The preparation of new isoflavones

Article abstract of DOI:10.1081/SCC-100104346

The synthesis of ten new isoflavones in good yield is described. The method, involving intermediate 2-hydroxybenzyl ketones, did not require protection of the hydroxyl groups of the starting polyphenols.

Full text of DOI:10.1081/SCC-100104346

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THE PREPARATION OF NEW ISOFLAVONES
Silvia Sepúlveda-Boza a , Gool Hasan Walizei b , Marcos Caroli Rezende a , Yesseny
Vásquez a , Carolina Mascayano a & Lorenzo Mejías a
a Universidad de Santiago, Facultad de Ciencias Médicas, Santiago, Chile
b Institut für Physiologische Chemie der Universität Bonn, Nussallee 11, Bonn,
Deutschland
Available online: 16 Aug 2006
To cite this article: Silvia Sepúlveda-Boza, Gool Hasan Walizei, Marcos Caroli Rezende, Yesseny Vásquez, Carolina
Mascayano & Lorenzo Mejías (2001): THE PREPARATION OF NEW ISOFLAVONES, Synthetic Communications: An International
Journal for Rapid Communication of Synthetic Organic Chemistry, 31:12, 1933-1940
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SYNTHETIC COMMUNICATIONS, 31(12), 1933–1940 (2001)
THE PREPARATION OF NEW
ISOFLAVONES
Silvia Sepulveda-Boza,a, Gool Hasan Walizei,b
*
Marcos Caroli Rezende,c Yesseny Vasquez,c
Carolina Mascayano,c and Lorenzo Mejıasc
aFacultad de Ciencias Medicas, Universidad de Santiago,
Santiago, Chile
bInstitut fur Physiologische Chemie der Universitat Bonn,
Nussallee 11, Bonn, Deutschland
cFacultad de Quımica y Biologıa, Universidad de Santiago,
Santiago, Chile
ABSTRACT
The synthesis of ten new isoflavones in good yield is described.
The method, involving intermediate 2-hydroxybenzyl ketones,
did not require protection of the hydroxyl groups of the start-
ing polyphenols.
Flavonoids and isoflavonoids have found a wide range of applications
as natural antioxidants1–5 being suggested in the diet as agents responsible
for the prevention of coronary diseases,6,7 breast8 and prostate cancer.9
Such applications stress the interest in the preparation of new members of
this class of compounds.
Isoflavones are generally prepared by two major routes, starting from
2-hydroxyphenylbenzylketones or from chalcones.
* Corresponding author. E-mail: ssepulve@lauca.usach.cl
1933
Copyright & 2001 by Marcel Dekker, Inc.
www.dekker.com

ORDER
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1934
SEPULVEDA-BOZA ET AL.
In the first case, the 2-hydroxyphenyl ketone is obtained by a standard
electrophilic substitution of a phenol with a benzyl cyanide (Houben-
Hoesch reaction)10 or with an acyl chloride (Friedel-Crafts acylation).11
The resulting hydroxy ketone is cyclised to the isoflavone by a variety of
methods which include treatment with BF3.Et2O/DMF,12 with Zn(CN)2/
HCl,13 with ClCOCO2Et/pyridine, followed by a decarboxylation,14 with
POCl3/DMF,15 or with Me2NCH(OMe)2.16
In the second route, a thallium (III) salt brings about the cyclization,
with concomitant rearrangement, of a 2-hydroxyphenyl chalcone, to form
the corresponding isoflavone.17,18
In the present report we describe the synthesis of ten new isoflavones,
employing the method of Bass12 for ring-closing a 2-hydroxyphenyl aryl
ketone with BF3.Et2O and MeSO2Cl in DMF. The intermediate 2-hydro-
xyphenyl aryl ketones (3) were prepared in good yields from the correspond-
ing phenols and a substituted benzyl cyanide, in a classical Houben-Hoesch
reaction. The formation of the corresponding isoflavones (4) from the crude
intermediates also proceeded in good yields. The final products were char-
acterized by their nmr, uv and high-resolution mass spectra.
