C-3 and C-4 methoxyl
groups in enhancing the PPARγ agonist activity.
The lack of PPARγ activity of flavanones indicates
that the planar structure of flavones and isoflavones is
a requirement for both PPARR and PPARγ agonist activity.
In the case of PPARγ, hydroxyl substitution of both flavones
and isoflavones is well tolerated at the 5-, 6-, and 7-position
of the A-ring, with compounds 12-22 and most isoflavones
exhibiting agonist activity at these receptors. However,
the 7-hydroxy substituent substantially increases activity
at PPARR receptors compared to substitution at other
Compared to the commercially available PPARR agonist
fenofibrate 1, as shown in Figure 7, ψ-baptigenin 70
and compound 76 exhibited less toxicity with a cell viabi-
lity of greater than 90% at 10 μM, while fenofibrate 1

6842 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21
Matin et al.
Table 4. In Vitro PPARγ Fold Activation by 7-Hydroxy-benzopyran-4-one (Isoflavones) and Pyrazole Derivatives
PPARγ fold activation (SEM)a
5 μM 25 μM
2.9(0.17) 4.2(0.29)
compd
3 (rosiglitazone)
4
2.7(0.35)
3.4(0.24)
1.4(0.08)
1.0(0.12)
11.9(0.56)
4.6(0.27)
12.1(0.14)
4.7(0.34)
20.6(2.54)
2.0(0.07)
7.1(0.95)
2.9(0.54)
9.1(0.85)
2.3(0.48)
1.5(0.08)
NA
52 (30,40-methylenedioxy-7-(tetrahydropyran-2-yloxy)isoflavone)
56 (3-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-(tetrahydropyran-2-yloxy)isoflavone)
67 (30,40,50-trimethoxy-7-(tetrahydropyran-2-yloxy)isoflavone)
68 (30,50-dimethoxy-7-hydroxyisoflavone)
9.4(0.73)
2.0(0.15)
2.3(0.15)
116.3(2.21)
12.8(0.32)
38.5(1.17)
4.4(0.39)
147.8(4.21)
10.5(1.05)
11.3(0.78)
13.8(1.29)
57.5(2.57)
7.5(0.94)
1.4(0.05)
2.6(0.51)
4.1(0.17)
1.6(0.14)
2.1(0.07)
7.4(0.95)
9.6(1.24)
7.5(0.87)
4.4(0.98)
3.4(0.35)
25.2(1.54)
12.7(1.08)
5.3(0.94)
2.3(0.11)
3.0(0.54)
1.7(0.10)
3.9(0.53)
5.3(1.24)
2.2(0.18)
69 (40-methoxy-7-hydroxyisoflavone)
70 (ψ-baptigenin)
71 (40-trifluoromethyl-7-hydroxyisoflavone)
72 (40-fluoro-7-hydroxyisoflavone)
73 (30,40-dimethoxy-7-hydroxyisoflavone)
74 (3-(2,3-dihydro-1,4-benzodioxin-6-yl)-7-hydroxyisoflavone)
75 (20,40-difluoro-7-hydroxyisoflavone)
76 (30-methoxy-7-hydroxyisoflavone)
77 (20-methoxy-30,50-difluoro-7-hydroxyisoflavone)
78 (30,40,50-trifluoro-7-hydroxyisoflavone)
80 (40-chloro-7-hydroxyisoflavone)
81 (30-fluoro-7-hydroxyisoflavone)
1.8(0.14)
1.0(0.06)
1.8(0.12)
2.5(0.25)
1.2(0.17)
1.8(0.08)
2.3(0.87)
2.0(0.07)
8.7(0.97)
5.3(0.57)
1.25(0.08)
2.2(0.16)
1.75(0.34)
1.7(0.18)
2.25(0.72)
2.2(0.05)
2.4(0.27)
82 (20-Methoxy-7-hydroxyisoflavone)
83 (30-trifluoromethoxy-7-hydroxyisoflavone)
86 (30,50,7-trihydroxyisoflavone)
87 (daidzein)
88 (30,40,7-trihydroxyisoflavone)
93 (40,6,7,-trihydroxyisoflavone)
94 (genistein)
95 (7-methoxy-ψ-baptigenin)
98 (30,40-methylenedioxy)-6-ethyl-7-hydroxyisoflavone)
101 (30,40-methylenedioxy-2-methyl-6-ethyl-7-hydroxyisoflavone)
103 (2-(3-(benzo[d][1,3]dioxol-5-yl)-6-ethyl-2-methyl-4-oxo-4H-chromen-7-yloxy)acetic acid)
108 (40-fluoro-2-trifluoromethyl-7-hydroxyisoflavone)
112 (3-(2,4-dihydroxyphenyl)-4-(4-fluorophenyl)-1H-pyrazole)
113 (3-(2,4-dihydroxyphenyl)-4-(4-fluorophenyl)-5-trifluoromethyl-1H-pyrazole)
114 (3-(2,4-dihydroxyphenyl)-4-(4-fluorophenyl)-5-methyl-1H-pyrazole)
115 (3-(2,4-dihydroxyphenyl)-4-(4-methoxyphenyl)-5-methyl-1H-pyrazole)
a Fold activation compared to vehicle control, where the mean relative luciferase activity is normalized to the β-galactosidase signal of two
experiments performed in triplicate. NA: no activation was observed at the tested concentration.
Table 5. In Vitro Transactivation Activity Profile of Isoflavone Deri-
vatives
transactivation EC50
(μM, SEM)a
compd
hPPARγ
hPPARR
1 (fenofibrate)
2
3 (rosiglitazone)
33.51(1.02)
23.33(1.07)
43.71(1.08)
18.86(1.04)
26.94(1.08)
15.38(1.02)
22.29(1.05)
68 (30,50-dimethoxy-7-hydroxyisoflavone)
24.55(1.06)
8.90(1.10)
33.13(1.05)
23.10(1.04)
70 (psi-baptigenin)
72 (40-fluoro-7-hydroxyisoflavone)
76 (30-methoxy-7-hydroxyisoflavone)
a EC50 values for PPARγ and R agonist activity were calculated as the
concentration of the test ligand (μM) required for the half-maximal fold
induction of luciferase activity. Data shown are means (SEM) from three
experiments for each treatment.
Figure 5. PPARγ luciferase reporter gene activation of the most
efficacious isoflavone derivatives (5 and 25 μM) compared to the
positive control rosiglitazone 3 and 4. All values are expressed as
fold activation compared to DMSO vehicle control, where
the relative luciferase activity is normalized to the β-galactosi-
dase signal, mean ( SEM of two experiments performed in
triplicate.
positions of the A-ring. Changing the 7-hydroxyl group of
the ψ-baptigenin 70 to the 7-OTHP (52) or 7-methoxyl group
(95) is tolerated, however PPARγ activation was reduced
compared to 70. Introduction of alkyl substituents at the C-6
position of the A-ring (98) or the C-2 position of the C-ring
(101) markedly reduced PPARγ agonist activity compared
to the parent compounds 70 and 72, respectively.
0
0
Introduction of alkoxy/alkyl hydrophobic substitutions at
the R2 , R3 , R4 , or R5 positions of the isoflavone B-r0ing
showed that the presence of a H-bond acceptor on the R3 or
R5 and R4 positions results in significantly higher PPARR
and γ agonist activities, with the substituent position
and H-bond acceptor capability determining activity.
0
0
0
0

Article
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21 6843
Table 6. In Vitro PPARR Fold Activation of Flavones, Flavanones,
and Isoflavones
PPARR fold activation
(SEM)a
compd
25 μM
40 μM
1 (fenofibrate)
1.3(0.15)
1.7(0.17)
3.6(0.27)
8.2(0.98)
1.5(0.08)
2.6(0.11)
2.4(0.21)
2.8(0.15)
2.0(0.14)
2.3(0.31)
1.1(0.07)
2.8(0.16)
3.4(0.44)
1.8(0.12)
1.2(0.09)
1.9(0.25)
2.5(0.34)
2
12 (7,20-dihydroxyflavone)
13 (7,30-dihydroxyflavone)
14 (7,40-dihydroxyflavone)
15 (6,40-dihydroxyflavone)
16 (5,40-dihydroxyflavone)
17 (30,40-dihydroxyflavone)
18 (apigenin)
4.9(0.41)
14.8(0.74)
2.6(0.17)
3.5(0.15)
3.7(0.35)
7.7(1.07)
2.3(0.22)
5.2(0.95)
1.3(0.10)
3.8(0.13)
5.3(0.74)
2.6(0.15)
1.7(0.11)
2.0(0.15)
3.3(0.12)
Figure 7. Cytotoxicity profile of compounds 68, 70, 72, 76, and
PPAR agonists fenofibrate 1, rosiglitazone 3, and 4. Cell viability
was determined using the CellTiter96 Aqueous One solution cell
proliferation assay. The results are expressed as % relative cell
viability compared to DMSO vehicle control. All values are mean (
SEM of two experiments performed in quadruplicate.
19 (acacetin)
20 (chrysoeriol)
21 (diosmetin)
22 (chrysin)
30 (kaempferol)
37 (naringenin)
38 (hesperetin)
56 (3-(2,3-dihydro-
1,4-benzodioxin-6-yl)-
7-(tetrahydropyran-2-yloxy)isoflavone)
68 (30,50-dimethoxy-7-hydroxyisoflavone)
69 (40-methoxy-7-hydroxyisoflavone)
70 (ψ-baptigenin)
4.8(0.57)
7.5(0.52)
5.6(0.95)
8.6(0.83)
16.5(0.76)
6.2(0.93)
1.8(0.12)
2.2(0.07)
25.3(1.37)
7.8(0.43)
11.7(1.29)
28.7(1.85)
43.0(1.49)
13.4(1.28)
4.0(0.38)
2.4(0.13)
72 (40-fluoro-7-hydroxyisoflavone)
76 (30-methoxy-7-hydroxyisoflavone)
87 (daidzein)
93 (40,6,7,-trihydroxyisoflavone)
95 (7-methoxy-ψ-baptigenin)
a Fold activation compared to vehicle control, where the mean
relative luciferase activity is normalized to the β-galactosidase signal
of two experiments performed in triplicate.
