Application of Mannich bases to the synthesis of hydroxymethylated isoflavonoids as potential antineoplastic agents

Article abstract of DOI:10.1039/c5ob01828e

The regiospecific Mannich aminomethylation of 7-hydroxyisoflavonoids using bis(N,N-dimethylamino)methane afforded C-8 substituted N,N-dimethylaminomethyl adducts, and the regioselective aminomethylation of 5-hydroxy-7-methoxyisoflavonoids afforded predomi

Full text of DOI:10.1039/c5ob01828e

View Article Online
View Journal
Organic &
Biomolecular
Chemistry
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: M. Frasinyuk, G. P.
Mrug, S. P. Bondarenko, V. M. Sviripa, W. Zhang, X. Cai, M. Fiandalo, J. L. Mohler, C. Liu and D. Watt, Org.
Biomol. Chem., 2015, DOI: 10.1039/C5OB01828E.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the Ethical guidelines still
apply. In no event shall the Royal Society of Chemistry be held
responsible for any errors or omissions in this Accepted Manuscript
or any consequences arising from the use of any information it
contains.
www.rsc.org/obc

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 1 of 10
View Article Online
DOI: 10.1039/C5OB01828E
Journal Name
ARTICLE
Application of Mannich Bases to the Synthesis of
Hydroxymethylated Isoflavonoids As Potential Antineoplastic
Agents
Received 00th January 20xx,
Accepted 00th January 20xx
Mykhaylo S. Frasinyuk,a,b,c Galyna P. Mrug,a Svitlana P. Bondarenko,d Vitaliy M. Sviripa,b,c Wen
DOI: 10.1039/x0xx00000x
Zhang,b,e Xianfeng Cai,b,e Michael V. Fiandalo,f James L. Mohler,f Chunming Liu,b,e and David S.
www.rsc.org/
Wattb,c,e
*
The regiospecific Mannich aminomethylation of 7-hydroxyisoflavonoids using bis(N,N-dimethylamino)methane afforded C-
substituted N,N-dimethylaminomethyl adducts, and the regioselective aminomethylation of 5-hydroxy-7-
8
methoxyisoflavonoids afforded predominantly the C-6 substituted N,N-dimethylaminomethyl adducts. Acetylation of
these C-6 or C-8 Mannich bases with potassium acetate in acetic anhydride provided access to the corresponding
acetoxymethyl derivatives that were subsequently converted to hydroxymethyl- and methoxymethyl-substituted 5-
hydroxy- or 7-hydroxyisoflavonoids related to naturally occurring flavonoids. The C-8 acetoxymethyl, hydroxymethyl or
methoxymethyl-substituted isoflavonoids possessed promising inhibitory potency in the low micromolar range in a
prostate cancer PC-3 cell proliferation assay.
.
in succession, to 5-androsten-3α,17β-diol, testosterone (T)
and DHT. Second, the primary “backdoor” pathway utilizes the
Introduction
conversion of pregnenolone, in several steps, to androsterone
Considerable lore surrounds the health benefits associated
with the consumption of foods rich in natural products in the
isoflavone family. In particular, soy products containing 7-
(AND) and 5α-androstan-3α,17β-diol (DIOL), and the ultimate
conversion of DIOL to DHT. Finally, the secondary “backdoor”
pathway involves the reduction of DHEA to 5-androstene-3,17-
hydroxyisoflavones, such as daidzein (1) and genistein (2)
dione (ASD) and affords, in succession, 5
dione (5
-DIONE) and finally DHT.6-8
α-androstane-3α,17β-
(Figure 1), captured attention for alleged benefits with respect
to cancer prevention and treatment of prostate cancer.1-4
Unfortunately, naturally occurring isoflavones and their
metabolites possess numerous biological activities in addition
to their effects on either androgen receptor expression or
enzymes associated with androgen metabolism.5 Three
pathways operate to produce testicular androgens,
α
testosterone and 5
sterol precursors (Figure 2). First, the “frontdoor” pathway
involves the reduction of pregnenolone to
α-dihydrotestosterone (DHT) from other
dehydroepiandrosterone (DHEA) and the conversion of DHEA,
Figure 1. Naturally occurring 7-hydroxyisoflavones, daidzein (
and genistein ( ), synthetic C-6 or C-8 substituted isoflavonoids
, and 6-(methoxymethyl)eugenin ( ).
1)
2
3
4
The critical, characteristic feature of the two backdoor
pathways is the production of DHT in a route that does not
directly involve testosterone as an intermediate. The backdoor
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 2 of 10
View Article Online
DOI: 10.1039/C5OB01828E
ARTICLE
Journal Name
pathways play a sinister role in producing sufficient DHT to goal for prolonging time-to-relapse for patients who either fail
activate androgen receptors in advanced prostate cancer post-radical prostatectomy or radiation therapy or patients
during androgen-depletion therapy (i.e., medical castration). who present with advanced prostate cancer.
Efforts to interdict these backdoor pathways remain a worthy
Figure 2. Frontdoor (pink), primary backdoor (green) and secondary backdoor (blue) pathways to 5
Enzymes: Cytochrome P450 17A1 or steroid 17 -monooxygenase (CYP17A1); aldo-keto reductase-3 (AKR1C3), 3β-
hydroxysteroid dehydrogenase/Δ5-4 isomerase (3 HSD); 17β-hydroxysteroid dehydrogenase (HSD17B2; HSD17B3); steroid 5
reductase or 3-oxo-5 -hydroxysteroid dehydrogenase (3 OR). Enzymatic
-steroid ꢀ4-dehydrogenase alpha (SRD5A1, 2, 3); 3
reactions are reversible and single arrows were used only for clarity.
α-dihydrotestosterone (DHT).
α
β
α-
α
α
α
As part of a program to develop antineoplastic agents with these natural products were unknown, and the potency was
enzyme targets in the backdoor pathways B and C, we inadequate, in our experience, to launch studies to identify
evaluated isoflavonoids
either position C-6 or C-8 for their activity in a cell-proliferation inhibition at 15 mM concentration in a PC-3 proliferation
assay using castration-resistant9 PC-3 cells. An effect on cell assay. Although these results suggested that
was active
proliferation is, of course, no guarantee that we are inhibiting against a prostate cancer cell line, we required a more potent
the enzymes (Figure 2) in these backdoor pathways. isoflavonoid for studies of the molecular-level target.
3 (Figure 1) with modifications at these targets. An evaluation of genistein (2) showed 74%
2
3
Alternatively, we could have screened libraries against a Reported routes to C-8 substituted isoflavonoids 3b focused
suitable fluorescent-based, specific enzyme assay or screened on the hydrolysis of 8-bromomethyl analogs,17 but these
libraries using a computational model of the active site of a starting materials were not readily available in an efficient
suitable dehydrogenase. Absent these assays, which are under process. As a consequence, we required a synthetic route to
development, or an X-ray structure involving co-crystallization either C-6 or C-8 substituted 7-hydroxyisoflavonoids
3 (Figure
of a dehydrogenase with an isoflavone, we turned to a cell- 1), and we employed a proliferation assay using a prostate
proliferation assay. Our past experience along these same lines cancer PC-3 cell line for probing structure-activity (SAR)
in developing inhibitors that affect Wnt signaling encouraged relationships. We now report on these SAR studies that served
these efforts.10,11
Apart from general literature reports1-4 on the toxicity of in setting the stage for the identification of the molecular
isoflavones, we noted that genistein ( ) displayed IC50 values in target(s) of these isoflavonoids.
the 15-100 M range against different cancer cell lines and 8-
(methoxymethyl)eugenin ( ) (Figure 1), which is a related
as a necessary first step in identifying potent isoflavonoids and
2
ꢁ
4
natural product in the chromone family,12-16 showed
cytotoxicity in P388 leukemia cells.16 The molecular targets of
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 3 of 10
View Article Online
DOI: 10.1039/C5OB01828E
Journal Name
ARTICLE
hydroxylated and 7-hydroxyated isoflavonoids underwent the
desired aminomethylations using bis(N,N-
dimethylamino)methane and exhibited regioselectivity in the
C-5 hydroxylated cases in favor of the C-6
(dimethylamino)methyl derivatives and regiospecificity in the
C-7 hydroxylated cases in favor of the C-8
(dimethylamino)methyl derivatives
Results and discussion
In accord with reported applications of the aminomethylation
reaction to phenols18-25 and
β
-naphthols,26-34 heating
hydroxylated
isoflavonoids
with
bis(N,N-
6
7
dimethylamino)methane in either 1,4-dioxane or isopropanol
furnished the desired N,N-dialkylaminomethyl-substituted
derivatives. Synthesis of appropriate starting materials
involved the regioselective methylation of the C-7 hydroxy
group in 5,7-dihydroxy-2’-methoxy or 4’-methoxyisoflavonoids
to afford 5-hydroxy-2’,7-dimethoxyisoflavone (5a) or 4’,7-di-O-
.