EXPERIMENTAL
Melting points were recorded on a Koffler hot-stage apparatus and
were not corrected. Ir spectra were obtained with an SP-1100 Pye Unicam
Spectrometer, UV spectra were recorded on a Cary 17 Varian equipment.
Nmr spectra were obtained with a Bruker WH-90 and with an AC-200 spec-
trometers, employing tetramethylsilane as internal reference. High-resolution
mass spectra were recorded with an MS-30 and an MS-50 A.E.I. equipment.
All reagents and solvents were analytically pure and were purchased
from Merck.
Preparation of Benzylphenylketones (3) (General Procedure) – Dry
HCl was passed into a cooled (0ꢀC), stirred mixture of the substituted
phenylacetonitrile (1) (0.34 mol) and anhydrous zinc chloride (30 g,
0.22 mol) in dry diethyl ether (200 mL). The corresponding polyhydroxy-
benzene (2) (0.28 mol) was added portionwise with constant bubbling of
gaseous HCl for further 4–6 hours. The reaction mixture was then stirred
at room temperature for 4 to 20 hours, until the complete disappearance of
the reagents, as shown by thin-layer chromatography.
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 (1 L) for 4 to 5 hours. The ketone (3) which separated upon cooling,
was filtered and recrystallized in the appropriate solvent.

ORDER
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NEW ISOFLAVONES
1935
In this way, the following ketones (3) were prepared: 2,4-Dihydroxy-
3-methylphenyl-30,40-methylenedioxybenzylketone (3a) – 2,6-Dihydroxy-
toluene and 3,4-methylenedioxyphenylacetonitrile gave product (3a) in
53% yield, crystallized from methanol, mp 164ꢀC. H NMR (DMSO-d6)
1
d 1.95 (3 H, s, Me), 4.17 (2 H, s, benzyl CH2), 5.96 (2 H, s, OCH2O),
6.47 (1 H, d, J ¼ 8.8 Hz, 5-H), 6.74 (1 H, dd, J¼8.0 Hz, J0 ¼ 2.0 Hz, 60-H),
6.83 (1 H, d, J ¼ 8.0 Hz, 50-H), 6.84 (1 H, d, J ¼ 2.0 Hz, 20-H), 7.80
(1 H, d, J ¼ 8.8 Hz, 6-H), 10.53 (1 H, s, 4-OH), 12.95 (1 H, s, 2-OH).
UV (MeOH) ꢀmax 235 and 287 nm.

ORDER
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1936
SEPULVEDA-BOZA ET AL.
2,4-Dihydroxy-3-methylphenyl-30-ethoxycarbonylbenzylketone (3b) –
2,6-Dihydroxytoluene and ethyl 3-(cyanomethyl)benzoate gave a mixture
of ketone (3b) and its carboxylic acid. This mixture was washed with a
5% NaHCO3 solution and the insoluble residue filtered to give product
(3b) with 61% yield, recrystallized from dichloromethane, mp 157ꢀC. H
1
NMR (DMSO-d6) d 1.30 (3 H, t, J ¼ 6.5 Hz, CH3CH2O), 1.96 (3 H, s, 3-
Me), 4.29 (2 H, q, J ¼ 6.5 Hz, CH3CH2O), 4.42 (2 H, s, benzyl CH2), 6.50 (1
H, d, J ¼ 9.0 Hz, 5-H), 7.45 (1 H, t, J ¼ 8.0 Hz, 50-H), 7.55 (1 H, m, 60-H),
7.80–7.90 (3 H, m, 6-H, 40-H and 20-H), 10.62 (1H, s, 4-OH), 12.85 (1 H, s, 2-
OH). UV (MeOH) ꢀmax 233 and 297 nm.
2,4-Dihydroxy-3-methylphenyl-30-trifluoromethylbenzylketone (3c) –
2,6-Dihydroxytoluene and 3-trifluoromethylphenylacetonitrile gave product
(3c) in 79% yield, crystallized from dichloromethane, mp 167ꢀC. H N MR
1
(DMSO-d6) d 2.96 (3 H, s, 3-Me), 4.47 (2 H, s, benzyl CH2), 6.41 (1 H, d,
J ¼ 9.0 Hz, 5-H), 7.54 (1 H, t, J ¼ 8.0 Hz, 50-H), 7.57 (1 H, d, J ¼ 7 Hz, 40-H),
7.61 (1 H, d, J ¼ 7 Hz, 60-H), 7.67 (1H, s, 20-H), 7.85 (1 H, d, J ¼ 9 Hz, 6-H),
10.60 (1H, s, 4-OH), 12.80 (1 H, s, 2-OH). UV (MeOH) ꢀmax 218 and 287 nm.