Figure 8. Two-dimensional schematic interactions of ψ-baptigenin
70 in the LBD of PPAR-γ.1
drugs for PPARγ and PPARR, respectively, compounds 68,
70, 72, and 76 were 100 times more efficacious. A hydroxyl
group in the C-7 position was shown to be vital for PPAR
activity. The 40-fluoro (72) exhibited the highest potency for
PPARγ, whereas the 30,40-methylenedioxy group (70) was
found to be the most potent PPARR activator. The methoxyl
substituents at positions 30,50 (68) or 30 (76) were found to
exhibit similar potency for both PPARR and PPARγ. Lower
PPARγ activation was observed for compounds 74, 77-78,
and 84-85, indicating that multiple substituents
on the B-ring resulting in increased steric bulk reduces
the PPARγ activation. Typical PPARR and PPARγ dual
agonists usually have a carboxylic acid in a position equiva-
lent to the C7 position of the isoflavone. Disappointingly,
replacing the 7-OH group by a carboxylic acid moiety
resulted in a decrease in activity. A similar decrease in
activity was also reported by Guo et al.41 in the HepG2 cell
line in vitro model for CM108, a flavone derivative with
6,7-phosporothiolate moiety.
We then extended the SARs of lead compounds 70 and
72 by incorporation of the pyrazole fragment (Figure 4) into
the C-ring (112-115). We were surprised to find that we
were also able to see PPARγ activity from the novel pyrazole
scaffold, albeit considerably weaker than the activity seen
with the parent isoflavone, demonstrating the importance
of the 7-hydroxy-benzopyran-4-one scaffold. Substitution
of the 5-position of the pyrazole scaffold with a methyl
or trifluormethyl resulted in increased PPARγ activity
(Table 4).
Figure 6. PPARR luciferase reporter gene activation of isoflavone
derivatives with considerable PPARγ activity compared to the
PPARR positive control fenofibrate 1 and 2 at 25 μM. All values
are expressed as fold activation compared to DMSO vehicle control,
where the relative luciferase activity is normalized to the β-galacto-
sidase signal, mean ( SEM of two experiments performed in
triplicate.
Compounds 68 (30,50-dimethoxy), ψ-baptigenin 70 (30,40-
methylenedioxy), 72 (40-fluoro), and 76 (30-methoxy) were
found to be potent dual PPARR and PPARγ agonists.
Interestingly, the 40-fluoro (72) exhibited the highest activity
at PPARγ receptors, whereas compound 76 demonstrated
the highest activity at PPARR receptors. When compared to
2 and rosiglitazone 3, the two most widely used reference

6844 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21
Matin et al.
The key SAR trends from this study are the following:
(i) the 7-hydroxy-benzopyran-4-one scaffold and its orienta-
tion are an important determinant for both PPARR and
γ activity, with the planar isoflavone skeleton resulting in
higher activity, (ii) a hydroxyl group in the C-7 position is
crucial for PPARR and γ activity, (iii) H-bond acceptors at
the 30-position and 40-position are important for activity at
PPARR and PPARγ, respectively, (iv) increased steric bulk
of the isoflavone B-ring results in decreased PPAR activity,
(v) a fluoro group at position 40 is selective for PPARγ,
(vi) 30,40-methylenedioxy group is selective for PPARR, and
(vii) methoxy group at positions 30 or 30,50 is selective for both
PPARR and PPARγ.
concentration giving 50% of maximal observed activity. The
EC50 values were calculated via nonlinear regression using
GraphPad PRISM 5.02 (GraphPad software San Diego, CA).
The results are expressed as means ( SEM.
General Procedure for the Synthesis of the 1,3-Diaryl-2-Pro-
penones or Chalcones (7-11). 20,40-Dihydroxy-2-methoxychal-
cone (7). 2,4-Dihydroxyacetophenone (500 mg, 1 mmol) in
EtOH (3 mL) was treated with KOH (184 mg, 1 mmol) under
magnetically stirred condition for 10 min at room temperature,
followed by addition of 2-methoxybenzaldehyde (447 mg,
1 mmol). The mixture was stirred magnetically for 24 h at room
temperature. After the completion of the reaction, a yellow
precipitate was formed and this served as indicator for monitor-
ing the reaction visually. MeOH was removed under reduced
pressure. The residue was diluted with water (5 mL), neutralized
with 2% aq HCl, and extracted with EtOAc (3 ꢀ 20 mL). The
combined EtOAc extracts were washed with brine solution
(5 mL), dried (Na2SO4), and concentrated under reduced pres-
sure. Purification of crude product by flash chromatography
(40% EtOAc/hexane) gave 7 (284 mg, 32%) as a yellow solid. 1H
NMR (300 MHz, acetone-d6): δ 12.90 (s, 1H), 8.12 (d, 1H, J=8.3
Hz), 7.90 (d, 1H, J = 15.2 Hz), 7.72 (d, 1H, J = 15.1 Hz),
7.56-6.60 (m, 6H), 3.97 (s, 3H). MS (ESI) m/z=271.07 [M þ 1].
Compounds 8-11 were made using the same procedure as for
the preparation of compound 7 using appropriate starting
materials.
Conclusion
We have discovered 7-hydroxy-benzopyran-4-one deriva-
tives as the novel template for potential dual PPARR and
γ agonists. Systematic structure-driven design led to the
discovery of compounds 68, 70, 72, and 76 as the most potent
dual PPARR and γ agonists compared to commercially
available positive controls 2 and rosiglitazone 3. These iso-
flavones may havethe potentialtobe the future leadsin PPAR
related disorders, including type II diabetes mellitus and
metabolic syndrome. Additionally these compound exhibited
significantly lower cytotoxicity than 2 and rosiglitazone 3.
This study also demonstrates the potential of structure-based
drug design to fine-tune the relative activities at the different
PPAR receptor subtypes to develop ligands with reduced
toxicities. In particular, PPAR-δ is highly expressed in meta-
bolic tissues such as skeletal muscle (including cardiac muscle)
and brown adipose tissue (recently demonstrated in humans),
where it plays a significant role in oxidative lipid metabolism
and glucose homeostasis. In future studies, it might be useful
to generate PPAR pan-agonists or PPARγ/δ dual agonists in
order to combine antidiabetic and antiobesity effects while
ameliorating cardiac toxicity. Further in vivo pharmacologi-
cal evaluation of lead compounds is underway.
20,40-Dihydroxy-4-hydroxychalcone (8). Yield 41%; pale-yel-
low solid. 1H NMR (300 MHz, acetone-d6): δ 12.40 (s, 1H), 8.98
(s, 1H), 8.03 (s, 1H), 7.86 (d, 1H, J=15.1 Hz), 7.70 (d, 1H, J=
15.1 Hz), 7.52 (d, 1H, J=3.0 Hz), 7.05 (dd, 1H, J=3.0, 8.6 Hz),
6.91 (d, 2H, J=8.6 Hz), 6.79 (d, 1H, J=8.6 Hz). MS (ESI) m/z=
257.18 [M þ 1].
20,40-Dihydroxy-3-methoxychalcone (9). Yield 36%; pale-yel-
low solid. 1H NMR (300 MHz, acetone-d6): δ 12.80 (s, 1H), 8.08
(d, 1H, J=8.2 Hz), 7.88 (d, 1H, J=15.1 Hz), 7.68 (d, 1H, J=15.1
Hz), 7.52-6.50 (m, 6H), 3.91 (s, 3H). MS (ESI) m/z=271.09
[M þ 1].
20,40-Dihydroxy-3,4-dimethoxychalcone (10). Yield 38%; yel-
1
low plates. H NMR (acetone-d6, 300 MHz): δ 12.98 (s, 1H),
8.08 (d, 1H, J=8.1 Hz), 7.88 (d, 1H, J=15.1 Hz), 7.68 (d, 1H, J=
15.1 Hz), 7.52 (d, 1H, J=8.1 Hz), 7.01 (dd, 1H, J=2.1, 8.1 Hz),
7.26 (d, 1H, J=2.1 Hz), 6.36 (d, 1H, J=2.1 Hz), 6.44 (dd, 1H,
J=2.1, 8.4 Hz), 3.87 (s, 3H), 3.85 (s, 3H). MS (ESI) m/z=301.28
[M þ 1].
Experimental Section
20,40-Dihydroxy-4-methoxychalcone (11). Yield 45%; yellow
needles. 1H NMR (300 MHz, acetone-d6): δ 13.22 (s, 1H), 8.12
(d, 1H, J=8.7 Hz), 7.80 (d, 1H, J=15.3 Hz), 7.70 (d, 1H, J=15.3
Hz), 7.49 (d, 2H, J=8.7 Hz), 7.01 (d, 2H, J=8.7 Hz), 6.36 (1H, d,
J=2.1 Hz), 6.46 (dd, 1H, J=2.1, 8.7 Hz), 3.84 (s, 3H). MS (ESI)
m/z=271.05 [M þ 1].