R4O
Me2N
O
R1
R2
methylgenistein35
presence of
(
5b) (Scheme 1) using dimethyl sulfate in the
carbonate.36
R3
O
potassium The 5,7-
R4O
O
O
R1
R2
6a, 6b
a or b
dihydroxyisoflavonoids underwent bis-aminomethylation
reactions,37-39 and the C-5 hydroxylated isoflavonoids 5a and
5b underwent the Mannich reaction to give a mixture of the C-
CH2NMe2
O
R4O
R1
R3
6 and C-8 mono-aminomethylation products 6a-6b and 7a-7b
,
5a - 5e
respectively, in which the C-6 isomer predominated (Scheme
1). The structures of these isomers were established by HMBC
NMR spectroscopy. The 6-(N,N-dimethylamino)methyl
derivatives 6a and 6b have cross-peaks for H-2 with C-8a and
for H-8 with C-8a. Similar cross-peaks were observed for H-2
with C-8a and for the methylene protons at C-8 with C-8a in
compounds 7a and 7b. Heating individual isomers 6b or 7b
with bis(N,N-dimethylamino)methane in 1,4-dioxane failed to
cause their interconversion, unlike the interconversions
reported in a related chromone system.40
R2
R3
7a - 7e
O
a R1 = H, R2 = C6H4OMe-2, R3 = OH, R4 = Me
b R1 = H, R2 = C6H4OMe-4, R3 = OH, R4 = Me
c R1 = H, R2 = C6H4OMe-2, R3 = R4 = H
d R1 = H, R2 = C6H4OMe-4, R3 = R4 = H
e R1 = Me, R2 = C6H4OMe-4, R3 = R4 = H
Scheme 1. Aminomethylation reaction of C-5 or C-7
monohydroxylated isoflavonoids . Legend: a, CH2(NMe)2, i-
PrOH, reflux, b, CH2(NMe2)2, 1,4-dioxane, reflux.
5
The C-7 hydroxyated isoflavonoids 5c-5e underwent Mannich
reactions to give exclusively the C-8 substituted N,N-
dimethylamino derivatives 7c-7e. In summary, both 5-
Scheme 2. Conversion of N,N-dimethylaminomethyl derivatives
6 and 7 to acetoxymethyl, hydroxymethyl and methoxymethyl
derivatives. Legend: a, Ac2O, KOAc; b, 0.2M H2SO4, aq. 1,4-dioxane; c, HCl, MeOH; d, NaOH, MeOH.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 4 of 10
View Article Online
DOI: 10.1039/C5OB01828E
Journal Name
ARTICLE
Direct conversion of the N,N-dimethylaminomethyl derivatives Aphanomyces cochiolides,12 and could be useful for the
and to the corresponding C-6 or C-8 hydroxymethyl synthesis for various hydroxymethyl and alkoxymethyl
derivatives 9 and 12 respectively in basic media or direct derivatives of natural phenolic compounds.
6
7
transformation 6 and 7 to the corresponding C-6 or C-8
methoxymethyl derivatives in refluxing methanol41 proceeded Table 1. Percent inhibition of prostate cancer PC-3 cell
in poor yields. An alternate route to these derivatives involved proliferation by isoflavonoids.
heating
acetate to afford the corresponding diacetates
excellent yield (Scheme 2). Hydrolysis of the diacetates
using a 2:1 ratio of 0.2M aqueous sulfuric acid in 1,4-dioxane
furnished the corresponding hydroxymethyl derivatives or
12, respectively, and hydrolysis of or 11 using hydrochloric
6
or
7
with acetic anhydride in presence of potassium
and 11 in
or 11
8
Inhibition at
10 M (%)
Isoflavonoid C-6 or C-8 Substituent
8
ꢁ
9
8a
6-acetoxymethyl
6-acetoxymethyl
6-hydroxymethyl
6-hydroxymethyl
6-methoxymethyl
6-methoxymethyl
8-acetoxymethyl
8-acetoxymethyl
8-acetoxymethyl
8-acetoxymethyl
8-hydroxymethyl
8-hydroxymethyl
8-hydroxymethyl
8-hydroxymethyl
8-methoxymethyl
8-methoxymethyl
8-methoxymethyl
8-methoxymethyl
17.1 ± 5.9
51.7 ± 5.7
14.6 ± 3.2
0 ± 16.0
8
8b
acid in methanol led directly to the C-6 or C-8-methoxymethyl
derivatives 10 and 13, respectively. The substitution of ethanol
or isopropanol for methanol led to other alkoxymethyl-
substituted analogs (see Supplementary Material). Treatment
of 8-hydroxymethyl derivatives with hydrochloric acid in
methanol furnished to the 8-methoxymethyl analogs and
treatment of 8-acetoxymethyl derivatives 11 with sodium
hydroxide in methanol led to the 8-methoxymethyl analogs 13
(Scheme 2).
9a
9b
10a
10b
11b
11c
11d
11e
12b
12c
12d
12e
13a
13b
13c
13d
53.4 ± 8.0
0 ± 27.0
20.2 ± 2.0
20.6 ± 3.8
99.2 ± 0.4
98.2 ± 1.5
79.5 ± 3.6
0 ± 16.0
99.5 ± 0.2
99.5 ± 0.5
0 ± 1.3
96.8 ± 0.8
0 ± 7.4
34.9 ± 3.3
Conversion of Mannich bases to the acetoxymethyl derivatives
could occur either by SN2 substitutions by acetate on
protonated Mannich bases or by elimination-addition
sequences via an intermediate ortho- or para-quinone
methides. To test the latter suggestion, we treated the
Mannich base 7d with acetic anhydride and potassium acetate
in the presence of 3,4-dihydro-2H-pyran under conditions
where 7d could afford either the diacetate 11d or the inverse
Scheme 3. Mechanistic considerations for the conversion of
Mannich base 7d to diacetate 11d. Legend: a, 3,4-dihydro-2H-
pyran, Ac2O, KOAc; b, 3,4-dihydro-2H-pyran, DMF, heat.
It should be notice, the developed procedures allow us to
synthesize naturally occurring isoflavone 9a (Cristatein) which
is known as a host-specific attractant towards the zoospores of
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 4
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 5 of 10
Journal Name
View Article Online
DOI: 10.1039/C5OB01828E
ARTICLE
electron-demand Diels-Alder adduct 14d. We did not observe hydroxymethyl and methoxymethyl derivatives 12,13c-e via
any of the Diels-Alder adduct 14, an authentic sample of which intermediate ortho-quinone methides. Several C-8
was synthesized independently heating the Mannich base 7d acetoxymethyl, hydroxymethyl or methoxymethyl-substituted
with 3,4-dihydro-2H-pyran in refluxing N,N- isoflavonoids possessed promising potency in the low
dimethylformamide. We excluded possible, competitive micromolar range in a PC-3 cell proliferation assay. The
conversion of the Diels-Alder adduct 14d to the diacetate 11d synthesis and application of biotinylated analogs for biological
by demonstrating that treatment of an authentic sample of the target identification will be reported in due course.
Diels-Alder adduct 14d with acetic anhydride and potassium
acetate led to none of the diacetate 11d, and we also
Experimental
demonstrated that treatment of the diacetate 11d with 3,4-
dihydro-2H-pyran led to none of the Diels-Alder adduct 14d
(Scheme 3). The success of the Diels-Alder reaction supported
the intermediacy of an ortho-quinone methide, but evidence
for this intermediate in the conversion of the Mannich base to
the acetoxymethyl derivative in this isoflavonoid system was
equivocal.
1H and 13C NMR spectra were recorded on a Varian 400
spectrometer (at 500 MHz or at 125 MHz, respectively) or on a
Varian 400 spectrometer (at 400 MHz or at 100 MHz,
respectively) in CDCl3 or DMSO-d6. Structures were also
confirmed with HMBC techniques. IR spectra were recorded
on a Bruker Vertex 70 FT/IR spectrometer. Melting points were
determined in open capillarity tubes with a Buchi B-535
apparatus and were uncorrected. Mass spectra were obtained
with an Agilent 1100 spectrometer under chemical ionization
conditions. Column chromatography was performed using
Macherey-Nagel Silica 60, 0.04-0.063 mm silica gel.
A screening program using PC-3 prostate cancer cells revealed
that several 7-hydroxyisoflavonoids
1 with C-8 acetoxymethyl,
hydroxymethyl or alkoxymethyl substituents exhibited
antineoplastic activity in the 1-10 micromolar range (Table 1).
We observed that C-8 substituted analogs 11
more potent at 10 M concentrations than the C-6 substituted
analogs and 10, respectively. Within the C-8 series, the
, 12 and 13 were
ꢁ
General procedure for the synthesis of isoflavones 5a and 5b.
The procedure of Kim36 was repeated using 5 mmol of 5,7-
dihydroxy-3-(2-methoxyphenyl)-4H-chromen-4-one39 or 5,7-
dihydroxy-3-(4-methoxyphenyl)-4H-chromen-4-one,39 2.07
8, 9
acetoxymethyl- and hydroxymethyl- isoflavonoids were more
potent than the corresponding alkoxymethyl-substituted
isoflavonoids.
g
(15 mmol) of anhydrous potassium carbonate and 0.5 mL (5.2
mmol) of dimethyl sulfate in 10 mL of acetone for 6 h to afford
5a or 5b, respectively.