2,4-Dihydroxy-3-methylphenyl-40-methoxybenzylketone (3d) – 2,6-
Dihydroxytoluene and 4-methoxyphenylacetonitrile gave (3d) with 58%
yield, mp 172–173ꢀC. H NMR (DMSO-d6) d 1.96 (3 H, s, 3-CH3), 3.71
1
(3 H, s, OCH3), 4.20 (2 H, s, benzyl CH2), 6.48 (1 H, d, J ¼ 8.8 Hz, 5-H), 6.89
(2 H, d, J ¼ 8.6 Hz, 30-H and 50-H), 7.21 (2H, d, J ¼ 8.6 Hz, 20-H, and 60-H),
7.84 (1 H, d, J ¼ 8.8 Hz, 6-H), 10.60 (1H, s, 4-OH), 13.01 (1 H, s, 2-OH). 13
C
NMR (DMSO-d6) d 7.38, 42.87, 54.94, 107.17, 110.31, 111.48, 113.81,
127.05, 130.10, 130.30, 157.99, 162.48, 162.70, 202.79.
2,4-Dihydroxy-30-trifluoromethylbenzylketone (3e) – 1,3-Dihydroxy-
benzene and 3-trifluoromethylphenylacetonitrile gave (3e) with 60% yield,
mp 165ꢀC. H NMR (DMSO-d6) d 4.44 (2 H, s, benzyl CH2), 6.33 (1 H, d,
1
J ¼ 2.0 Hz, 3-H), 6.44 (1 H, dd, J ¼ 9.0 Hz, J0 ¼ 2.0 Hz, 5-H), 7.55–7.71 (4H,
m, 20-H, 40-H, 50-H and 60-H), 7.95 (1 H, d, J ¼ 9.0 Hz, 6-H), 10.74 (1H, s,
4-OH), 12.40 (1 H, s, 2-OH). UV (MeOH) ꢀmax 232, 277 and 315 nm.
2,4,5-Trihydroxy-30-trifluoromethylbenzylketone(3f) – 1,2,4-Trihydroxy-
benzene and 3-trifluoromethylphenylacetonitrile gave compound (3f) with
45% yield, mp 170ꢀC. H NMR (DMSO-d6) d 4.42 (2 H, s, benzyl CH2),
1
6.34 (1 H, s, 3-H), 7.35 (1 H, s, 6-H), 7.52–7.61 (3H, m, 40-H, 50-H and 60-H),
7.65 (1 H, s, 20-H), 8.88 (1 H, s, 5-OH), 10.50 (1H, s, 4-OH), 11.96 (1 H, s,
2-OH).
2,3,4-Trihydroxyphenyl-30,40-methylenedioxybenzylketone (3g) – 1,2,3-
Trihydroxybenzene and 3,4-methylenedioxyphenylacetonitrile gave com-
pound (3g) in 49% yield, mp 125–126ꢀC (ethanol/water). 1H N MR
(DMSO-d6) d 4.20 (2 H, s, benzyl CH2), 6.00 (2 H, s, OCH2O), 6.46 (1 H,
d, J ¼ 8.2 Hz, 5-H), 6.78–6.88 (3 H, m, 20-H, 50-H and 60-H), 7.52 (1 H, d,

ORDER
REPRINTS
NEW ISOFLAVONES
1937
J ¼ 8.2 Hz, 6-H), 8.67 (1 H, s, 3-OH), 10.16 (1 H, s, 4-OH), 12.56 (1 H, s,
2-OH). UV (MeOH) ꢀmax 238 and 290 nm.