All glass apparatus were oven-dried prior to use. All chemicals
used were purchased from Aldrich Chemical Co. Ltd. (St Louis,
MO) unless otherwise stated and were of highest commercially
available purity. Compounds 12-45 (95% purity or higher) were
purchasedfrom Sigma AldrichandIndofine Chemical Company,
USA. All solvents were distilled by standard techniques prior to
use. Where stated, reactions were performed under an inert
atmosphere of nitrogen. 1H NMR spectra were recorded at
300 MHz using a Varian (Palo Alto, CA) Gemini 300 spectrometer.
Chemical shifts (δ) are quoted in parts per million (ppm),
referenced externally to tetramethyl silane at 0 ppm. 13C NMR
spectra were recorded at 100 MHz using a Varian (USA) 400 MI
spectrometer. Chemical shifts (δ) are quoted in ppm, referenced
internally to CDCl3 at 77.0 ppm. All coupling constants (J) are
given in hertz. Low and high resolution electrospray ionization
(ESI) MS was carried out using a Bruker (USA) Daltronics
BioApexII with a 7T superconducting magnet and an analytical
ESI source. All synthetic compounds for in vitro studies were
g98% purity as determined by combustion analyses, which were
performed at the Research School of Chemistry, Australian
National University, Canberra. Thin layer chromatography
was performed on Merck aluminum backed plates, precoated
with silica (0.2 mm, 60F254), which were developed using one of
the following techniques: UV fluorescence (254 nm) and iodine
vapors. Flash chromatography was performed on silica gel
(Merck silica gel 60H, particle size 5-40 μm). The EC50 is the
General Procedure for the Synthesis of 3-Iodo-7-(tetrahydro-
pyran-2-yloxy)-benzopyran-4-one (49). A solution of DHP (3,4-
dihydro-2H-pyran) (18 mL, 3.0 equiv) in CH2Cl2 (100 mL) was
added dropwise to a solution of 2,4-dihydroxy acetophenone, 46
(10 g, 3.0 equiv), and PPTS (pyridinium-p-toluenesulfonate)
(600 mg) at room temperature. The resulting mixture was stirred
for 4 h at room temperature and then washed with saturated aq
NaHCO3 solution and extracted with CH2Cl2. The collected
organic extracts were dried (Na2SO4), filtered, and concentrated
under reduced pressure. The crude product was diluted with
DMF/DMA (13 mL, 1.5 equiv), and the resulting mixture was
stirred at 95 °C for 3 h. After evaporation of volatiles, the
obtained solid was dissolved in CHCl3 (100 mL) and succes-
sively treated with pyridine (5.84 mL, 1.1 equiv) and I2 (33.36 g,
2.0 equiv). The resulting mixture was stirred at room tempera-
ture for 12 h. The reaction was hydrolyzed with saturated aq
Na2S2O3 solution and stirred for 30 min at room temperature.
The aqueous phase was extracted with CH2Cl2. The collected
organic extracts were dried (Na2SO4), filtered, and concentrated
under reduced pressure. Purification by flash chromatography

Article
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21 6845
(20% EtOAc/hexane then 40% EtOAc/hexane) gave 49 (22.53 g,
92% yield) as a colorless solid. 1H NMR (300 MHz, CDCl3):δ8.27
(s, 1H), 8.18 (d, 1H, J=9.6 Hz), 7.16-7.10 (m, 2H), 5.57 (m, 1H),
3.91-3.80 (m, 1H), 3.70-3.62 (m, 1H), 2.10-1.90 (m, 3H),
1.82-1.58 (m, 3H). 13C NMR (400 MHz, CDCl3): δ 172.75,
161.73, 157.72, 157.37, 127.88, 116.51, 116.16, 103.15, 96.54,
86.95, 62.03, 29.93, 24.92, 18.26. MS (ESI) m/z=273.13 [M þ 1].
General Procedure of the Suzuki Coupling for the Synthesis of
50-67. To a solution of 3-iodo-7-(tetrahydropyran-2-yloxy)-
benzopyran-4-one 49 (500 mg, 1.0 equiv) in DME (6 mL) and
H2O (6 mL) were added Na2CO3 (427 mg, 3.0 equiv), arylboro-
nic acid (1.2 equiv), and Pd/C (71 mg, 5 mol %). The resulting
mixture was stirred for 1-4 h at 45 °C and then filtered. The
catalyst was washed with H2O (3 mL) and CH2Cl2 (5 mL). The
aqueous phase was extracted twice with CH2Cl2. The collected
organic extracts were dried (Na2SO4), filtered, and concentrated
under reduced pressure. The crude was purified by flash chro-
matography to give desired products.
20-Methoxy-30,50-difluoro-7-(tetrahydropyran-2-yloxy)isofla-
vone (59). Yield 80%; colorless solid. 1H NMR (300 MHz,
CDCl3): δ 8.24 (d, 1H, J=9.0 Hz), 8.0 (s, 1H), 7.17-7.16 (m,
2H), 6.98-6.89 (m, 2H), 5.60 (m, 1H), 3.92-3.85 (m, 1H), 3.83
(s, 3H), 3.71-3.66 (m, 1H), 2.08-1.92 (m, 3H), 1.80-1.64 (m,
3H). MS (ESI) m/z=388.11 [M þ 1].
30,40,50-Trifluoro-7-(tetrahydropyran-2-yloxy)isoflavone (60).
Yield 83%; colorless solid. 1H NMR (300 MHz, CDCl3):
δ 8.14 (d, 1H, J=9.3 Hz), 7.89 (s, 1H), 7.20-7-03 (m, 2H),
5.58 (m, 1H), 3.91-3.83 (m, 1H), 3.71-3.67 (m, 1H), 2.08-1.94
(m, 3H), 1.78-1.64 (m, 3H). MS (ESI) m/z=377.29 [M þ 1].
3-(2,6-Dimethoxypyridin-3-yl)-7-(tetrahydro-2-yloxy)-benzo-
pyran-4-one (61). Yield 75%; colorless solid. 1H NMR (300
MHz, CDCl3): δ 8.23 (d, 1H, J=8.7 Hz), 8.04 (s, 1H), 7.72 (d,
1H, J=8.1 Hz), 7.14-7.09 (m, 2H), 6.43 (d, 1H, J=8.1 Hz), 5.60
(m, 1H), 3.97 (s, 3H), 3.95 (s, 3H), 3.97-3.84 (m, 1H), 3.70-3.66
(m, 1H), 1.97-1.91 (m, 3H), 1.79-1.63 (m, 3H). MS (ESI) m/z=
384.14 [M þ 1].
40-Chloro-7-(tetrahydropyran-2-yloxy)isoflavone (62). Yield
30,50-Dimethoxy-7-(tetrahydropyran-2-yloxy)isoflavone (50).
Yield 84%; colorless solid. 1H NMR (300 MHz, CDCl3): δ
7.37 (d, 1H, J=9.2 Hz), 7.30 (s, 1H), 6.90 (d, 1H, J=8.3 Hz), 6.75
(t, 1H, J=8.7 Hz), 6.63 (t, 1H, J=7.9 Hz), 3.85 (s, 3H), 3.93 (s,
3H), 5.52 (m, 1H), 3.90-3.81 (m, 1H), 3.72-3.62 (m, 1H), 2.11-
1.90 (m, 3H), 1.82-1.59 (m, 3H). MS (ESI) m/z=383.13 [M þ 1].
40-Methoxy-7-(tetrahydropyran-2-yloxy)isoflavone (51). Yield
1
93%; colorless solid. H NMR (300 MHz, CDCl3): δ 8.15 (d,
1H, J=7.8 Hz), 7.88 (s, 1H), 7.45 (d, 2H, J=9 Hz), 7.34 (d, 2H,
J = 8.4 Hz), 7.05 (m, 2H), 5.50 (m, 1H), 3.79-3.74 (m, 1H),
3.61-3.57 (m, 1H), 1.87-1.83 (m, 3H), 1.68-1.58 (m, 3H). MS
(ESI) m/z=357.07 [M þ 1].
30-Fluoro-7-(tetrahydropyran-2-yloxy)isoflavone (63). Yield
81%; colorless solid. 1H NMR (300 MHz, CDCl3): δ 8.26 (d, 1H,
J=9.6 Hz), 8.01 (s, 1H), 7.44-7.34 (m, 4H), 7.16-7.08 (m, 2H),
5.60 (m, 1H), 3.89-3.85 (m, 1H), 3.71-3.68 (m, 1H), 1.97-1.92
(m, 3H), 1.80-1.64 (m, 3H). MS (ESI) m/z=341.13 [M þ 1].
20-Methoxy-7-(tetrahydropyran-2-yloxy)isoflavone (64).
Yield 78%; colorless solid. 1H NMR (300 MHz, CDCl3): δ
8.25 (d, 1H, J = 8.7 Hz), 7.95 (s, 1H), 7.42-7.33 (m, 3H),
7.15-7.07 (m, 3H), 5.59 (m, 1H), 3.93-3.80 (m, 1H), 3.82 (s,
3H), 3.74-3.65 (m, 1H), 1.97-1.92 (m, 3H), 1.78-1.64 (m, 3H).
MS (ESI) m/z=353.15 [M þ 1].
1
81%; colorless solid. H NMR (300 MHz, CDCl3): δ 8.20 (d,
1H, J = 9.2 Hz), 7.91 (s, 1H), 7.49 (dd, 2H, J = 2.2 Hz,
6.8 Hz), 7.08 (d, 2H, J=6.7 Hz), 6.96 (d, 2H, J=8.8 Hz), 5.55
(m, 1H), 3.83 (s, 1H), 3.91-3.82 (m,1H), 3.71-3.62 (m, 1H),
2.06-1.89 (m, 3H), 1.80-1.59 (m, 3H). MS (ESI) m/z= 353.15
[M þ 1].