Also within the C-8 series, the isoflavonoids that possessed a 4-
methoxyphenyl group were in general preferable to those with
a 2-methoxyphenyl group. For example, isoflavonoids 11d and
5-Hydroxy-7-methoxy-3-(2-methoxyphenyl)-4H-chromen-4-
one (5a). Pale yellow solid (89% yield); mp 153-154oC; IR (KBr):
νmax 2993, 2942, 2839, 1662, 1583, 1495, 1439, 1260, 1181,
748 cm-1; 1H NMR (400 MHz, DMSO-d6): δ 3.79 (s, 3H, 2'-
OCH3). 3.88 (s, 3H, 7-OCH3), 6.33 (s, 1H, 6-H), 6.49 (s, 1H, 8-H),
6.94-7.07 (m, 2H, 3', 5'-Н), 7.20-7.28 (m, 1H, 6'-Н), 7.32-7.41
(m, 1H, 4'-Н), 8.06 (s, 1H, 2-H), 12.76 ppm (s, 1H, 5-OH); 13C
NMR (100 MHz, DMSO-d6): δ 55.54, 56.06, 92.50, 98.06,
105.25, 111.29, 119.56, 120.13, 120.73, 129.99, 131.55,
155.59, 157.42, 157.52, 161.59, 165.24, 179.90 ppm; MS (CI):
m/z 299.2 (MH+, 100). Anal. Calcd. for C17H14O5: C, 68.45; H,
4.73. Found: C, 68.12; H, 4.97.
11e were more potent than 11c; isoflavonoids 12b, 12d and
12e were more potent than 12c; and isoflavonoid 13b was
more potent than 13c. Other substituents than methoxy
groups on the 3-phenyl group were also explored (data not
shown) but produced inactive isoflavonoids with few
exceptions. Finally, within the C-8 series, those isoflavonoids
with 7-hydroxy substituents as well as either 8-acetoxymethyl
or 8-hydroxymethyl groups (e.g., 11d and 11e, 12d and 12e)
were in general more potent than isoflavonoids with 5-
hydroxy-7-methoxy groups (e.g., 8b and 9b). The isoflavonoid
11d with a C-8 acetoxymethyl emerged as a promising lead
structure since it retained potency even at
concentration.
1 mM
5-Hydroxy-7-methoxy-3-(4-methoxyphenyl)-4H-chromen-4-
one (5b). Pale yellow solid (73% yield); mp 142-143oC (lit4 mp
141-142oC); IR (KBr): νmax 2964, 2936, 2833, 1658, 1618, 1579,
1516, 1244, 1192, 1151, 1051 cm-1; 1H NMR (400 MHz, DMSO-
d6): δ 3.79 (s, 3H, 4'-OCH3). 3.86 (s, 3H, 7-OCH3), 6.41 (d, 1H, J =
Conclusions
In summary, the Mannich reaction of C-5 or C-7 hydroxylated 2.2 Hz, 8-H), 6.65 (d, 1H, J = 2.2 Hz, 6-H), 7.00 (d, 2H, J = 8.8 Hz,
isoflavonoids provided N,N-(dimethylamino)methyl derivatives 3', 5'-H), 7.51 (d, 2H, J = 8.7 Hz, 2', 6'-H), 8.44 (s, 1H, 2-H),
that were readily converted to acetoxymethyl, hydroxymethyl, 12.92 ppm (s, 1H, 5-OH); 13C NMR (101 MHz, DMSO-d6): δ
or
alkoxymethyl-substituted
isoflavonoids.
The
5- 55.14, 56.06, 92.40, 98.03, 105.37, 113.68, 122.13, 122.73,
hydroxyisoflavonoids 5a,5b afforded C-6 Mannich bases 6a,6b 130.11, 154.61, 157.45, 159.17, 161.70, 165.21, 180.25 ppm;
regioselectively that led via the diacetates 8a,8b to the C-6 MS (CI): m/z 299.1 (MH+, 100). Anal. Calcd. for C17H14O5: C,
hydroxymethyl and methoxymethyl derivatives 9-10a,b 68.45; H, 4.73. Found: C, 68.73; H, 4.94.
presumabley via intermediate ortho-quinone methides. General procedure for the synthesis of Mannich bases 6a-6b
Analogous reactions of the 7-hydroxyisoflavonoids 5c-5e and 7a-7b. To a suspension of 2 mmol of 5a or 5b in 10 mL of
afforded the C-8 Mannich bases 7c-7e regiospecifically, and 1,4-dioxane was added 1.36 mL (10 mmol) of bis(N,N-
the diacetates 11c-11e derived from these Mannich bases dimethylamino)methane. The mixture was refluxed for 24-30
underwent substitutions leading to the desired C-8 h, cooled and concentrated. The mixture of isomeric Mannich
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 6 of 10
View Article Online
DOI: 10.1039/C5OB01828E
ARTICLE
Journal Name
bases 6a-6b and 7a-7b was separated by chromatography dimethylamino)methane. The mixture was heated at 80oC for
using 1:50 methanol-dichloromethane.
4-6 h and was either cooled to induce crystallization or
concentrated and then triturated with hexane to induce
6-[(Dimethylamino)methyl]-5-hydroxy-7-methoxy-3-(2-
methoxyphenyl)-4H-chromen-4-one (6a). Pale yellow solid crystallization of 7c-7e that were recrystallized from
(48% yield); mp 130-131oC; IR (KBr): νmax 2937, 2809, 2759, isopropanol-hexane.
1
1659, 1585, 1457, 1282, 1222, 1120, 1078 cm-1; H NMR (400 8-[(Dimethylamino)methyl]-7-hydroxy-3-(2-methoxyphenyl)-
MHz, CDCl3): δ 2.31 (s, 6H, N(CH3)2), 3.52 (s, 2H, 6-CH2), 3.81 (s, 4H-chromen-4-one (7c). Pale yellow solid (91% yield); mp 120 -
1
3H, 2'-OCH3), 3.92 (s, 3H, 7-OCH3), 6.43 (s, 1H, 8-H), 6.97-7.06 121oC; H NMR (400 MHz, CDCl3): δ 2.43 (s, 6H, N(CH3)2), 3.81
3
(m, 2H, 3', 5'-H), 7.28-7.32 (m, 1H, 6-H'), 7.35-7.42 (m, 1H, 4'- (s, 3H, 2'-OCH3), 3.99 (s, 2H, 8-CH2), 6.89 (d, 1H, J = 8.8 Hz, 6-
H), 7.87 (s, 1H, 2-H), 13.12 ppm (s, 1H, 5-OH); 13C NMR (101 H), 6.96-7.06 (m, 2H, 3', 5'-H), 7.29-7.40 (m, 2H, 4', 6'-H), 7.88
MHz, CDCl3): δ 45.42, 49.70, 55.71, 56.17, 89.45, 106.06, (s, 1H, H-2), 8.19 (d, 1H, 3J = 8.8 Hz, 5-H), 12 ppm (br. s, 1H, 7-
109.83, 111.25, 119.66, 120.57, 121.37, 130.05, 131.58, OH); 13C NMR (125 MHz, CDCl3): δ 44.41, 54.87, 55.20, 107.27,
154.11, 157.37, 157.45, 160.53, 164.22, 180.42 ppm; MS (CI): 113.80, 115.44, 116.89, 124.22, 124.32, 126.67, 130.00,
m/z 356.2 (MH+, 100). Anal. Calcd. for C20H21NO5: C, 67.59; H, 151.25, 154.96, 159.41, 163.97, 175.74 ppm; IR (KBr): νmax
5.96; N, 3.94. Found: C, 67.87; H, 6.17; N, 4.17.
3448, 2951, 1626, 1427, 1246, 1178, 1028 cm-1; MS (CI): m/z
326.2 (MH+, 100). Anal. Calcd.for C19H19NO4: C, 70.14; H, 5.89;
6-[(Dimethylamino)methyl]-5-hydroxy-7-methoxy-3-(4-
methoxyphenyl)-4H-chromen-4-one (6b). Pale yellow solid N, 4.30. Found: C, 70.27; H, 5.77; N, 4.17.
