A synthesis of cinnamoyloxyisoflavones

Article abstract of DOI:10.1134/S1068162006040121

Interaction of 7-hydroxyisoflavonones with cinnamoyl chloride results in cinnamoyloxyisoflavonones. Pleiades Publishing, Inc., 2006.

Full text of DOI:10.1134/S1068162006040121

ISSN 1068-1620, Russian Journal of Bioorganic Chemistry, 2006, Vol. 32, No. 4, pp. 402–403. © Pleiades Publishing, Inc., 2006.
Original Russian Text © A. Aitmambetov, A.M. Tokhtybaeva, R.T. Tlegenov, L. Tsao, 2006, published in Bioorganicheskaya Khimiya, 2006, Vol. 32, No. 4, pp. 446–447.
A Synthesis of Cinnamoyloxyisoflavones
A. Aitmambetova, A. M. Tokhtybaevaa, R. T. Tlegenovb, and L. Tsaoc
a
Complex Institute of Natural Sciences, Karakalpak Division, Academy of Sciences of Uzbekistan,
pr. Berdakh 41, Nukus, 742000 Uzbekistan
Berdakh Karakalpak State University, ul. Universitetskaya 1, Nukus, 742006 Uzbekistan
b
c
Xianggiang University, Clienlilu/14, Urumchi, 830046 China
Received June 28, 2005; in final form, August 10, 2005
Abstract—Interaction of 7-hydroxyisoflavonones with cinnamoyl chloride results in cinnamoyloxyisofla-
vonones.
DOI: 10.1134/S1068162006040121
Key words: cinnamic acid, isoflavones, synthesis
INTRODUCTION
hepatoprotective, cholagogue, antiatherosclerotic, and
other kinds of activity [1–3].
Among natural flavonoids, including isoflavonoids,
compounds with a complex structure occur, whose
molecules have residues of cinnamic acids. Natural fla-
vonoids were found to contain three common hydroxy-
cinnamic acids and sinapic (3,5-dimethoxy-4-hydroxy-
cinnamic) acid are attached to antocyanidins, whereas
three of them, to carbohydrate fragments of antocyans.
The same wide spectrum of biological activities is
intrinsic of the isoflavanoids with cinnamoyl residues
attached to phenol hydroxyl groups. Therefore, the syn-
thesis of isoflavones esterified at phenol hydroxyls and
close in structure to natural isoflavones is of a particular
interest.
Flavolignans belong to a large class of phenolic nat-
ural compounds classified under a common term
lignoids. They are flavanoid derivatives containing res-
RESULTS AND DISCUSSION
We studied the interaction of 7-hydroxyisoflavones
idues of cinnamic alcohol or other similar fragments (I) and (II) [4, 5] with cinnamoyl chloride in order to
attached to phenol hydroxy groups in ring A or B. Med- obtain 7-cinnamoylisoflavones. As a result, 7-cin-
icines on their basis exert beneficial effect on cardiovas- namoyloxyisoflavones (III) and (IV) were formed as
cular and central nervous systems, have P-vitamin, shown in scheme.
HO
O
R
PhCH CHCOO
O
R
PhCH=CHCOCl
O
O
O
O
O
O
(I) R = Me
(II) R = Et
(III) R = Me
(IV) R = Et
The structures of the compounds were confirmed by
elemental analyses and 1H NMR spectra. In the spectra,
the olefin protons of 7-cinnamoyl substituent appeared
as doublets with spin-coupling constant of 15.5 Hz.
EXPERIMENTAL
2-Alkyl-3-(1,4-benzodioxan-6-yl)-7-cinnamoyl-
oxychromones (III) and (IV). A mixture of cinnamic
acid (2.96 g, 20 mmol) and phosphorus pentachloride
(4.99 g, 240 mmol) was heated in dry toluene for
30 min, phosphorus oxychloride was distilled off, and a
solution of the corresponding 7-hydroxyisoflavone (I)
or (II) (10 mmol) in pyridine (20 ml) was added. The
reaction mixture was kept for 4 h at 100–110°C and
poured in 2% aqueous solution of hydrochloric acid
Thus, the easy obtaining of isoflavonoid acyl deriv-
atives at their hydroxyl groups allows the synthesis of
new interesting compounds.
1
Corresponding author: phone: 8-095-223-6439;
e-mail: katadjanov@mail.ru; compounds@intal.uz
402

A SYNTHESIS OF CINNABMOYLOXYISOFLAVONES
403
(200 ml). The precipitated crystals were filtered, dried, H2 + H3 + H4 + H5 + H6); protons of 1.4-benzodiox-
and recrystallized from DMF.
ane: 6.78 (1 H, d, J 2.0, H5), 6.72 (1 H, dd, J 7.5 and
2.0, H7), 6.93 (1 H, d, J 7.5, H8), 4.29 (4 H, s,
éëç2ëç2é. Found, %: C 74.05, H 4.8. ë28ç22é6.
Calc., %: C 74.02, H 4.84.
(III); yield 53%; mp 202–203°C; 1H NMR (DåSO-
d6, δ, ppm, J, Hz): chromanone protons: 2.30 (3 H, s, 2-
Me), 8.10 (1 H, d, J 8.5, H5), 7.35 (1 H, dd, J 8.5 and
2.5, H6), 7.60 (1 H, d, J 2.5, H8); cinnamoyl protons:
7.96 (1 H, d, J 15.5, α-ëç), 6.93 (1 H, d, J 15.5, β-ëç),
7.49–7.84 (5 H, m, H2 + H3 + H4 + H5 + H6); protons
of 1.4-benzodioxane: 6.80 (1 H, d, J 2.0, H5), 6.75 (1 H,
dd, J 7.5 and 2.0, H7), 6.94 (1 H, d, J 7.5, H8), 4.29
(4 H, s, éëç2ëç2é. Found, %: C 73.60, H 4.6.
ë27ç20é6. Calc., %: C 73.65, H 4.54.
REFERENCES
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18.0.39.P, 1988.
(IV); yield 60%; mp 182–183°C; 1H NMR (DåSO-
d6, δ, ppm, J, Hz): chromanone protons: 1.20 (3 H, t,
ëç3ëç2), 2.57 (2H, quintet, ëç3ëç2), 8.10 (1 H, d, J
8.5, H5), 7.34 (1 H, dd, J 8.5 and 2.5, H6), 7.63 (1 H, d,
J 2.5, H8); cinnamoyl protons: 7.95 (1 H, d, J 15.5, α-
ëç), 6.83 (1 H, d, J 15.5, β-ëç), 7.50–7.84 (5 H, m,
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RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY Vol. 32 No. 4 2006