30,40-Methylenedioxy-7-(tetrahydropyran-2-yloxy)isoflavone
(52). Yield 95%; colorless solid. 1H NMR (300 MHz, CDCl3): δ
8.24 (d, 1H, J=9.3 Hz), 7.95 (s, 1H), 7.15-7.11 (m, 3H), 7.0 (dd,
1H, J=1.5 Hz, 8.1 Hz), 6.90 (d, 1H, J=8.1 Hz), 6.03 (s, 2H),
5.59 (m, 1H), 3.94-3.84 (m, 1H), 3.73-3.65 (m, 1H), 2.10-1.89
(m, 3H), 1.80-1.60 (m, 3H). MS (ESI) m/z=367.20 [M þ 1].
40-Trifluoromethyl-7-(tetrahydropyran-2-yloxy)isoflavone (53).
Yield 74%; colorless solid. 1H NMR (300 MHz, CDCl3): δ
8.27-8.23 (m, 2H), 8.03 (s, 1H), 7.73 (s, 1H), 7.18-7.14 (m, 4H),
5.61 (m, 1H), 3.94-3.85 (m, 1H), 3.74-3.65 (m, 1H), 2.09-1.90
(m, 3H), 1.83-1.60 (m, 3H). MS (ESI) m/z=391.23 [M þ 1].
40-Fluoro-7-(tetrahydropyran-2-yloxy)isoflavone (54). Yield
30-Trifluoromethoxy-7-(tetrahydropyran-2-yloxy)isoflavone (65).
Yield 79%; colorless solid. 1H NMR (300 MHz, CDCl3): δ
8.26 (d, 1H, J=8.1 Hz), 8.02 (s, 1H), 7.55-7.45 (m, 3H), 7.28 (d,
1H J=8.1 Hz), 7.16 (d, 1H, J=8.7 Hz), 7.14 (s, 1H), 5.60 (m,
1H), 3.89-3.85 (m, 1H), 3.72-3.65 (m, 1H), 1.98-1.93 (m, 3H),
1.79-1.66 (m, 3H). MS (ESI) m/z=407.10 [M þ 1].
30-Benzyloxy-7-(tetrahydropyran-2-yloxy)isoflavone (66).
Yield 88%; colorless solid. 1H NMR (300 MHz, CDCl3): δ 8.27
(d, 1H, J=9.3 Hz), 7.99 (s, 1H), 7.49-7.35 (m, 7H), 7.18-7.13
(m, 1H), 7.05-7.01 (m, 1H), 6.96 (d, 1H, J=9 Hz), 6.89 (s, 1H),
5.60 (m, 1H), 5.13 (s, 2H), 3.88-3.83 (m, 1H), 3.74-3.65 (m,
1H), 1.97-1.94 (m, 3H), 1.81-1.63 (m, 3H). MS (ESI) m/z=
429.20 [M þ 1].
1
85%; colorless solid. H NMR (300 MHz, CDCl3): δ 8.42 (d,
1H, J=8.7 Hz), 8.01 (s, 1H), 7.65 (m, 2H), 7.28 (t, 2H, J=8.7
Hz), 6.99 (dd, 1H, J=2.1 Hz, 8.4 Hz), 6.90 (d, 1H, J=2.4 Hz),
5.57 (m, 1H), 3.94-3.70 (m, 1H), 3.71-3.60 (m, 1H), 2.11-1.90
(m, 3H), 1.81-1.63 (m, 3H). MS (ESI) m/z=341.14 [M þ 1].
30,40-Dimethoxy-7-(tetrahydropyran-2-yloxy)isoflavone (55).
Yield 92%; colorless solid. 1H NMR (300 MHz, CDCl3): δ
8.22 (d, 1H, J=9.5 Hz), 7.94 (s, 1H), 7.22 (m, 1H), 7.11- 7.03 (m,
3H), 6.92 (d, 2H, J=8.4 Hz), 5.57 (m, 1H), 3.95 (s, 3H), 3.93
(s, 3H), 3.94-3.70 (m, 1H), 3.71-3.60 (m, 1H), 2.11-1.90
(m, 3H), 1.81-1.63 (m, 3H). MS (ESI) m/z=383.40 [M þ 1].
3-(2,3-Dihydro-1,4-benzodioxin-6-yl)-7-(tetrahydropyran-
30,40,50-Trimethoxy-7-(tetrahydropyran-2-yloxy)isoflavone (67).
Yield 76%; colorless solid. 1H NMR (300 MHz, CDCl3):
δ 8.26 (d, 1H, J=7.8 Hz), 8.00 (s, 1H), 7.16 (s, 2H), 7.13 (d,
1H J=8.7 Hz), 6.82 (s, 1H), 5.60 (m, 1H), 3.93 (s, 6H), 3.91 (s,
3H), 3.93-3.85 (m, 1H), 3.72-3.65 (m, 1H), 1.97-1.93 (m, 3H),
1.79-1.69 (m, 3H). MS (ESI) m/z=413.15 [M þ 1].
30,50-Dimethoxy-7-hydroxyisoflavone (68). To a solution of
30,50-dimethoxy-7-(tetrahydropyran-2-yloxy)isoflavone 50 (400
mg, 1.0 equiv) in MeOH (30 mL) and THF (30 mL) was added
1
2-yloxy)isoflavone (56). Yield 90%; colorless solid. H NMR
(300 MHz, CDCl3): δ 8.26 (d, 1H, J = 8.1 Hz), 7.94 (s, 1H),
7.14-6.93 (m, 5H), 5.59 (m, 1H), 4.33 (s, 4H), 3.92-3.84 (m,
1H), 3.70-3.65 (m, 1H), 1.97-1.92 (m, 3H), 1.75-1.66 (m, 3H).
MS (ESI) m/z=381.18 [M þ 1].
p-TsOH H2O (20 mg, 0.1 equiv) at room temperature. The
3
resulting mixture was stirred at 60 °C for 1 h and then Et3N
(0.14 mL, 1.0 equiv) was added and volatiles were removed
under reduced pressure. Purification by flash chromatography
(40% EtOAc/hexane then 5% MeOH/EtOAc) provided 68
2-,40-Difluoro-7-(tetrahydropyran-2-yloxy)isoflavone (57).
Yield 82%; colorless solid. 1H NMR (300 MHz, CDCl3): δ 8.39
(d, 1H, J=9.1 Hz), 8.18 (s, 1H, J=9 Hz), 6.90-7.98 (m, 5H),
5.57 (m, 1H), 3.94-3.70 (m, 1H), 3.71-3.60 (m, 1H), 2.11-1.90
(m, 3H), 1.81-1.63 (m, 3H). MS (ESI) m/z=359.23 [M þ 1].
30-Methoxy-7-(tetrahydropyran-2-yloxy)isoflavone (58).
Yield 77%; colorless solid. 1H NMR (300 MHz, CDCl3): δ 8.25
(d, 1H, J=9.3 Hz), 7.98 (s, 1H), 7.40-6.92 (m, 6H), 5.58 (m, 1H),
3.86 (s, 3H), 3.93-3.80 (m, 1H), 3.74-3.60 (m, 1H), 2.08-1.85
(m, 3H), 1.80-1.59 (m, 3H). MS (ESI) m/z=353.15 [M þ 1].
1
(265 mg, 85% yield) as a colorless solid. H NMR (300 MHz,
DMSO): δ 8.43 (s, 1H), 7.99 (d, 1H, J=9.1 Hz), 6.98 (d, 1H),
6.95 (d, 1H, J=8.2 Hz), 6.90 (d, 1H, J=7.8 Hz), 6.78 (d, 1H,
J=8.8 Hz), 6.55 (t, 1H, J=7.6 Hz), 3.79 (s, 6H). 13C NMR
(400 MHz, DMSO): δ 174.70, 163.14, 160.57, 157.78, 154.53,
134.40, 127.79, 123.74, 117.05, 115.74, 107.51, 102.60, 100.09,
55.67. MS (ESI) m/z=299.15 [M þ 1]. HRMS (ESI) calcd for
(C17H14O5 þ H) 299. 0919, found 299.0914.

6846 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21
Matin et al.
Compounds 69-85 were made using the same procedure as
for the preparation of compound 70 using appropriate starting
materials.
20-Methoxy-30,50-difluoro-7-hydroxyisoflavone (77). Yield
86%; colorless solid. H NMR (300 MHz, DMSO): δ 10.84
1
(br s, 1H), 8.33 (s, 1H), 7.98 (d, 1H, J=8.7 Hz), 7.41 (t, 1H, J=
8.7 Hz), 7.10 (d, 1H, J=9 Hz), 6.99 (d, 1H, J=8.7 Hz), 6.92 (s,
1H), 3.73 (s, 3H). 13C NMR (400 MHz, DMSO): δ 174.24,
163.33, 158.38 (d, J=50.4 Hz), 158.03, 156.66 (d, J=53.2 Hz),
155.97 (d, J=50.8 Hz), 155.06, 154.20 (d, J=53.6 Hz), 142.97
(q, J = 44.4 Hz), 128.89 (q, J = 41.6 Hz), 127.66, 120.50,
116.75, 115.88, 114.33 (dd, J=13.6 Hz, 92.4 Hz), 105.60 (q, J=
94 Hz), 102.76, 61.67. MS (ESI) m/z=305.10 [M þ 1]. HRMS
(ESI) calcd for (C16H10O4F2 þ H) 305. 0619, found 305.0619.