2,3,4-Trihydroxyphenyl-30-carboxybenzylketone (3h) – 1,2,3-Trihy-
droxybenzene and ethyl 3-cyanomethylbenzoate gave a mixture of ketone
(3h) and its ethyl ester, after acid hydrolysis of the intermediate ketiminium
salt. The carboxyketone was separated by extraction with a 5% NaHCO3
solution, and reprecipitation by addition of concentrated HCl to the filtrate.
The yield of (3h) was 43%, recrystallized from ethanol/water (1:1), mp
222ꢀC. H NMR (DMSO-d6) d 4.43 (2 H, s, benzyl CH2), 6.51 (1 H, d,
1
J ¼ 8.6 Hz, 5-H), 7.37 (1 H, t, J ¼ 8.0 Hz, 50-H), 7.48 (1 H, d, J ¼ 8.0 Hz,
60-H), 7.54 (1 H, d, J ¼ 8.6 Hz, 6-H), 7.82 (1 H, d, J ¼ 8.0 Hz, 40-H), 7.91
(1H, s, 20-H), 8.73 (1 H, s, 3-OH), 10.22 (1 H, s, 4-OH), 12.47 (1 H, s, 2-OH).
UV (MeOH) ꢀmax 235 and 295 nm.
2,3,4-Trihydroxyphenyl-30-trifluoromethylbenzylketone (3i) – 1,2,3-
Trihydroxybenzene and 3-trifluoromethylphenylacetonitrile gave compound
(3i) in 65% yield, after purification by column chromatography (silicagel,
CHCl3: MeOH 10:1 as eluent), mp 171ꢀC. 1H NMR (DMSO-d6) d 4.46 (2 H,
s, benzyl CH2), 6.49 (1 H, d, J ¼ 9.0 Hz, 5-H), 7.53–7.58 (3 H, m, 40-H, 50-H,
60-H), 7.67 (1 H, s, 20-H), 7.72 (1 H, d, J ¼ 9.0 Hz, 6-H), 12.38 (1 H, s
(broad), 2-OH) [signals for the 3-OH and 4-OH not seen].
2,3,4,-Trihydroxyphenyl-40-methoxybenzylketone (3j)
– 1,2,3-Tri-
hydroxybenzene and 4-methoxyphenylacetonitrile gave compound (3j) in
63% yield, mp 158–160ꢀC (ethanol/water 1:1). 1H NMR (DMSO-d6) d
3.72 (3 H, s, OCH3), 4.21 (2 H, s, benzyl CH2), 6.42 (1 H, d, J ¼ 8.9 Hz,
5-H), 6.88 (2 H, d, J ¼ 8.6 Hz, 30-H and 50-H), 7.21 (2 H, d, J ¼ 8.6 Hz, 20-H),
7.50 (1 H, d, J ¼ 8.9 Hz, 6-H), 8.65 (1 H, s, 3-OH), 10.15 (1H, s, 4-OH), 12.59
(1 H, s, 2-OH). 13C NMR (DMSO-d6) 43.36, 55.24, 107.98, 112.68, 114.08,
123.19, 127.32, 130.66, 132.59, 152.78, 152.84, 158.28, 203.37.
Preparation of Isoflavones (4) (General Procedure) – To a solution of
the benzylketone (3) (0.18 mol) in dry DMF (200 mL) was added drop-
wise BF3.Et2O (0.88 mol). To this solution, warmed to 50ꢀC, was slowly
added a solution of methanesulfonyl chloride (0.56 mol) in DMF (100 mL).
The resulting mixture was then heated to 100ꢀC for 2 hours. After cooling, it
was poured into water (4 L) and left overnight to give a precipitate, which
was stirred for 2 hours in cold methanol (50 mL), filtered and crystallized in
the appropriate solvent.
In this way the following isoflavones (4) were prepared: 7-Hydroxy-
8-methyl-30,40-methylenedioxyisoflavone (4a) – The benzylketone (3a) gave
the corresponding isoflavone (4a) in 75% yield, mp 270–272ꢀC. High
Resolution MS: m/z found 296.0680, calculated 296.0682, corresponding to
C17H12O5. 1H NMR (DMSO-d6) d 1.25 (3 H, s, CH3), 6.07 (2 H, s,
OCH2O), 6.93–7.08 (3 H, m, 20-H, 50-H and 60-H), 7.04 (1 H, d,

ORDER
REPRINTS
1938
SEPULVEDA-BOZA ET AL.