(69% yield); mp 140-142oC; IR (KBr): νmax 2933, 2817, 2757, 8-[(Dimethylamino)methyl]-7-hydroxy-3-(4-methoxyphenyl)-
1
1653, 1610, 1514, 1254, 1221, 1123, 832 cm-1; H NMR (400 4H-chromen-4-one (7d). Pale yellow solid (83% yield); mp 174-
MHz, CDCl3): δ 2.31 (s, 6H, N(CH3)2), 3.53 (s, 2H, 6-CH2), 3.85 (s, 176oC; IR (KBr): νmax 3448, 2951, 1626, 1427, 1246, 1178, 1028
3H, 4'-OCH3), 3.92 (s, 3H, 7-OCH3), 6.42 (s, 1H, 8-H), 6.98 (d, cm-1; 1H NMR (400 MHz, CDCl3): δ 2.44 (s, 6H, N(CH3)2), 3.85 (s,
3
2H, J = 8.8 Hz, 3', 5'-H), 7.46 (d, 2H, J = 8.8 Hz, 2', 6'-H), 7.88 (s, 3H, 4'-OCH3), 3.99 (s, 2H, 8-CH2), 6.90 (d, 1H, J = 8.8 Hz, 6-H),
3
3
1H, 2-H), 13.10 ppm (s, 1H, 5-OH); 13C NMR (101 MHz, CDCl3): 6.97 (d, 2H, J = 8.8 Hz, 3', 5'-H), 7.50 (d, 2H, J = 8.8 Hz, 2', 6'-
3
δ 45.38, 49.65, 55.27, 56.15, 89.41, 105.96, 109.81, 114.00, H), 7.89 (s, 1H, 2-H), 8.14 (d, 1H, J = 8.8 Hz, 5-H), 10.21 ppm
122.95, 123.77, 130.04, 152.32, 157.30, 159.67, 160.55, (br. s, 1H, 7-OH); 13C NMR (125 MHz, CDCl3): δ 44.41, 54.87,
164.29, 180.69 ppm; MS (CI): m/z 356.3 (MH+, 100). Anal. 55.20, 107.27, 113.80, 115.44, 116.89, 124.22, 124.32, 126.67,
Calcd. for C20H21NO5; C, 67.59; H, 5.96; N, 3.94. Found: C, 130.00, 151.25, 154.96, 159.41, 163.97, 175.74 ppm; MS (CI):
67.42; H, 6.14; N, 4.23.
m/z 326.1 (MH+, 100). Anal. Calcd.for C19H19NO4: C, 70.14; H,
8-[(Dimethylamino)methyl]-5-hydroxy-7-methoxy-3-(2-
5.89; N, 4.30. Found: C, 69.88; H, 5.97; N, 4.39.
methoxyphenyl)-4H-chromen-4-one (7a). Pale yellow solid 8-[(Dimethylamino)methyl]-7-hydroxy-3-(4-methoxyphenyl)-
(25% yield); mp 92-93oC; IR (KBr): νmax 2924, 2853, 1654, 1583, 2-methyl-4H-chromen-4-one (7e). Pale yellow solid (91%
1
1460, 1312, 1200, 1083, 1017 cm-1; H NMR (400 MHz, CDCl3): yield); mp 185-187oC (decomp); IR (KBr): νmax 3450, 2958,
δ 2.32 (s, 6H, N(CH3)2), 3.62 (s, 2H, 8-CH2), 3.82 (s, 3H, 2'- 1626, 1603, 1255, 1176, 1016 cm-1; 1H NMR (400 MHz, CDCl3):
OCH3), 3.92 (s, 3H, 7-OCH3), 6.45 (s, 1H, 6-H), 6.98-7.06 (m, 2H, δ 2.30 (s, 3H, 2-CH3), 2.44 (s, 6H, N(CH3)2), 3.84 (s, 3H, 4'-
3', 5'-H), 7.29-7.32 (m, 1H, 6'-H), 7.36-7.42 (m, 1H, 4'-H), 7.94 OCH3), 3.98 (s, 2H, 8-CH2), 6.85 (d, 1H, 3J = 8.8 Hz, 6-H), 6.97 (d,
3
3
(s, 1H, 2-H), 13.12 ppm (s, 1H, 5-OH); 13C NMR (101 MHz, ): δ 2H, J = 8.7 Hz, 3', 5'-H), 7.20 (d, 2H, J = 8.7 Hz, 2', 6'-H), 8.04
43.66, 49.05, 55.70, 56.45, 95.23, 105.73, 111.21, 119.04, (d, 1H, J = 8.8 Hz, 5-H), 11.30 ppm (br. s, 1H); 13C NMR (125
3
120.57, 121.19, 130.23, 131.54, 154.62, 156.14, 157.40, MHz, CDCl3): δ 19.28, 44.44, 54.85, 55.21, 106.83, 113.78,
163.89, 164.02, 180.67 ppm; MS (CI): m/z 356.3 (MH+, 100). 115.03, 115.89, 122.51, 125.33, 126.74, 131.51, 154.68,
Anal. Calcd. for C20H21NO5: C, 67.59; H, 5.96; N, 3.94. Found: C, 158.99, 161.76, 163.69, 176.47 ppm; MS (CI): m/z 340.1 (MH+,
67.83; H, 6.21; N, 4.13.
100). Anal. Calcd.for C20H21NO4: C, 70.78; H, 6.24; N, 4.13.
Found: C, 70.91; H, 5.95; N, 4.33.
8-[(Dimethylamino)methyl]-5-hydroxy-7-methoxy-3-(4-
methoxyphenyl)-4H-chromen-4-one (7b). Pale yellow solid General procedure for the synthesis of diacetates 8a-8b or
(28% yield); mp 126-127oC; IR (KBr): νmax 2934, 2832, 1653, 11a-11e. A mixture of a Mannich base 6a-6b or 7a-7e (2 mmol)
1
1578, 1513, 1298, 1248, 1200, 1178, 1039 cm-1; H NMR (400 and 200 mg (2 mmol) of potassium acetate in 5 mL of acetic
MHz, CDCl3): δ 2.30 (s, 6H, N(CH3)2), 3.58 (s, 2H, 8-CH2), 3.84 (s, anhydride was refluxed for 5 min and cooled to room
3H, 4'-OCH3), 3.92 (s, 3H, 7-OCH3), 6.44 (s, 1H, 6-H), 6.98 (d, temperature. The mixture was diluted with water to afford a
2H, J = 8.8 Hz, 3', 5'-H), 7.46 (d, 2H, J = 8.8 Hz, 2', 6'-H), 7.95 (s, precipitate of 8a-8b or 11a-11e, respectively, that was
1H, 2-H), 13.13 ppm (s, 1H, 5-OH); 13C NMR (101 MHz, CDCl3): recrystallized from acetonitrile-water.
δ 45.21, 49.78, 55.23, 56.14, 95.06, 104.76, 105.48, 113.96, 5-Acetoxy-6-(acetoxymethyl)-7-methoxy-3-(2-
122.86, 122.88, 129.97, 152.94, 155.73, 159.62, 162.35, methoxyphenyl)-4H-chromen-4-one (8a). White solid (96%
163.94, 181.16 ppm; MS (CI): m/z 356.3(MH+, 100). Anal. yield); mp 143-145oC; IR (KBr): νmax 2945, 2836, 1767, 1738,
1
Calcd. for C20H21NO5: C, 67.59; H, 5.96; N, 3.94. Found: C, 1650, 1617, 1451, 1280, 1235, 1127 cm-1; H NMR (400 MHz,
67.65; H, 5.77; N, 3.75.
CDCl3): δ 2.04 (s, 3H, C-6 CH2OСOСН3), 2.41 (s, 3H, C-5
General procedure for the synthesis of Mannich bases 7c-7e. OСOСН3), 3.78 (s, 3H, 2'-OCH3), 3.96 (s, 3H, 7-OCH3), 5.21 (br.s,
43,44
To a stirred suspension of 2 mmol of 5c-5e
in 10 mL of 2H, 6-CH2), 6.80 (s, 1H, 8-H), 6.93-7.03 (m, 2H, 3', 5'-H), 7.24-
isopropyl alcohol was added 0.3 mL (2.2 mmol) of bis(N,N- 7.29 (m, 1H, 6'-H), 7.32 – 7.38 (m, 1H, 4'-H), 7.80 ppm (s, 1H, 2-
6 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 7 of 10
Journal Name
View Article Online
DOI: 10.1039/C5OB01828E
ARTICLE
H); 13C NMR (101 MHz, CDCl3): δ 20.85, 21.10, 54.69, 55.68, 383.1 (MH+, 100). Anal. Calcd. for C21H18O7: C, 65.97; H, 4.75.
56.35, 97.13, 111.34, 111.69, 115.90, 120.52, 120.52, 123.43, Found: C, 65.83; H, 4.95.
129.85, 131.67, 150.12, 152.45, 157.40, 158.93, 161.92, 7-(Acetoxy)-8-(acetoxymethyl)-3-(4-methoxyphenyl)-4H-
169.32, 170.80, 174.02 ppm; MS (CI): m/z 413.2 (MH+, 100). chromen-4-one (11d). Pale yellow soldi (84% yield); mp 141-
Anal. Calcd. for C22H20O8: C, 64.08; H, 4.89. Found: C, 64.27; H, 143oC; IR (KBr): νmax 3076, 1759, 1741, 1660, 1255, 1236 and
5.11.