30,40,50-Trifluoro-7-hydroxyisoflavone (78). Yield 78%; color-
less solid. 1H NMR (300 MHz, DMSO): δ 10.83 (br s, 1H), 8.55
(s, 1H), 8.0 (d, 1H, J=8.7 Hz), 7.63 (t, 1H, J=9.6), 6.97 (d, 1H,
J=9 Hz), 6.91 (s, 2H). 13C NMR (400 MHz, DMSO): δ 174.24,
163.41, 157.80, 155.52, 151.59 (q, J=16.4 Hz), 149.14 (q, J=16.4
Hz), 139.92 (t, J=60.8 Hz), 137.43 (t, J=182.4 Hz), 129.42 (q,
J=18 Hz), 127.78, 102.80, 116.78, 116.02, 113.87 (q, J=22.4
Hz), 102.70. MS (ESI) m/z=293.06 [M þ 1]. HRMS (ESI) calcd
for (C15H7O3F3 þ H) 293. 0347, found 269.0350.
40-Methoxy-7-hydroxyisoflavone or Formononetin (69). Yield
83%; colorless solid. 1H NMR (300 MHz, DMSO): δ 10.84 (br s,
1H), 8.34 (s, 1H), 8.0 (d, 1H, J=8.7 Hz), 7.53 (dd, 1H, J=2.5 Hz,
8.3 Hz), 7.01-6.87 (m, 5H), 3.79 (s, 3H). 13C NMR (400 MHz,
DMSO): δ 175.05, 163.00, 159.40, 157.89, 153.59, 130.51,
127.74, 124.67, 123.60, 117.06, 115.63, 114.04, 102.57, 55.59.
MS (ESI) m/z = 269.12 [M þ 1]. HRMS (ESI) calcd for
(C16H12O4 þ H) 269.0813, found 269.0809.
30,40-Methylenedioxy-7-hydroxyisoflavone or ψ-baptigenin (70).
Yield 80%; colorless solid. 1H NMR (300 MHz, DMSO): δ 10.82
(br s, 1H), 8.36 (s, 1H), 7.99 (d, 1H, J=9 Hz), 7.17-6.88 (m, 5H),
6.06 (s, 2H). 13C NMR (400 MHz, DMSO): δ 174.91, 163.06,
157.84, 153.89, 147.43, 147.33, 127.76, 126.19, 123.60, 122.83,
117.00, 115.68, 109.87, 108.53, 102.57, 101.47. MS (ESI) m/z =
283.09 [M þ 1]. HRMS (ESI) calcd for (C16H10O5 þ H) 283. 0601,
found 283.0600.
40-Trifluoromethyl-7-hydroxyisoflavone (71). Yield 87%; col-
orless solid. 1H NMR (300 MHz, DMSO): δ 10.85 (s, 1H), 8.54
(s, 1H), 8.02 (d, 1H, J=8.7 Hz), 7.82 (dd, 2H, J=1.8 Hz, 9.3 Hz),
7.01-6.92 (m, 4H). 13C NMR (400 MHz, DMSO): δ 174.50,
163.33, 157.92, 155.26, 136.94, 130.07, 128.70, 128.39, 127.79,
126.11, 125.43 (q, J=14.8 Hz), 125.39, 123.40, 122.70, 115.92,
102.72. MS (ESI) m/z=307.08 [M þ 1]. HRMS (ESI) calcd for
(C16H9O3F3 þ H) 307. 0576, found 307.0575.
3-(2,6-Dimethoxypyridin-3-yl)-7-hydroxy-benzopyran-4-one (79).
Yield 83%; colorless solid. 1H NMR (300 MHz, DMSO): δ
10.85 (br s, 1H), 8.26 (s, 1H), 7.95 (d, 1H, J=8.7 Hz), 7.63 (d, 1H,
J=8.1 Hz), 6.97 (d, 1H, J=9 Hz), 6.89 (s, 1H), 6.47 (d, 1H, J=
8.1 Hz), 3.91 (s, 3H), 3.84 (s, 3H). 13C NMR (400 MHz, DMSO):
δ 174.65, 163.06, 162.69, 160.36, 157.95, 155.02, 143.78, 127.62,
120.24, 116.84, 115.66, 106.68, 102.65, 100.91, 53.78, 53.69. MS
(ESI) m/z=300.10 [M þ 1]. HRMS (ESI) calcd for (C16H13NO5
þ H) 300. 0793, found 300.0790.
40-Fluoro-7-hydroxyisoflavone (72). Yield 85%; colorless
1
solid. H NMR (300 MHz, DMSO): δ 10.84 (br s, 1H), 8.42
(s, 1H), 8.01 (d, 1H, J=8.7 Hz), 7.65 (m, 2H), 7.28 (t, 2H, J=
8.7 Hz), 6.99 (dd, 1H, J=2.1 Hz, 8.4 Hz), 6.90 (d, 1H, J=2.4 Hz).
13C NMR (400 MHz, DMSO): δ 174.79, 163.48, 163.17, 161.05,
157.93, 154.30, 133.44 (d, J=832.8 Hz), 128.89, 127.76, 123.01,
166.99, 115.53 (t, J=95.2 Hz), 102.63. MS (ESI) m/z=257.10
[M þ 1]. HRMS (ESI) calcd for (C15H9O3F þ H) 257. 0603,
found 269.0608.
30,40-Dimethoxy-7-hydroxyisoflavone (73). Yield 83%; color-
less solid. 1H NMR (300 MHz, DMSO): δ 10.86 (br s, 1H), 8.38
(s, 1H), 7.98 (d, 1H, J=8.87 Hz), 7.24-7.03 (m, 6.92 (d, 2H,
J=8.4 Hz), 5.57 (m, 1H), 3.95 (s, 3H), 3.93 (s, 3H). 13C NMR
(400 MHz, DMSO): δ 175.02, 163.09, 157.84, 153.78, 149.04,
148.72, 127.74, 125.00, 123.68, 121.67, 117.04, 115.67, 113.26,
112.00, 102.55, 56.00, 55.98. MS (ESI) m/z=299.15 [M þ 1].
HRMS (ESI) calcd for (C17H14O5 þ H) 299. 0841, found
269.0839.
40-Chloro-7-hydroxyisoflavone (80). Yield 85%; colorless so-
1
lid. H NMR (300 MHz, DMSO): δ 10.85 (br s, 1H), 8.46 (s,
1H), 8.01 (d, 1H, J=8.7 Hz), 6.64 (d, 2H, J=8.7 Hz), 6.52 (d, 2H,
J=8.4 Hz), 6.99-6.90 (m, 2H). 13C NMR (400 MHz, DMSO): δ
174.65, 163.22, 157.91, 154.58, 132.92, 131.45, 131.10, 128.57,
127.77, 122.77, 116.96, 115.82, 102.66. MS (ESI) m/z=273.40
[M þ 1]. HRMS (ESI) calcd for (C15H9O3Cl þ H) 273. 0313,
found 273.0315.
30-Fluoro-7-hydroxyisoflavone (81). Yield 80%; colorless so-
1
lid. H NMR (300 MHz, DMSO): δ 10.86 (br s, 1H), 8.49 (s,
1H), 8.01 (d, 1H, J=8.7 Hz), 7.50-7.45 (m, 2H), 7.21-7.23 (m,
2H), 6.99-6.90 (m, 2H). 13C NMR (400 MHz, DMSO): δ
174.59, 163.51, 163.26, 161.09, 157.85, 154.91, 134.95 (d, J =
43.4 Hz), 130.50 (d, J=34 Hz), 127.79, 125.30, 122.65, 116.95,
116.19 (d, J=88.4 Hz), 115.86, 115.02 (d, J=83.6 Hz), 102.65.
MS (ESI) m/z = 257.10 [M þ 1]. HRMS (ESI) calcd for
(C16H9O3F þ H) 257. 0535, found 257.0601.
3-(2,3-Dihydro-1,4-benzodioxin-6-yl)-7-hydroxyisoflavone (74).
Yield 88%; colorless solid. 1H NMR (300 MHz, DMSO): δ
10.84 (br s, 1H), 8.35 (s, 1H), 7.99 (d, 1H, J=8.7 Hz), 7.13-6.87
(m, 5H), 4.26 (s, 4H). 13C NMR (400 MHz, DMSO): δ 174.91,
163.01, 157.81, 153.80, 143.61, 143.36, 127.76, 125.47, 123.29,
122.22, 118.06, 117.12, 117.04, 115.63, 102.55, 64.61, 64.49.
MS (ESI) m/z = 297.10 [M þ 1]. HRMS (ESI) calcd for
(C17H12O5 þ H) 297. 0751, found 297.0757.
20-Methoxy-7-hydroxyisoflavone (82). Yield 84%; colorless
solid. 1H NMR (300 MHz, DMSO): δ 10.81 (br s, 1H), 8.19 (s,
1H), 7.95 (d, 1H, J=8.7 Hz), 7.39 (t, 1H, J=8.4 Hz), 7.25 (d,
1H, J =7.5 Hz), 7.10-6.88 (m, 4H), 3.72 (s, 3H). 13C NMR
(400 MHz, DMSO): δ 174.62, 162.96, 157.99, 157.89, 154.40,
132.00, 130.03, 127.64, 122.38, 121.62, 120.51, 116.98, 115.57,
11.69, 102.63, 55.93. MS (ESI) m/z=269.33 [M þ 1]. HRMS
(ESI) calcd for (C16H12O4 þ H) 269. 0808, found 269.0809.
30-Trifluoromethoxy-7-hydroxyisoflavone (83). Yield 81%;
colorless solid. 1H NMR (300 MHz, DMSO): δ 10.85 (br s,
1H), 8.53 (s, 1H), 8.02 (d, 1H, J=8.7 Hz), 7.65-7.58 (m, 3H),
20,40-Difluoro-7-hydroxyisoflavone (75). Yield 85%; colorless
solid. 1H NMR (300 MHz, DMSO): δ 10.83 (br s, 1H), 8.39 (s,
1H), 8.18 (d, 1H, J=9 Hz), 6.90-7.98 (m, 5H). 13C NMR (400
MHz, DMSO): δ 174.02, 164.02 (d, J=49.2 Hz), 163.32, 161.97
(d, J=48 Hz), 159.49 (d, J=50.8 Hz), 158.05, 155.34, 133.79 (q,
J = 19.6 Hz), 127.63, 119.22, 116.97 (d, J = 64 Hz), 116.64,
115.92, 111.86 (dd, J=13.2 Hz, 84.8 Hz), 102.77. MS (ESI) m/z=
275.08 [M þ 1]. HRMS (ESI) calcd for (C15H8O3F2 þ H) 275.