J ¼ 8.4 Hz, 6-H), 7.84 (1 H, d, J ¼ 8.4 Hz, 5-H), 8.40 (1 H, s, 2-H), 10.65 (1
H, s, 7-OH). 13C NMR (DMSO-d6) d 7.84, 101.00, 108.00, 109.39, 110.33,
113.34, 116.57, 122.24, 123.71, 125.87, 146.80, 146.93, 153.23, 155.39, 159.96
and 174.93.
7-Hydroxy-8-methyl-30-ethoxycarbonylisoflavone (4b) – The benzyl-
ketone (3b) gave the corresponding isoflavone (4b) in 84% yield,
mp 222ꢀC (from methanol). High Resolution MS: m/z found 324.0980,
1
calculated 324.0998, corresponding to C19H16O5. H NMR (DMSO-d6) d
1.32 (3 H, t, J ¼ 7.5 Hz, CH3CH2O), 2.22 (3 H, s, ArCH3), 4.27 (2 H, q,
J ¼ 7.5 Hz, CH3CH2O), 6.92 (1 H, d, J ¼ 9.0 Hz, 6-H), 7.42 (1 H, t,
J ¼ 8.0 Hz, 50-H), 7.70 (1 H, ddd, J ¼ 8.0 Hz, J0 ¼ 1.8 Hz, J00¼1.5 Hz, 40-H),
7.83 (1 H, d, J ¼ 9.0 Hz, 5-H), 7.92 (1 H, ddd, J ¼ 8.0 Hz, J0 ¼ 1.8 Hz,
J00 ¼ 1.5 Hz, 60-H), 8.05 (1H, s, 2-H), 8.11 (1 H, dd, J ¼ 1.8 Hz, J0 ¼ 1.5 Hz,
20-H), 10.03 (1 H, s, 7-OH). 13C NMR (DMSO-d6) d 7.51, 13.81, 60.38,
111.12, 113.77, 116.60, 122.74, 123.38, 127.84, 128.26, 129.31, 130.01,
132.25, 133.01, 152.61, 155.61, 160.00, 165.60, 175.10. UV (MeOH) ꢀmax
233 and 300 nm.
7-Hydroxy-8-methyl-30-trifluoromethylisoflavone (4c) – The benzyl-
ketone (3c) gave the corresponding isoflavone (4c) in 81% yield, mp
283–284ꢀC (from methanol). High Resolution MS: m/z found 320.0659,
1
calculated 320.0659, corresponding to C17H11O3F3. H NMR (DMSO-d6)
d 2.21 (3 H, s, ArCH3), 7.10 (1 H, d, J ¼ 9.0 Hz, 6-H), 7.64 (1 H, t,
J ¼ 8.0 Hz, 50-H), 7.71 (1 H, d, J ¼ 8.0 Hz, 60-H), 7.83 (1 H, d, J ¼ 9.0 Hz,
5-H), 7.85 (1 H, d, J ¼ 8.0 Hz, 40-H), 7.97 (1 H, s, 20-H), 8.56 (1 H, s, 2-H),
10.68 (1 H, s, 7-OH). UV (MeOH) ꢀmax 243 and 300 nm.
7-Hydroxy-8-methyl-40-methoxyisoflavone (4d) – The benzylketone
(3d) gave the corresponding isoflavone (4d) in 43% yield, mp 272–272ꢀC
(from methanol). High Resolution MS: m/z found 282.0889, calculated
1
282.0886, corresponding to C17H14O4. H NMR (DMSO-d6) d 2.19 (3 H,
s, ArCH3), 3.75 (3 H, s, OCH3), 6.95 (3 H, m, 6-H, 30-H and 50-H), 7.49 (2 H,
d, J ¼ 8.2 Hz, 20-H and 60-H), 7.83 (1 H, d, J ¼ 8.6 Hz, 5-H), 8.35 (1 H, s,
2-H), 10.69 (1 H, s, 7-OH). 13C NMR (DMSO-d6) d 7.52, 54.66, 110.42,
113.12, 113.45, 116.20, 122.24, 123.35, 123.88, 129.62, 152.73, 155.07,
158.45, 159.53 and 174.60.