1178 cm-1; 1H NMR (400 MHz, CDCl3): δ 2.07 (s, 3H, C-8
5-Acetoxy-6-(acetoxymethyl)-7-methoxy-3-(4-
CH2OCOCH3), 2.40 (s, 3H, C-7 OCOCH3), 3.85 (s, 3H, 4'-OCH3)
3
methoxyphenyl)-4H-chromen-4-one (8b). White solid (97% 5.39 (s, 2H, 8-CH2), 6.99 (d, 2H, J = 8.8 Hz, 3', 5'-H), 7.21 (d,
yield); mp 167-169oC; IR (KBr): νmax 2962, 2834, 1734, 1629, 1H, J = 8.8 Hz, 6-H), 7.51 (d, 2H, J = 8.8 Hz, 2', 6'-H), 8.06 (s,
3
3
1
1513, 1453, 1248, 1182, 1123 cm-1; H NMR (400 MHz, CDCl3): 1H, 2-H), 8.36 ppm (d, 1H, 3J = 8.8 Hz, 5-H); 13C NMR (125 MHz,
δ 2.04 (s, 3H, C-6 CH2OСOСН3), 2.44 (s, 3H, C-5 OСOСН3), 3.83 CDCl3): δ 20.69, 20.78, 54.45, 55.29, 114.02, 117.51, 120.30,
(s, 3H, 4'-OCH3), 3.96 (s, 3H, 7-OCH3), 5.20 (s, 2H, 6-CH2), 6.80 122.53, 123.46, 125.15, 128.05, 130.02, 152.27, 153.64,
(s, 1H, 8-H), 6.94 (d, 2H, J = 8.8 Hz, 3', 5'-H), 7.39 (d, 2H, J = 8.8 155.37, 159.77, 168.62, 170.51, 175.59 ppm; MS (CI): m/z
Hz, 2', 6'-H), 7.81 ppm (s, 1H, 2-H); 13C NMR (101 MHz, CDCl3): 383.1 (MH+, 100). Anal. Calcd. for C21H18O7: C, 65.97; H, 4.75.
δ 20.83, 21.08, 54.62, 55.25, 56.35, 97.06, 111.53, 113.91, Found: C, 66.21; H, 4.51.
116.01, 123.58, 125.95, 130.25, 150.18, 150.85, 158.88, 7-(Acetoxy)-8-(acetoxymethyl)-3-(4-methoxyphenyl)-2-
159.58, 162.00, 169.38, 170.77, 174.40 ppm; MS (CI): m/z methyl-4H-chromen-4-one (11e). White crystals (77% yield);
413.2 (MH+, 100). Anal. Calcd. for C22H20O8: C, 64.08; H, 4.89. mp 142-144oC; IR (KBr): νmax 2922, 1765, 1737, 1645, 1223,
1
Found: C, 63.89; H, 5.17.
1199, 1180 cm-1; H NMR (400 MHz, CDCl3): δ 2.08 (s, 3H, C-8
5-Acetoxy-8-(acetoxymethyl)-7-methoxy-3-(2-
CH2OCOCH3), 2.36 (s, 3H, 2-CH3), 2.39 (s, 3H, C-7 OCOCH3),
methoxyphenyl)-4H-chromen-4-one (11a). White solid (98% 3.85 (s, 3H, 4'-OCH3), 5.40 (s, 2H, 8-CH2), 6.98 (d, 2H, 3J = 8.3Hz,
yield); mp 116-118oC; IR (KBr): νmax 2946, 1759, 1652, 1537, 3', 5'-H), 7.16 (d, 1H, J = 8.8 Hz, 6-H), 7.21 (d, 2H, J = 8.3 Hz,
1389, 1254, 1157, 1022 cm-1; 1H NMR (400 MHz, CDCl3): δ 2.09 2', 6'-H), 8.28 ppm (d, 1H, 3J = 8.8 Hz, 5-H); 13C NMR (125 MHz,
(s, 3H, C-8 CH2OCOCH3), 2.40 (s, 3H, C-5 OCOCH3), 3.79 (s, 3H, CDCl3): δ 19.45, 20.72, 20.78, 54.55, 55.24, 113.93, 117.08,
2'-OCH3), 3.96 (s, 3H, 7-OCH3), 5.36 (s, 2H, 8-CH2), 6.67 (s, 1H, 119.84, 121.51, 123.30, 124.57, 127.94, 131.42, 153.46,
6-H), 6.94-7.10 (m, 2H, 3', 5'-H), 7.24-7.29 (m, 1H, 6'-H), 7.24 – 154.92, 159.22, 163.21, 168.66, 170.50, 176.11 ppm; MS (CI):
7.28 (m, 1H, 4'-H), 7.86 ppm (s, 1H, 2-H); 13C NMR (101 MHz, m/z 397.2 (MH+, 100). Anal. Calcd. for C22H20O7: C, 66.66; H,
CDCl3): δ 20.74, 20.98, 54.38, 55.39, 56.12, 103.49, 109.19, 5.09. Found: C, 66.41; H, 5.27.
3
3
110.93, 111.38, 119.87, 120.18, 122.50, 129.53, 131.34, General procedures for the synthesis of hydroxymethyl
151.37, 152.36, 156.56, 156.99, 161.36, 169.18, 170.72, 173.95 derivatives 9 and 12. A solution of 8 or 11 (1 mmol) in 10 mL
ppm; MS (CI): m/z 413.2 (MH+, 100). Anal. Calcd. for C22H20O8: of 1,4-dioxane and 20 mL of 0.2 M aqueous sulfuric acid was
C, 64.08; H, 4.89. Found: C, 64.32; H, 5.07.
heated at 50-60oC for 6-8 h. The mixture was cooled and
diluted with water, and the resulting precipitate was collected
5-Acetoxy-8-(acetoxymethyl)-7-methoxy-3-(4-
methoxyphenyl)-4H-chromen-4-one (11b). White solid (88% by filtration. The crude product was chromatographed using 1-
yield); mp 124-126oC; IR (KBr): νmax 2943, 2840, 1763, 1740, 20 methanol-dichloromethane to afford
9 or 12 that was
1
1645, 1515, 1411, 1304, 1247, 1182, 1026 cm-1; H NMR (400 recrystallized from acetonitrile.
MHz, CDCl3): δ 2.09 (s, 3H, C-8 CH2OCOCH3), 2.44 (s, 3H, C-5 5-Hydroxy-6-(hydroxymethyl)-7-methoxy-3-(2-
OCOCH3), 3.84 (s, 3H, 4'-OCH3), 3.97 (s, 3H, 7-OCH3), 5.37 (s, methoxyphenyl)-4H-chromen-4-one (9a). White solid (25%);
2H, 8-CH2), 6.68 (s, 1H, 6-H), 6.96 (d, 2H, J = 8.8 Hz, 3', 5'-H), mp 100-101oC; IR (KBr): νmax 2938, 2837, 1654, 1583, 1494,
7.41 (d, 2H, J = 8.8 Hz, 2', 6'-H), 7.87 ppm (s, 1H, 2-H); 13C NMR 1283, 1220, 1129, 1076 cm-1; 1H NMR (400 MHz, CDCl3): δ 3.81
(101 MHz, CDCl3): δ 20.95, 21.21, 54.57, 55.28, 56.41, 103.95, (s, 3H, 2'-OCH3), 3.93 (s, 3H, 7-OCH3), 4.81 (s, 2H, 6-CH2OH),
109.54, 111.61, 113.97, 123.49, 125.46, 130.27, 151.07, 6.43 (s, 1H, 8-H), 6.94-7.08 (m, 2H, 3', 5'-H), 7.27-7.45 (m, 2H,
151.86, 156.91, 159.63, 161.83, 169.59, 171.02, 174.73 ppm; 4', 6'-H), 7.88 (s, 1H, 2-H), 13.19 ppm (s, 1H, 5-OH); 13C NMR
MS (CI): m/z 413.3 (MH+, 100). Anal. Calcd. for C22H20O8: C, (101 MHz, CDCl3): δ 53.71, 55.70, 56.07, 89.67, 106.18, 111.24
64.08; H, 4.89. Found: C, 63.85; H, 4.61.
(111.92), 119.37, 120.57, 121.38, 130.15, 131.54, 154.40,
7-(Acetoxy)-8-(acetoxymethyl)-3-(2-methoxyphenyl)-4H-
157.40, 157.57, 159.90, 163.20, 180.53 ppm; MS (CI): m/z
chromen-4-one (11c). White solid (98% yield); mp 122-124oC; 329.1 (MH+, 100). Anal. Calcd. for C18H16O6: C, 65.85; H, 4.91.
IR (KBr): νmax 3076, 1759, 1741, 1660, 1255, 1236 and 1178 cm- Found: C, 65.93; H, 5.07.