0514, found 275.0515.
7.40 (d, 1H, J=8.4 Hz), 6.99 (d, 1H, J=8.7 Hz), 6.92 (s, 1H). 13
C
NMR (400 MHz, DMSO): δ 174.57, 163.35, 157.89, 155.11, 148
(d, J=7.6 Hz), 134.87, 130.51, 128. 21, 127.78, 122.29, 121.85,
120.61, 119.30, 116.90, 115.93, 102.68. MS (ESI) m/z=323.27
[M þ 1]. HRMS (ESI) calcd for (C16H9O4F3 þ H) 323.0525,
found 323.0527.
30-Benzyloxy-7-hydroxyisoflavone (84). Yield 85%; colorless
solid. 1H NMR (300 MHz, DMSO): δ 10.85 (br s, 1H), 8.42 (s,
1H), 8.01 (d, 1H, J=9 Hz), 7.50-7.33 (m, 7H), 7.18 (d, 1H, J=
7.5 Hz), 7.05 (d, 1H, J=8.7 Hz), 6.98 (d, 1H, J=9 Hz), 6.90 (s,
1H), 5.14 (s, 2H). 13C NMR (400 MHz, DMSO): δ 174.81,
163.11, 158.56, 157.85, 154.46, 137.49, 133.89, 129.63, 128.89,
128.29, 128.15, 127.79, 123.69, 121.89, 117.05, 115.96, 115.76,
30-Methoxy-7-hydroxyisoflavone (76). Yield 80%; colorless
solid. 1H NMR (300 MHz, DMSO): δ 10.86 (br s, 1H), 8.41 (s,
1H), 8.01 (d, 1H, J=8.7 Hz), 7.34-6.90 (m, 5H), 6.90 (dd, 1H,
J=2.4 Hz, 8.3 Hz), 3.80 (s, 1H). 13C NMR (400 MHz, DMSO): δ
174.77, 163.13, 159.43, 157.84, 154.39, 133.88, 129.56, 127.77,
123.77, 121.61, 117.07, 115.72, 115.06, 113.67, 102.61, 55.51. MS
(ESI) m/z=269.10 [M þ 1]. HRMS (ESI) calcd for (C16H12O4 þ
H) 269. 0813, found 269.0808.

Article
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21 6847
114.44, 102.61, 69.68. MS (ESI) m/z=345.27 [M þ 1]. HRMS
(ESI) calcd for (C22H16O4 þ H) 345.1121, found 345.1118.
30,40,50-Trimethoxy-7-hydroxyisoflavone (85). Yield 77%; col-
(4 mL) was slowly added. The resulting mixture was then heated
to 100 °C. After the completion of the reaction, the reaction
mixture was poured into water (100 mL) and left overnight to
give a precipitate, which was then stirred for 2 h in cold methanol
(3 mL), filtered, and crystallized in a alcoholic solvents.
40,6,7,-Trihydroxyisoflavone (93). Crystallized in a mixture of
water/ethanol. Yield 57%; colorless solid. 1H NMR (300 MHz,
DMSO): δ 9.95 (brs, 1H), 8.37 (s, 1H), 7.48 (s, 1H), 7.43 (d, 2H,
J=8.7 Hz), 6.93 (s, 1H), 6.81 (d, 2H, J=8.7 Hz), 4.53 (dd, 1H, J=
11.0 Hz, 13.2 Hz), 4.49 (dd, 1H, J=5.7 Hz, 5.9 Hz), 4.05 (dd, 1H,
J=5.5 Hz, 7.2 Hz).; 13C NMR (400 MHz, DMSO): δ 174.82,
157.47, 152.82 (d, J=62.4 Hz), 151.27, 145.06, 130.50, 123.35 (d,
J=84.8 Hz), 117.02, 115.33, 108.52, 103.17. MS (ESI) m/z=
271.10 [M þ 1]. HRMS (ESI) calcd for (C16H10O5 þ H)
271.0528, found 271.0523.
1
orless solid. H NMR (300 MHz, DMSO): δ 10.86 (br s, 1H),
8.44 (s, 1H), 8.01 (d, 1H, J=8.7 Hz), 6.98 (d, 1H, J=8.7 Hz), 6.90
(s, 2H), 6.89 (s, 1H), 3.81 (s, 6H), 3.70 (s, 3H). 13C NMR (400
MHz, DMSO): δ 174.84, 163.10, 157.80, 154.34, 152.99, 137.71,
128.03, 127.77, 123.79, 117.04, 115.73, 106.93, 102.58, 60.48,
56.38. MS (ESI) m/z=329.33 [M þ 1].; HRMS (ESI) calcd for
(C18H16O6 þ H) 329.1019, found 329.1018.
30,50,7-Trihydroxyisoflavone (86). To a portion (500 mg) of
30,50-dimethoxy-7-hydroxyisoflavone 68 dissolved in anhyd di-
chloromethane (15 mL) and cooled to 0 °C, a 1 M solution of
BBr3 in dichloromethane (6 mL) was dropped slowly; the
solution was stirred at room temperature for 6 h and then was
diluted with iced water. The pH was arranged to 6 with 5%
Na2HPO4, the mixture was extracted with ethyl acetate, and the
organic layer was separated and washed with brine, dried, and
concentrated to yield, after crystallization from dichloro-
methane/methanol/ethyl acetate, 86 as light-orange color solid
(258 mg, 57% yield).
40,5,7-Trihydroxyisoflavone or Genistein (94). Crystallized in
ethanol. 71%; colorless solid. 1H NMR (300 MHz, DMSO): δ
9.95 (brs, 1H), 8.37 (s, 1H), 7.48 (s, 1H), 7.43 (d, 2H, J=8.7 Hz),
6.93 (s, 1H), 6.81 (d, 2H, J=8.7 Hz), 4.53 (dd, 1H, J=11.0 Hz,
13.2 Hz), 4.49 (dd, 1H, J=5.7 Hz, 5.9 Hz), 4.05 (dd, 1H, J=5.5
Hz, 7.2 Hz). MS (ESI) m/z=271.30 [M þ 1].
1H NMR (300 MHz, DMSO): δ 8.30 (s, 1H), 7.99 (d, 1H, J=
8.3 Hz), 6.92 (dd, 1H, J=2.2 Hz, 8 Hz), 6.83 (d, 1H, J=2.5 Hz),
30,40-Methylenedioxy-7-methoxyisoflavone or 7-Methoxy-
ψ-baptigenin (95). To a solution of (150 mg) of ψ-baptigenin
70 in dry DMF (5 mL) were added K2CO3 (110 mg, 1.5 mmol)
and MeI (0.05 mL, 1.5 mmol). The solution was stirred at room
temperature for 3 h and then was extracted with ethyl acetate,
and the organic layer was separated and washed with brine,
dried, and concentrated to get crude product. The crude was
purified by flash chromatography (50% EtOAc/hexane) to give
95 (140 mg, 90% yield) as a colorless solid. 1H NMR (300 MHz,
DMSO): δ 8.46 (s, 1H), 8.06 (d, 1H, J=9 Hz), 7.20-6.98 (m,
5H), 6.07 (s, 2H), 3.93 (s, 3H). 13C NMR (400 MHz, DMSO): δ
174.95, 164.20, 157.85, 154.21, 147.45, 147.39, 127.41, 126.01,
123.82, 122.86, 117.98, 115.27, 109.84, 108.55, 101.50, 101.02,
56.58. MS (ESI) m/z=297.11 [M þ 1]. HRMS (ESI) calcd for
(C17H12O5 þ H) 297.0757, found 297.0752.
6.72 (d, 1H, J=2.2 Hz), 6.42 (d, 1H, J=2.4 Hz), 6.23 (s, 1H). 13
C
NMR (400 MHz, DMSO): δ 174.77, 163.08, 158.48, 157.76,
153.90, 134.04, 127.77, 126.02, 124.31, 117.11, 116.97, 115.62,
102.56. MS (ESI) m/z=271.08 [M þ 1]. HRMS (ESI) calcd for
(C15H10O9 þ H) 271.0601, found 271.0607.
Compounds 87 and 88 were made using the same procedure
as for the preparation of compound 86 using appropriate
starting materials.
40,7-Dihydroxyisoflavone or Daidzein (87). Yield 65%; light-
orange color solid. 1H NMR (300 MHz, DMSO): δ 10.74 (brs,
1H), 9.50 (brs, 1H), 8.26 (s, 1H), 7.95 (d, 1H, J=8.7 Hz), 7.37 (dt,
2H, J=2, 8.6 Hz), 6.93 (dd, 1H, J=2.2, 8.7 Hz), 6.85 (d, 1H, J=2
Hz), 6.80 (dt, 2H, J = 2.2, 8.6 Hz). 13C NMR (400 MHz,
DMSO): δ 174.83, 162.78, 157.64, 157.32, 152.97, 130.21,
127.43, 123.67, 122.75, 116.84, 115.24, 115.17, 102.28. MS
(ESI) m/z=255.10 [M þ 1].