7-Hydroxy-30-trifluoromethylisoflavone (4e) – The benzylketone (3e)
gave the corresponding isoflavone (4e) in 94% yield, mp 248ꢀC (from metha-
nol). High Resolution MS: m/z found 306.0522, calculated 306.0513,
corresponding to C16H9O3F3. 1H NMR (DMSO-d6) d 6.86 (1 H, d,
J ¼ 2.2 Hz, 8-H), 6.94 (1 H, dd, J ¼ 9.0 Hz, J0 ¼ 2,2 Hz, 6-H), 7.62 (1 H,
t, J ¼ 8.0 Hz, 50-H), 7.70 (1 H, dt, J ¼ 8.0 Hz, J0 ¼ 2.0 Hz, 60-H), 7.85 (1 H,
dt, J ¼ 8.0 Hz, J0 ¼ 2.0 Hz, 40-H), 7.94 (1 H, t, J ¼ 2.0 Hz, 20-H), 7.97 (1H, d,
J ¼ 9.0 Hz, 5-H), 8.49 (1 H, s, 2-H), 10.87 (1 H, s, 7-OH).

ORDER
REPRINTS
NEW ISOFLAVONES
1939
6,7-Dihydroxy-30-trifluoromethylisoflavone (4f) – The benzylketone
(3f) gave the corresponding isoflavone (4f) in 84% yield, mp 274–275ꢀC
(from methanol). High Resolution MS: m/z found 322.0425, calculated
1
322.0439, corresponding to C16H9O4F3. H NMR (DMSO-d6) d 6.93 (1 H,
s, 8-H), 7.41 (1 H, s, 5-H), 7.64 (1 H, t, J ¼ 8.0 Hz, 50-H), 7.70 (1 H, d,
J ¼ 8.0 Hz, 40-H), 7.85 (1 H, d, J ¼ 8.0 Hz, 60-H), 7.97 (1 H, s, 20-H), 8.47
(1 H, s, 2-H).
7,8-Dihydroxy-30,40-methylenedioxyisoflavone (4g) – The benzylketone
(3g) gave the corresponding isoflavone (4g) in 80% yield, mp 260ꢀC (from
ethanol). High Resolution MS: m/z found 298.0480, calculated 298.0478,
corresponding to C16H10O6. 1H NMR (DMSO-d6) d 6.04 (2 H, s, OCH2O),
6.93 (1 H, t, J ¼ 8.0 Hz, 60-H), 6.96 (1 H, d, J ¼ 9.0 Hz, 6-H), 7.08 (1 H, d,
J ¼ 8.0 Hz, 50-H), 7.15 (1 H, s, 20-H), 7.50 (1 H, d, J ¼ 9.0 Hz, 5-H), 8.38 (1 H, s,
2-H), 9.47 (1 H, s, 8-OH), 10.35 (1 H, s, 7-OH). UV (MeOH) ꢀmax 262, 292 nm.
7,8-Dihydroxy-30-carboxyisoflavone (4h) – The benzylketone (3h) gave
the corresponding isoflavone (4h) in 75% yield, mp 313–314ꢀC (from metha-
nol). High Resolution MS: m/z found 298.0475, calculated 298.0478, corres-
pondingtoC16H10O6.1HNMR(DMSO-d6)d6.80(1H,d,J ¼ 9.0 Hz,6-H),7.44
(1 H, d, J ¼ 9.0 Hz, 5-H), 7.55 (1 H, t, J ¼ 7.0 Hz, 50-H), 7.80 (1 H, d, J ¼
8.2 Hz, 60-H), 7.94 (1 H, d, J ¼ 8.2 Hz, 40-H), 8.18 (1 H, s, 20-H), 8.51 (1 H, s,
2-H), 9.51 (1 H, s, 8-OH), 10.37 (1 H, s, 7-OH). UV (MeOH) ꢀmax 258, 301 nm.