1
1; H NMR (400 MHz, CDCl3): δ 2.08 (s, 3H, C-8 CH2OCOCH3), 5-Hydroxy-6-(hydroxymethyl)-7-methoxy-3-(4-
2.40 (s, 3H, C-7 OCOCH3), 3.82 (s, 3H, 2'-OCH3) 5.40 (s, 2H, 8- methoxyphenyl)-4H-chromen-4-one (9b). White solid (37%
3
CH2), 6.97-7.07 (m, 2H, 3', 5'-H), 7.21 (d, 1H, J = 8.8 Hz, 6-H), yield); mp 138-139oC; IR (KBr): νmax 2930, 2833, 1645, 1611,
7.30-7.35 (m, 1H, 6'-H), 7.37-7.42 (m, 1H, 4'-H), 8.04 (s, 1H, H- 1513, 1253, 1223, 1179, 836 cm-1; 1H NMR (400 MHz, CDCl3): δ
2), 8.35 ppm (d, 1H, 3J = 8.8 Hz, 5-H); 13C NMR (125 MHz, 3.80 (s, 3H, 4'-OCH3), 3.92 (s, 3H, 7-OCH3), 4.48 (s, 2H, 6-
CDCl3): δ 20.70, 20.79, 54.46, 55.29, 114.03, 117.52, 120.31, CH2OH), 6.74 (s, 1H, 8-H), 6.96-7.05 (m, 2H, 3', 5'-H), 7.47-7.58
122.54, 123.47, 125.16, 128.06, 130.03, 152.28, 153.65, (m, 2H, 2', 6'-H), 8.48 (s, 1H, 2-H), 13.23 ppm (s, 1H, 5-OH); 13
C
155.38, 159.77, 168.63, 170.52, 175.59 ppm; MS (CI): m/z NMR (101 MHz, CDCl3): δ 53.68, 55.31, 56.08, 89.65, 106.12,
111.99, 114.07, 122.73, 123.84, 130.04, 152.57, 157.53,
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 7
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 8 of 10
View Article Online
DOI: 10.1039/C5OB01828E
ARTICLE
Journal Name
159.80, 159.98, 163.34, 180.83 ppm; MS (CI): m/z (%): 329.2 collected by filtration. The products 10 and 13 were purified by
(MH+, 100). Anal. Calcd. for C18H16O6: C, 65.85; H, 4.91. Found: chromatography using 1:20 methanol-dichloromethane.
C, 65.56; H, 4.87.
5-Hydroxy-7-methoxy-6-(methoxymethyl)-3-(2-
5-Hydroxy-8-(hydroxymethyl)-7-methoxy-3-(4-
methoxyphenyl)-4H-chromen-4-one (10a). White solid (53%
methoxyphenyl)-4H-chromen-4-one (12b). White solid (48% yield); mp 123-124oC; IR (KBr): νmax 2934, 2880, 1656, 1585,
yield); mp 139-141oC; IR (KBr): νmax 2938, 2835, 1656, 1610, 1494, 1450, 1284, 1220, 1137, 1078 cm-1; H NMR (400 MHz,
1
1582, 1514, 1250, 1178, 1040, 831 cm-1; 1H NMR (400 MHz, DMSO-d6): δ 3.23 (s, 3H, 6-CH2OCH3), 3.75 (s, 3H, 2'-OCH3),
CDCl3): δ 3.85 (s, 3H, 4'-OCH3), 3.96 (s, 3H, 7-OCH3), 4.86 (s, 2H, 3.93 (s, 3H, 7-OCH3), 4.41 (s, 2H, 6-CH2OCH3), 6.78 (s, 1H, 8-H),
3
8-CH2OH), 6.44 (s, 1H, 6-H), 6.99 (d, 2H, J = 8.8 Hz, 3', 5'-H), 6.94-7.09 (m, 2H, 3', 5'-H), 7.28-7.34 (m, 1H, 6'-H), 7.35-7.43
7.46 (d, 2H, 3J = 8.8 Hz, 2', 6'-H), 7.94 (s, 1H, 2-H), 13.14 ppm (s, (m, 1H, 4'-H), 8.37 (s, 1H, 2-H), 13.24 (s, 1H, 5-OH); 13C NMR
1H, 5-OH); 13C NMR (101 MHz, CDCl3): δ 56.35, 55.36, 56.25, (101 MHz, CDCl3): δ 55.70, 56.17, 58.14, 61.58, 89.56, 106.10,
95.22, 105.56, 106.97, 114.08, 122.70, 123.29, 130.03, 152.66, 109.02, 111.26, 119.49, 120.57, 121.46, 130.12, 131.53,
154.91, 159.76, 163.03, 163.56, 181.11 ppm; MS (CI): m/z 154.23, 157.43, 157.99, 160.95, 164.22, 180.45; MS (CI): m/z
329.2 (MH+, 100). Anal. Calcd. for C18H16O6: C, 65.85; H, 4.91. 343.3 (MH+, 100). Anal. Calcd. for C19H18O6: C, 66.66; H, 5.30.
Found: C, 65.68; H, 5.11.
Found: C, 66.58; H, 5.17.
7-Hydroxy-8-(hydroxymethyl)-3-(2-methoxyphenyl)-4H-
5-Hydroxy-7-methoxy-6-(methoxymethyl)-3-(4-
chromen-4-one (12c). White crystals (63% yield); mp 163- methoxyphenyl)-4H-chromen-4-one (10b). White solid (95%
165oC; IR (KBr): νmax 2953, 1627, 1603, 1441, 1267, 1237 cm-1; yield); mp 180-181oC; IR (KBr): νmax 2969, 2835, 1655, 1622,
1
1H NMR (400 MHz, DMSO-d6): δ 3.71 (s, 3H, 2'-OCH3), 4.72 (s, 1579, 1516, 1264, 1225, 1138, 1097 cm-1; H NMR (400 MHz,
3
2H, 8-CH2OH), 6.82 (d, 1H, J = 8.8 Hz, 6-H), 6.95-7.02 (m, 1H, DMSO-d6): δ 3.24 (s, 3H, 6-CH2OCH3), 3.81 (s, 3H, 4'-OCH3),
5'-H), 7.04-7.10 (m, 1H, 3'-H), 7.19-7.25 (m, 1H, 6'-H ), 7.32- 3.93 (s, 3H, 7-OCH3), 4.43 (s, 2H, 6-CH2OCH3), 6.74 (s, 1H, 8-H),
3
3
3
7.39 (m, 1H, 4'-H), 7.75 (d, 1H, J = 8.8 Hz, 5-H), 8.12 ppm (s, 7.01 (d, 2H, J = 8.8 Hz, 3', 5'-H), 7.53 (d, 2H, J = 8.8 Hz, 2', 6'-
1H, H-2); 13C NMR (125 MHz, DMSO-d6): δ 51.39, 55.13, H), 8.46 (s, 1H, 2-H), 13.29 ppm (s, 1H, 5-OH); 13C NMR (101
113.60, 114.59, 114.87, 116.60, 122.88, 124.25, 125.91, MHz, DMSO-d6): δ 55.16, 56.50, 57.28, 60.84, 90.31, 105.06,
130.06, 153.10, 155.85, 158.94, 160.51, 174.86 ppm; MS (CI): 108.41, 113.72, 122.33, 122.68, 130.17, 154.67, 157.45,
m/z (%) 299.2 (MH+, 100). Anal. Calcd. for C17H14O5: C, 68.45; 159.22, 159.97, 164.11, 180.40 ppm; MS (CI): m/z 343.2 (MH+,
H, 4.73. Found: C, 68.55; H, 4.93.
100). Anal. Calcd. for C19H18O6: C, 66.66; H, 5.30. Found: C,
66.87; H, 5.56.
7-Hydroxy-8-(hydroxymethyl)-3-(4-methoxyphenyl)-4H-
chromen-4-one (12d). White crystals (69% yield); mp 150- 5-Hydroxy-7-methoxy-8-(methoxymethyl)-3-(2-
152oC (decomp); IR (KBr): νmax 2953, 1627, 1603, 1441, 1267, methoxyphenyl)-4H-chromen-4-one (13a). White solid (28%
1237 cm-1; 1H NMR (400 MHz, DMSO-d6): δ 3.79 (s, 3H, 4'- yield); mp 154-155oC; IR (KBr): νmax 2922, 2835, 1664, 1558,
1
OCH3), 4.70 (s, 2H, 8-CH2), 4.91 (br s, 1H, 8-CH2OH), 6.95-7.05 1377, 1311, 1285, 1239, 1095, 1031 cm-1; H NMR (400 MHz,
(m, 3H, 6, 3', 5'-H), 7.52 (d, 2H, 3J = 8.8 Hz, 2', 6'-H), 7.93 (d, 1H, DMSO-d6): δ 3.25 (s, 3H, 8-CH2OCH3), 3.74 (s, 3H, 2'-OCH3),
3J = 8.8 Hz, 5-H), 8.41 (s, 1H, 2-H), 10.77 ppm (s, 1H, 7-OH); 13
C
3.93 (s, 3H, 7-OCH3), 4.51 (s, 2H, 8-CH2OCH3), 6.61 (s, 1H, 6-H),
NMR (125 MHz, DMSO-d6): δ 51.39, 55.13, 113.60, 114.59, 6.98 – 7.05 (m, 1H, 5'-H), 7.07-7.15 (m, 1H, 3'-H), 7.24-7.31 (m,
114.87, 116.60, 122.88, 124.25, 125.91, 130.06, 153.10, 1H, 6'-H), 7.36-7.44 (m, 1H, 4'-H), 8.37 (s, 1H, 2-H) , 13.14 ppm
155.85, 158.94, 160.51, 174.86 ppm; MS (CI): m/z (%) 299.1 (s, 1H, 5-OH); 13C NMR (101 MHz, DMSO-d6): δ 55.51, 56.49,
(MH+, 100). Anal. Calcd. for C17H14O5: C, 68.45; H, 4.73. Found: 57.23, 60.89, 95.23, 104.03, 104.45, 111.23, 119.37, 120.04,
C, 68.72; H, 4.58.