2-(30,40-Methylenedioxy)-1-(5-ethyl-2,4-dihydroxyphenyl)eth-
anone (97). This compound was made using the same procedure
as for the preparation of compound 91 using appropriate
starting materials. Crystallized in isopropyl alcohol; yield
30,4’,7-Trihydroxyisoflavone (88). Yield 52%; light-orange
1
1
color solid. H NMR (300 MHz, DMSO): δ 8.37 (s, 1H), 7.98
51%; colorless solid. H NMR (300 MHz, CDCl3): δ 7.34 (s,
(d, 1H, J=8.5 Hz), 7.63 (dd, 1H, J=2.4 Hz, 7.9 Hz), 7.60 (d, 1H,
J=2.3 Hz), 7.52 (d, 1H, J=8.1 Hz), 6.90 (dd, 1H, J=2.5 Hz, 8.2
Hz), 6.83 (d, 1H, J=2.3 Hz). 13C NMR (400 MHz, DMSO): δ
174.86, 163.03, 158.53, 157.77, 152.95, 134.06, 127.68, 125.98,
124.28, 117.14, 116.97, 115.67, 102.54. MS (ESI) m/z=271.10
[M þ 1]. HRMS (ESI) calcd for (C16H10O5 þ H) 271. 0528,
found 271.0520.
1H), 6.90-6.85 (m, 3H), 6.28 (s, 1H), 5.98 (s, 2H), 4.22 (s, 2H),
2.53 (q, 2H), 1.18 (t, 3H). MS (ESI) m/z=301.11 [M þ 1].
30,40-Methylenedioxy)-6-ethyl-7-hydroxyisoflavone (98). With
stirring, boron trifluoride etherate (1.30 mL, 6 mmol) was added
dropwise to a solution of 97 (600 mg, 1 mmol) in DMF (2.7 mL).
Then phosphorus pentachloride (384 mg, 1.1 mmol) was added
at such a rate that the temperature of the reaction mixture did
not rise above 60-70 °C. After the completion of the reaction,
the reaction mixture was poured into water (100 mL), and the
resulting mixture was kept at 70 °C for 1 h. The precipitate was
filtered and crude product crystallized from isopropyl alcohol to
General Procedure for the Synthesis of Compound 91-94.
With stirring, a rapid current of dry hydrogen chloride
was passed for 10 min into a solution of 4-hydroxyphenyl
acetonitrile (500 mg, 1 mmol) in dry toluene (10 mL), cooled
to 0 °C, and anhyd zinc chloride (255 mg, 0.5 mmol) in dry ether
(5 mL) was added. The corresponding polyhydroxybenzene
(1.1 mmol) was added portionwise with constant bubbling of
gaseous HCl for a further 4-6 h, and then the reaction mixture
was stirred overnight at room temperature. The solvent was
decanted and triturated twice with dry toluene. The hot water
(50 mL) was added and the mixture was kept at 90 °C and pH 1
for 30 min. The product was separated from the hot solution and
washed several times with water. The ketiminium chloride
intermediate that separated as an oil after 3-4 days was washed
with diethyl ether and hydrolyzed by refluxing in 5% HCl
(10 mL) for 4-5 h. The corresponding ketone (91 or 92), which
separated upon cooling, was filtered and dried under reduced
pressure.
1
give 98 as a white solid (452 mg, 73%). H NMR (300 MHz,
DMSO): δ 10.87 (br s, 1H), 8.33 (s, 1H), 7.81 (s, 1H), 7.13 (d, 1H,
J=1.5 Hz), 7.04 (dd, 1H, J=1.5 Hz, 8.1 Hz), 6.96 (d, 1H, J=8.1
Hz), 6.88 (s, 1H), 6.04 (s, 2H), 2.64 (q, 2H), 1.17 (t, 3H). 13C
NMR (400 MHz, DMSO): δ 174.85, 161.14, 156.13, 153.65,
147.41, 147.28, 130.63, 126.38, 125.37, 123.52, 122.78, 116.67,
109.88, 108.53, 101.85, 101.46, 22.84, 14.24. MS (ESI) m/z =
311.15 [M þ 1]. HRMS (ESI) calcd for (C18H14O5 þ H)
311.0841, found 311.0847.
30,40-Methylenedioxy-6-ethyl-2-(trifluoromethyl)-7-hydroxyi-
soflavone (99). A solution of trifluoroacetic anhydride (0.37 mL)
was added to a solution of 97 (400 mg) in 2 mL of dry pyridine at
0 °C. The reaction mixture was shaken, with ice cooling, for
10-15 min, and was left overnight. On the following day, it was
heated to 40-50 °C for 10-15 min and again left at room
temperature for 12 h. Then it was poured into 20-30 mL cold
water, and the precipitate was filtered off and crystallized from
ethanol to give 99 as an off-white solid (388 mg, 77%). 1H NMR
With stirring, boron trifluoride etherate (6 mmol) was added
dropwise to a solution of corresponding ketone (91 or 92)
(1 mmol) in DMF (8 mL). This solution was warmed to 50 °C,
and a solution of methanesulfonyl chloride (0.5 mmol) in DMF

6848 Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21
Matin et al.
(300 MHz, DMSO): δ 11.22 (s, 1H), 7.76 (s, 1H), 6.97 (d, 1H, J=
8.1 Hz), 6.92 (s, 1H), 6.84 (d, 1H, J=1.5 Hz), 6.71 (dd, 1H, J=
1.8, 8.1 Hz), 6.08 (s, 2H), 2.65 (q, 2H), 1.16 (t, 3H). 13C NMR
(400 MHz, DMSO): δ 175.45, 162.34, 155.14, 147.84, 147.27,
146.97 (d, J=140 Hz), 131.99, 125.46, 125.01, 123.96, 123.38,
121.22, 118.47, 115.54, 110.84, 108.35, 101.82, 22.81, 14.21. MS
(ESI) m/z=379.21 [M þ 1]. HRMS (ESI) calcd for (C19H13O5F3
þ H) 379.0715, found 379.0720.
to give a pale-yellow precipitate. The solids were removed by
filtration and washed with water (50 mL). The crude produced
was extracted with ethyl acetate, and the organic layer was
separated and washed with brine, dried, and concentrated
to yield, after trituration with diethyl ether (50 mL) gave 106
(626 mg, 28%) as a pale-orange solid after drying in vacuo.
1H NMR (300 MHz, CDCl3): δ 12.11 (br s, 1H), 7.55 (d, 1H,
J=8.9 Hz), 7.05-6.95 (m, 4H), 6.20-6.10 (m, 2H), 3.95 (s, 2H).
MS (ESI) m/z=247.15 [M þ 1].
30,40-Methylenedioxy-6-ethyl-7-acetoxyisoflavone (100).
A
mixture of 97 (500 mg, 1 mmol), acetic anhydride (0.67 mL
5 mmol), and triethylamine (0.81 mL, 4 mmol) was heated at
120-130 °C for 6 h. Then the reaction mixture was added to cold
water containing 0.2 mL of hydrochloric acid. The precipitate
that deposited was filtered off, washed with water until free from
smell, dried, and crystallized from ethyl acetate to give 100 as an
off-white solid (433 mg, 71%). 1H NMR (300 MHz, CDCl3): δ
8.88 (s, 1H), 7.94 (s, 1H), 7.23 (s, 1H), 7.09 (d, 1H, J=2 Hz), 6.98
(dd, 2H, J=7.8 Hz), 6.85 (d, 1H, J=8.1 Hz), 5.99 (s, 2H), 2.66 (q,
2H), 2.38 (s, 3H), 2.26 (s, 3H), 1.26 (t, 3H). MS (ESI) m/z =
367.16 [M þ 1].
1-(2,4-Dihydroxyphenyl)-2-(4-methoxyphenyl)ethenone (107).
This compound was made using the same procedure as for the
preparation of compound 106 using appropriate starting mate-
rials. Yield 20%; orange solid. 1H NMR (DMSO, 300 MHz): δ
7.95 (d, 1H, J = 8.9 Hz), 7.22 (d, 2H, J = 8.7 Hz), 6.9 (d, 2H,
J = 8.7 Hz), 6.42 (d, 1H, J = 9.8 Hz), 6.25 (s, 1H), 4.18 (s, 2H),
3.75 (s, 3H). MS (ESI) m/z=259.10 [M þ 1].
40-Fluoro-2-trifluoromethyl-7-hydroxyisoflavone (108). This
compound was made using the same procedure as for the
preparation of compound 99 using appropriate starting materi-
als. Yield 73%; off-white solid. 1H NMR (300 MHz, DMSO): δ
11.18 (s, 1H), 7.93 (d, 1H, J=8.7 Hz), 7.36-7.25 (m, 4H), 7.03
(dd, 1H, J=2.4, 9 Hz), 6.95 (d, 1H, J=2.4 Hz). 13C NMR (400
MHz, DMSO): δ 175.47, 164.31, 163.88, 161.44, 147.20, 132.58
(d, J=32.8 Hz), 127.93, 126.26, 124.50, 121.11, 118.36, 116.83,
115.82, 115.47 (d, J=86.4 Hz), 102.68. MS (ESI) m/z=325.12
[M þ 1]. HRMS (ESI) calcd for (C16H8O3F4 þ H) 325.0409,
found 325.0409.
30,40-Methylenedioxy-2-methyl-6-ethyl-7-hydroxyisoflavone (101).