7,8-Dihydroxy-30-trifluoromethylisoflavone (4i) – The benzylketone
(3i) gave the corresponding isoflavone (4i) in 79% yield, mp 225ꢀC (from
dichloromethane/methanol (10:1)). High Resolution MS: m/z found
322.0454, calculated 322.0455, corresponding to C16H9O4F3. 1H N MR
(DMSO-d6) d 7.04 (1 H, d, J ¼ 9.0 Hz, 6-H), 7.55 (1 H, d, J ¼ 9.0 Hz,
5-H), 7.71–7.88 (3 H, m, 40-H, 50-H and 60-H), 8.04 (1 H, s, 20-H), 8.64
(1 H , s, 2-H), 10.00 (1 H, broad s, 8-OH) [signal for 7-OH not seen]. UV
(MeOH) ꢀmax 263, 305 nm.
7,8-Dihydroxy-40-methoxyisoflavone (4j) – The benzylketone (3j) gave
the corresponding isoflavone (4j) in 45% yield, mp 253–255ꢀC (from chloro-
form/methanol (10:1)). High Resolution MS: m/z found 284.0676, calcu-
1
lated 284.0668, corresponding to C16H12O5. H NMR (DMSO-d6) d 3.80
(3 H, s, OCH3), 6.98 (3 H, m, 30-H, 50-H and 6-H), 7.50 (3 H, m, 20-H, 60-H
and 5-H), 8.38 (1 H, s, 2-H), 9.50 (1 H, s, 8-OH), 10.35 (1 H, s, 7-OH),
13C NMR (DMSO-d6) d 55.08, 113.53, 114.15, 115.62, 117.41, 122.58,
124.35, 130.04, 132.84, 146.70, 149.95, 152.82, 158.88 and 175.00.
ACKNOWLEDGMENTS
We are grateful to DICYT-USACH for supporting this work.

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SEPULVEDA-BOZA ET AL.
REFERENCES
1. Gyorgy, P.; Murata, K.; Ikehata, H. Nature 1964, 203, 870.
2. Naim, M.; Gestetner, B.; Bondi, A.; Birk, Y. J. Agric. Food Chem.
1976, 24, 1174.
3. Torel, J.; Cillard, J.; Cillard, P. Phytochemistry 1986, 25, 383.
4. Harper, A.; Kerr, D.J.; Gescher, A.; Chipman, J.K. Free Radical Res.
1999, 31, 149.
5. Arora, A.; Nair, M.G.; Strasburg, G.M. Arch. Biochem. Biophys.
1998, 356, 133.
6. Da Re, P.; Verlicchi, L.; Setniker, I. J. Med. Chem. 1966, 10, 266.
7. Nitz, R.E.; Potzsch, E. Arzneim Forsch. 1963, 4, 243.
8. Ito, C.; Itoigawa, M.; Tan, H.T.; Tokuda, H.; Furukawa, H. Cancer
Lett. 2000, 152, 187.
9. Denis, L.; Morton, M.S.; Griffiths, K. Eur. Urol. 1999, 35, 377.
10. Spoerri, P.E.; Du Bois, A.S. Org. Reactions 1945, 5, 387.
11. Baddeley, G.; Holt, G.; Pickles, W. J. Chem. Soc. 1952, 4162.
12. Bass, R.J. J. Chem. Soc. Commun. 1976, 2, 78.
13. Farkas, L.; Major, A.; Pallos, L.; Varady, J. Chem. Ber. 1958, 91, 2858.
14. Baker, W.; Chadderton, J.; Harborne, J.B.; Ollis, W.D. J. Chem. Soc.
1953, 1852.
15. Kegal, S.A.; Nair, P.M.; Venkataraman, K. Tet. Letters 1962, 593.
16. Pelter, A.; Foot, S. Synthesis 1976, 326.
17. Farkas, L.; Gottsegen, A.; Nogradi, M.; Antus, S. J. Chem. Soc. Perkin
Trans. 1 1974, 305.
18. Ollis, W.D.; Ormand, K.L.; Sutherland, I.O. J. Chem. Soc. C 1970, 119.
Received in the USA August 29, 2000

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