120.28, 129.88, 131.45, 155.31, 155.56, 157.29, 162.04,
163.65, 180.10 ppm; MS (CI): m/z 343.3 (MH+, 100). Anal.
7-Hydroxy-8-(hydroxymethyl)-3-(4-methoxyphenyl)-2-
methyl-4H-chromen-4-one (12e). White crystals (58% yield); Calcd. for C19H18O6; C, 66.66; H, 5.30. Found: C, 66.93; H, 5.12.
mp 212-214oC (decomp); IR (KBr): νmax 2958, 1633, 1589, 1438, 5-Hydroxy-7-methoxy-8-(methoxymethyl)-3-(4-
1
1246, 1066 cm-1; H NMR (400 MHz, DMSO-d6): δ 2.28 (s, 3H, methoxyphenyl)-4H-chromen-4-one (13b). White solid (41%
2-CH3), 3.79 (s, 3H, 4'-OCH3), 4.71 (s, 2H, 8-CH2), 4.89 (br. s, 1H, yield); mp 126-128oC; IR (KBr): νmax 2938, 2838, 1662, 1610,
1
8-CH2OH), 6.92-7.05 (m, 3H, 6, 3', 5'-H), 7.19 (d, 2H, 3J = 8.8 Hz, 1585, 1541, 1246, 1204, 1072, 1042 cm-1; H NMR (400 MHz,
2', 6'-H), 7.82 (d, 1H, 3J = 8.8 Hz, 5-H), 10.68 ppm (s, 1H, 7-OH); DMSO-d6): δ 3.25 (s, 3H, 8-CH2OCH3), 3.79 (s, 3H, 4'-OCH3),
13C NMR (125 MHz, DMSO-d6): δ 19.18, 51.48, 55.02, 113.43, 3.92 (s, 3H, 7-OCH3), 4.50 (s, 2H, 8-CH2OCH3), 6.60 (s, 1H, 6-H),
114.13, 114.55, 115.51, 121.43, 125.33, 125.64, 131.62, 7.01 (d, 2H, J = 8.8 Hz, 3', 5'-H), 7.52 (d, 2H, J = 8.8 Hz, 2', 6'-H),
155.27, 158.47, 160.30, 162.37, 175.19 ppm; MS (CI): m/z (%) 8.51 (s, 1H, 2-H), 13.24 ppm (s, 1H, 5-OH); 13C NMR (101 MHz,
313.1 (MH+, 100). Anal. Calcd. for C18H16O5: C, 69.22; H, 5.16. DMSO-d6): δ 55.16, 56.53, 57.28, 60.92, 95.30, 103.96, 104.65,
Found: C, 68.95; H, 5.31.
General procedures for the synthesis of alkoxymethyl 162.36, 163.81, 180.64 ppm; MS (CI): m/z 343.3 (MH+, 100).
derivatives 10 and 13. A mixture of diacetate or 11 (2 mmol) Anal. Calcd. for C19H18O6: C, 66.66; H, 5.30. Found: C, 66.43; H,
113.72, 121.85, 122.66, 130.17, 154.76, 155.38, 159.19,
8
and 0.1 mL of concentrated hydrochloric acid in 10 mL of 5.22.
methanol was refluxed for 16-24 h. The mixture was cooled 7-Hydroxy-8-(methoxymethyl)-3-(2-methoxyphenyl)-4H-
and diluted with water, and the resulting precipitate was chromen-4-one (13c). White crystals (78% yield); mp 164-166
1
OC; IR (KBr): νmax 2937, 1624, 1579, 1427, 1284, 1259 cm-1; H
8 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 9 of 10
Journal Name
View Article Online
DOI: 10.1039/C5OB01828E
ARTICLE
NMR (400 MHz, DMSO-d6): δ 3.29 (s, 3H, 8-CH2OCH3), 3.71 (s, PC-3 prostate cancer cells were cultured in DMEM/F-12 HAM
3H, 2'-OCH3), 4.62 (s, 2H, 8-CH2OCH3), 6.91-7.02 (m, 2H, 6, 5'- Mixture (Sigma D8437), 10% Fetal Bovine Serum (Atlanta
H), 7.04-7.10 (m, 1H, 3'-H), 7.20-7.24 (m, 1H, 6'-H ), 7.33-7.40 Biological S11150). Before the treatment, 3.5x104 cells per well
3
(m, 1H, 4'-H), 7.82 (d, 1H, J = 8.8 Hz, 5-H), 8.17 ppm (s, 1H, H- were split into 12-well plates. After 24 h, 10
ꢁ
M of each
2); 13C NMR (125 MHz, DMSO-d6): δ 55.07, 57.45, 61.37, compound was added to each well. DMSO was used as a
111.24, 113.55, 114.45, 116.53, 122.95, 124.13, 126.70, control. This experiment was done in triplicate. Cell viability
130.01, 153.03, 156.16, 158.92, 161.10, 174.71 ppm; MS (CI): and number were analyzed using Vi-Cell XR Cell Viability
m/z 313.2 (MH+, 100). Anal. Calcd. for C18H16O5: C, 69.22; H, Analyzer (Beckman Coulter).
5.16. Found: C, 68.88; H, 5.27.
7-Hydroxy-8-(methoxymethyl)-3-(4-methoxyphenyl)-4H-
Acknowledgements
chromen-4-one (13d). White crystals (89% yield); mp 167-
169oC decomp; IR (KBr): νmax 2937, 1624, 1579, 1427, 1284,
1259 cm-1; 1H NMR (400 MHz, DMSO-d6): δ 3.30 (s, 3H, 8-
CH2OCH3), 3.79 (s, 3H, 4'-OCH3), 4.62 (s, 2H, 8-CH2OCH3), 6.99
DSW and CL were supported by R21 CA139359 and CA172379
from the NIH, by the Office of the Dean of the College of
Medicine, and by NIH Grant Number P20 RR020171 from the
National Institute of General Medical Sciences to L. Hersh, PI.
The contents are solely the responsibility of the authors and
do not necessarily represent the official views of the NIH or
the NIGMS.
3
3
(d, 2H, J = 8.8 Hz, 3', 5'-H), 7.05 (d, 1H, J = 8.8 Hz, 6-H), 7.53
3
3
(d, 2H, J = 8.8 Hz, 2', 6'-H), 7.98 (d, 1H, J = 8.8 Hz, 5-H), 8.40
(s, 1H,2-H), 10.83 ppm (s, 1H, 2-H) ppm; 13C NMR (125 MHz,
DMSO-d6): δ 55.07, 57.45, 61.37, 111.24, 113.55, 114.45,
116.53, 122.95, 124.13, 126.70, 130.01, 153.03, 156.16,
158.92, 161.10, 174.71 ppm; MS (CI): m/z 313.1 (MH+, 100).
Anal. Calcd. for C18H16O5: C, 69.22; H, 5.16. Found: C, 69.01; H,
4.92.
Notes and references
DSW and CL own shares in two limited liability corporations committed to
developing new antineoplastic agents patented by the University of Kentucky. The
other authors declare no competing financial interests.
7-Hydroxy-8-(methoxymethyl)-3-(4-methoxyphenyl)-2-
methyl-4H-chromen-4-one (13e). White crystals (89% yield);
mp 215-217oC decomp; IR (KBr): νmax 2927, 1614, 1585, 1406,
1294, 1246, 1065 cm-1; 1H NMR (400 MHz, DMSO-d6): δ 2.27 (s,
3H, 2-CH3), 3.29 (s, 3H, 8-CH2OCH3), 3.79 (s, 3H, 4'-OCH3), 4.61
1.
I. C. Munro, M. Harwood, J. J. Hlywka, A. M. Stephen, J.
Doull, W. G. Flamm and H. Adlercreutz, Nutr. Rev., 2003,
61, 1-33.
3
2.
3.
H. Adlercreutz, Scand. J. Clin. Lab. Invest., 1990, 50, 3-23.
S. Andres, K. Abraham, K. E. Appel and A. Lampen, Crit.
Rev. Toxicol. , 2011, 41, 463-506.
(s, 2H, 8-CH2OCH3), 6.98 (d, 2H, J = 8.8 Hz, 3', 5'-H), 7.00 (d,
3
3
1H, J = 8.8 Hz, 6-H), 7.20 (d, 2H, J = 8.8 Hz, 2', 6'-H), 7.87 (d,
1H, 3J = 8.8 Hz, 5-H), 10.85 ppm (s, 1H) ppm; 13C NMR (125
MHz, DMSO-d6): δ 19.13, 55.01, 57.48, 61.40, 110.99, 113.41,
114.03, 115.43, 121.52, 125.21, 126.48, 131.60, 155.70,
158.48, 160.89, 162.25, 175.08 ppm; MS (CI): m/z 327.1 (MH+,
100). Anal. Calcd. for C19H18O5: C, 69.93; H, 5.56. Found: C,
70.23; H, 5.28.