A hot solution of 100 (400 mg, 1 mmol) in 5 mL of ethanol
was treated with a 5% NaOH (1 mL), and the mixture was
boiled for 10 min. Then 5 mL water was added and boiling was
continued for another 20 min, after which the mixture was
neutralized with dilute hydrochloric acid to pH 7. The precipi-
tate that deposited was filtered off and crystallized from ethanol
to give 101 as a white solid (240 mg, 68%). 1H NMR (300 MHz,
DMSO): δ 10.78 (s, 1H), 7.70 (s, 1H), 6.95 (d, 1H, J=7.8 Hz),
6.84 (s, 1H), 6.81 (d, 1H, J=1.2 Hz), 6.70 (dd, 1H, J=1.8, 8.1
Hz), 6.05 (s, 2H), 2.62 (q, 2H), 2.22 (s, 3H), 1.15 (t, 3H). 13C
NMR (400 MHz, DMSO): δ 175.30, 162.82, 160.86, 155.74,
147.35, 146.90, 130.08, 127.49, 125.25, 124.34, 122.19, 115.68,
111.45, 108.43, 101.65, 101.40, 22.79, 19.61, 14.30. MS (ESI)
m/z=325.19 [M þ 1]. HRMS (ESI) calcd for (C19H16O5 þ H)
325.0997, found 325.0993.
40-Fluoro-2-methyl-7-hydroxyisoflavone (109). Acetic anhy-
dride (0.77 mL, 4 mmol) was added to a suspension of potassium
carbonate (1.02 g, 4 mmol) and 2-(4-fluorophenyl)-1-(2,4-dihy-
droxyphenyl)ethenone 106 (500 mg, 1 mmol) in DMF (5 mL),
and the resulting suspension heated at 115 °C for 120 min. The
mixture was allowed to cool and poured into water (50 mL), to
give an off-white precipitate. The solids were removed by
filtration and washed with water (50 mL) and diethyl ether (2
ꢀ 5 mL), to give 109 (466 mg, 85%) as a white solid. 1H NMR
(300 MHz, DMSO): δ 11.21 (s, 1H), 7.94 (d, 1H, J=8.7 Hz),
7.42-7.25 (m, 4H), 7.10-6.90 (m, 2H), 2.20 (s, 3H). MS (ESI)
m/z=271.18 [M þ 1]. HRMS (ESI) calcd for (C16H11O3F þ H)
271.0692, found 271.0697.
Ethyl 2-(3-(benzo[d][1,3]dioxol-5-yl)-6-ethyl-2-methyl-4-oxo-
4H-chromen-7-yloxy)-acetate (102). To a solution of 101 (200
mg, 1 mmol)) added ethyl bromoacetate (0.07 mL, 1 mmol) and
K2CO3 (556 mg, 3 mmol) in 5 mL ofDMF, and the mixture was
stirred for 5 h at 90 °C. The reaction mixture extracted twice with
CH2Cl2. The collected organic extracts were dried (Na2SO4),
filtered, and concentrated under reduced pressure. The crude
was crystallized from aqueous ethanol to give 102 as a light-
40-Methoxy-2-methyl-7-hydroxyisoflavone (110). This com-
pound was made using the same procedure as for the prepara-
tion of compound 109 using appropriate starting materials.
1
Yield 76%; off-white solid. H NMR (DMSO, 300 MHz): δ
1
brown solid (220 mg, 87%). H NMR (300 MHz, DMSO): δ
7.84 (d, 1H, J = 8.7 Hz), 7.12 (d, 2H, J = 8.8 Hz), 7.05 (d, 2H, J
= 8.8 Hz), 6.93 (d, 1H, J = 8.7 Hz), 6.81 (s, 1H), 3.83 (s, 3H),
2.25 (s, 3H). MS (ESI) m/z=283.10 [M þ 1]. HRMS (ESI) calcd
for (C17H14O4 þ H) 283.0892, found 283.0894.
7.70 (s, 1H), 6.95 (d, 1H, J=8.3 Hz), 6.82 (s, 1H), 6.80 (d, 1H, J=
1.2 Hz), 6.74 (dd, 1H, J=2.1, 8.2 Hz), 4.78 (s, 2H), 3.91 (q, 2H),
2.78 (q, 2H), 2.26 (s, 3H), 1.30 (t, 3H), 1.25 (t, 3H). MS (ESI)
m/z=411.23 [M þ 1].
3-(2,4-Dihydroxyphenyl)-4-(3,4-methylenedioxy)-1H-pyrazole
(111). Hydrazine hydrate (∼55% aq; 2 mL) was added to a
suspension of ψ-baptigenin 70 (500 mg, 1 mmol) in ethanol
(10 mL) and the mixture heated under reflux for 8 h to give a
brown solution. The solution was allowed to cool and concen-
trated to a pale-yellow solid. The solids were washed with water
to give crude product. The crude product was recrystallized
from boiling toluene, washed with hexane, and dried to give 111
as colorless solid (404 mg, 77%). 1H NMR (300 MHz, DMSO):
δ 12.89 (s, 1H), 9.57 (s, 1H), 9.53 (s, 1H), 7.78 (s, 1H),
6.80-6-45 (m, 6H), 6.02 (s, 2H). MS (ESI) m/z = 297.23
[M þ 1]. HRMS (ESI) calcd for (C16H12N2O4 þ H 297.0797,
found 297.0803.
2-(3-(Benzo[d][1,3]dioxol-5-yl)-6-ethyl-2-methyl-4-oxo-4H-
chromen-7-yloxy)acetic acid (103). To a solution of 102 (200 mg,
1 mmol)) added 2 mL of5% NaOH in 3 mL of ethanol and the
mixture refluxed for 2 h. The reaction mixture was neutralized
with 1 N hydrochloric acid. It was then diluted with water, and
the precipitate that deposited was filtered off and crystallized
1
from ethanol to give 103 as a white solid (111 mg, 60%). H
NMR (400 MHz, DMSO): δ 7.70 (s, 1H), 6.94 (d, 1H, J =
8.4 Hz), 6.79 (d, 1H, J=8.4 Hz), 6.79 (s, 1H), 6.69 (dd, 1H, J=2,
8 Hz), 6.03 (s, 2H), 4.48 (s, 2H), 2.66 (q, 2H), 2.21 (s, 3H), 1.18 (t,
3H, J=7.6 Hz). 13C NMR (400 MHz, DMSO): δ 175.30, 170.89,
163.0, 161.60, 155.87, 147.36, 146.92, 131.06, 127.42, 124.41,
122.34, 116.04, 111.43, 108.44, 101.41, 99.70, 68.11, 22.97, 19.58,
14.26. MS (ESI) m/z=383.27 [M þ 1]. HRMS (ESI) calcd for
(C21H18O7 þ H) 383.1052, found 383.1057.
Compounds 112-115 were made using the same procedure as
for the preparation of compound 111 using appropriate starting
materials.
3-(2,4-Dihydroxyphenyl)-4-(4-fluorophenyl)-1H-pyrazole (112).
Yield 73%; colorless solid. 1H NMR (300 MHz, DMSO): δ
13.31 (s, 1H), 9.69 (s, 1H), 9.54 (s, 1H), 7.86 (s, 1H), 7.27-7.11
(m, 4H), 6.72 (d, 1H, J=8.4 Hz), 6.32 (d, 1H, J=2.2 Hz), 6.13
(dd, 1H, J=2.3, 8.4 Hz). MS (ESI) m/z=271.12 [M þ 1]. HRMS
(ESI) calcd for (C15H11N2O2F þ H) 271.0804, found 271.0806.
2-(4-Fluorophenyl)-1-(2,4-dihydroxyphenyl)ethanone (106).
Resorcinol (1 g, 1 mmol) and 4-fluorophenylacetic acid 104
(1.4 g, 1 mmol) in boron trifluoride etherate (5.68 mL, 0.2 mol)
were heated under a nitrogen atmosphere, at 90°C for 90 min to
give a red solution. The solution was allowed to cool and poured
into aq sodium acetate (10% aq; 30 mL), and the mixture stirred

Article
Journal of Medicinal Chemistry, 2009, Vol. 52, No. 21 6849
3-(2,4-Dihydroxyphenyl)-4-(4-fluorophenyl)-5-trifluoromethyl-
1H-pyrazole (113). Yield 70%; colorless solid. H NMR (300
supported by an Australian Postgraduate Award, and N.G.
was supported by the Endeavor International Postgraduate
Research Scheme. D.H. thanks the Australian Research
Council for funding.
1
MHz, DMSO): δ 13.51 (s, 1H), 9.76 (s, 1H), 9.57 (s, 1H),
7.22-7.12 (m, 4H), 6.74 (d, 1H, J=8.1 Hz), 6.35 (d, 1H, J=
2.4 Hz), 6.15 (dd, 1H, J=2.1, 8.1 Hz). 13C NMR (400 MHz,
DMSO): δ 162.99, 160.57, 159.73, 157.08, 140.35, 138.66 (d, J=
138.4 Hz), 132.11 (t, J=44.4 Hz), 128.44, 126.64, 123.96, 121.28,
117.18, 115.59 (d, J=84.8 Hz), 107.05, 106.49, 103.04, 67.46.
MS (ESI) m/z = 285.08 [M þ 1]. HRMS (ESI) calcd for
(C16H13N2O2F þ H) 285.0961, found 285.0965.
Supporting Information Available: Elemental analysis of
compounds 68-85. This material is available free of charge
via the Internet at http://pubs.acs.org.
3-(2,4-Dihydroxyphenyl)-4-(4-fluorophenyl)-5-methyl-1H-py-
razole (114). Yield 70%; white crystalline solid. 1H NMR
(300 MHz, DMSO): δ 12.94 (s, 1H), 9.51 (s, 1H), 9.40 (s, 1H),
7.24-7.13 (m, 4H), 6.74 (d, 1H, J=8.4 Hz), 6.32-6.02 (m, 2H),
2.16 (s, 3H). MS (ESI) m/z=239.15 [M þ 1]. HRMS (ESI) calcd
for (C16H10N2O2F4 þ H) 239.0678, found 239.0683.
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1
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