4.
5.
E. Miadoková, Interdiscip. Toxicol., 2009, 2, 211-218.
J. M. Hamilton-Reeves, S. A. Rebello, W. Thomas, J. W.
Slaton and M. S. Kurzer, J. Nutr., 2007, 137, 1769-1775.
J. L. Mohler, C. W. Gregory, O. H. Ford, D. Kim, C. M.
Weaver, P. Petrusz, E. M. Wilson and F. S. French, Clin.
Cancer Res., 2004, 10, 440-448.
6.
3-(4-Methoxyphenyl)-10,11,11a,12-tetrahydro-4
dipyrano[2,3- :2',3'- ]chromen-4-one (14d). To a solution of
2 mmol of 7d in 10 mL of DMF was added 2 mL (22 mmol, 11
eq) of 2 ,3,4ꢀdihydropyran. The solution was refluxed for 24ꢀ
40 h. The solvent and excess 2 ,3,4ꢀdihydropyran were
evaporated in vacuo and the residue was purified by
H,7aH,9H-
7.
M. A. Titus, M. J. Schell, F. B. Lih, K. B. Tomer and J. L.
Mohler, Clin. Cancer Res., 2005, 11, 4653-4657.
M. V. Fiandalo, J. Wilton and J. L. Mohler, Int. J. Biol. Sci. ,
2014, 10, 596-601.
S. Tai, Y. Sun, J. M. Squires, H. Zhang, W. K. Oh, C.-Z. Liang
and J. Huang, Prostate, 2011, 71, 1668-1679.
W. Zhang, V. Sviripa, X. Chen, J. Shi, T. Yu, A. Hamza, N. D.
Ward, L. M. Kril, C. W. Vander Kooi, C.-G. Zhan, B. M.
Evers, D. S. Watt and C. Liu, ACS Chem. Biol., 2013, 8, 796-
803.
V. M. Sviripa, W. Zhang, A. G. Balia, O. V. Tsodikov, J. R.
Nickell, F. Gizard, T. Yu, E. Y. Lee, L. P. Dwoskin, C. Liu and
D. S. Watt, J. Med. Chem., 2014, 57, 6083-6091.
Y. Wen, M. T. Islam and S. Tahara, Biosci. Biotechnol.
Biochem., 2006, 70, 2567-2570.
N. Tanaka, T. Murakami, H. Wada, A. B. Gutierrez, Y. Saiki
and C. Chen, Chem. Pharm. Bull., 1985, 33, 5231-5238.
L. E. C. Suarez and F. D. Monache, Phytochemistry, 1992,
31, 2481-2482.
b
f
8.
H
9.
H
,
10.
chromatography with1:50 methanolꢀdichloromethane. Pale
yellow solid (30% yield); mp 182ꢀ183oC; IR (KBr) νmax 2966,
2933, 1636, 1598, 1511, 1437, 1248, 1205, 1178, 1090, 1029
1
cmꢀ1; H NMR (400 MHz, CDCl3) δ 1.47ꢀ1.92 (m, 4H, 10, 11ꢀ
11.
CH2), 2.24ꢀ2.40 (m, 1H, 11aꢀCH), 2.90 (dd, 1H, 2J = 17.4 Hz,
3J = 4.2 Hz, 12αꢀCH), 3.01 (dd, 1H, 2 = 17.4, 3
J J = 6.1 Hz, 12βꢀ
CH), 3.75ꢀ3.82 (m, 1H, 9αꢀCH), 3.85 (s, 3H, 4'ꢀOMe), 3.95ꢀ
12.
13.
14.
15.
16.
4.09 (m, 1H, 9βꢀCH), 5.44 (d, 1H, 3J = 2.0 Hz, 7aꢀСH), 6.93ꢀ
7.02 (m, 3H, 6, 3', 5'ꢀH), 7.50 (d, 2H, 3
J = 8.7 Hz, 2', 6'ꢀH), 7.96
(s, 1H, 2ꢀH), 8.10 ppm (d, 1H, 3J = 8.8 Hz, 5ꢀH); 13C NMR
(400 MHz, CDCl3) δ 23.17, 23.57, 24.02, 30.62, 55.33, 62.58,
96.94, 107.86, 113.94, 115.27, 118.45, 124.19, 124.79, 125.29,
130.13, 151.79, 155.37, 157.15, 159.55, 176.07 ppm; MS (CI):
m/z 365.1 (MH+, 100). Anal. Calcd for C22H20O5: C, 72.51; H,
5.53. Found: C, 72.38; H, 5.67.
C. Mahidol, H. Prawat, W. Kaweetripob and S. Ruchirawat,
Heterocycles, 2002, 57, 1287-1292.
Y. Feng, J. W. Blunt, A. L. J. Cole and M. H. G. Munro, J.
Nat. Prod., 2002, 65, 1681-1682.
Cell Proliferation Assay
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 9
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 10 of 10
View Article Online
DOI: 10.1039/C5OB01828E
ARTICLE
Journal Name
17.
Y. Chen, M. Cheng, F.-Q. Liu, P. Xia, K. Qian, D. Yu, Y. Xia,
Z.-Y. Yang, C.-H. Chen, S. L. Morris-Natschke and K.-H. Lee,
Eur. J. Med. Chem., 2011, 46, 4924-4936.
J. P. Phillips and E. M. Barrall, J. Org. Chem., 1956, 21,
692-694.
F. F. Blicke and F. J. McCarty, J. Org. Chem., 1959, 24,
1061-1069.
J. H. Burckhalter, J. N. Wells and W. J. Mayer, Tetrahedron
Lett., 1964, 5, 1353-1359.
A. R. Katritzky, X. Lan and J. N. Lam, Chem. Ber., 1991,
124, 1809-1817.
Y. Omura, Y. Taruno, Y. Irisa, M. Morimoto, H. Saimoto
and Y. Shigemasa, Tetrahedron Lett., 2001, 42, 7273-7275.
J.-J. Lin and S.-F. Lin, J. Coll. Interf. Sci., 2003, 258, 155-
162.
J. R. Farrell, J. Niconchuk, C. S. Higham and B. W.
Bergeron, Tetrahedron Lett., 2007, 48, 8034-8036.
M. Minakawa, H.-M. Guo and F. Tanaka, J. Org. Chem.,
2008, 73, 8669-8672.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
M. Betti, Gazz. Chim. Ital., 1900, 30, 301-309.
M. Betti, Gazz. Chim. Ital., 1900, 30, 310-316.
M. Betti, Gazz. Chim. Ital., 1906, 36, 392-394.
L. O. Paqett, Encyclopedia of Reagents for Organic
Synthesis, Wiley, UK, 1995.
30.
31.
32.
M. Arend, B. Westermann and N. Risch, Angew. Chem. Int.
Ed., 1998, 37, 1044-1070.
C. Cardellicchio, G. Ciccarella, F. Naso, F. Perna and P.
Tortorella, Tetrahedron, 1999, 55, 14685-14692.
C. Cardellicchio, M. A. M. Capozzi and F. Naso,
Tetrahedron Asymm., 2010, 21, 507-517.
I. Szatmari and F. Fulop, Curr. Org. Syn., 2004, 1, 155-165.
C. de Graaff, E. Ruijter and R. V. A. Orru, Chem. Soc. Rev.,
2012, 41, 3969-4009.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
A. C. Talukdar, N. Jain, S. De and H. G. Krishnamurty,
Phytochemistry, 2000, 53, 155-157.
U. B. Kim, D. P. Furkert and M. A. Brimble, Org. Lett.,
2013, 15, 658-661.
S. P. Bondarenko, M. S. Frasinyuk and V. P. Khilya, Chem.
Nat. Compd., 2012, 48, 26-29.
S. P. Bondarenko and M. S. Frasinyuk, Chem. Nat. Compd.,
2013, 49, 841-844.
S. P. Bondarenko, A. V. Levenets, M. S. Frasinyuk and V. P.
Khilya, Chem. Nat. Compd., 2003, 39, 271-275.
P. J. Houghton and Y. Hairong, Planta Med., 1985, 51, 23-
27.
J. Li, G. Wang, M. Dong and Q. Zhang, Bioorg. Med. Chem.
Lett., 2011, 21, 2324-2326.
F. E. King, M. F. Grundon and K. G. Neill, J. Chem. Soc.,
1952, 36, 4580-4584.
M. S. Frasinyuk, S. P. Bondarenko, V. P. Khilya, C. Liu, D. S.
Watt and V. M. Sviripa, Org. Biomol. Chem., 2015, 13,
1053-1067.
44.
M. S. Frasinyuk, S. P. Bondarenko and V. P. Khilya, Chem.
Nat. Compd., 2006, 42, 142-147.
10 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins