Synthesis of sulfonamides and 1,3-Oxazine-2,4-diones from arylsulfonyl isocyanates and diketene

Article abstract of DOI:10.1055/s-2008-1067115

An effective route to functionalized N¹-[(2,6-dimethyl-4-oxo-4H- pyran-3-yl)carbony1]-l-arylsulfonamide and 3-(arylsul-fonyl)-6-methyl-2H-l,3- oxazine-2,4(3H)-dione derivatives is described. This involves the reaction of arylsulfonyl isocyanate

Full text of DOI:10.1055/s-2008-1067115

PAPER
2073
Synthesis of Sulfonamides and 1,3-Oxazine-2,4-diones from Arylsulfonyl
Isocyanates and Diketene
S
ynthesis of Sulfo
b
namides
a
nd
d
1,3-Oxazine
o
-2,4-dione
s
lali Alizadeh,* Nasrin Zohreh,a Long-Guan Zhub
a
Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran 18716, Iran
Chemistry Department, Zhejiang University, Hangzhou 310027, P. R. China
b
Fax +98(21)88006544; E-mail: abdol_alizad@yahoo.com; E-mail: aalizadeh@modares.ac.ir
Received 4 March 2008; revised 7 April 2008
O
O
Abstract: An effective route to functionalized N1-[(2,6-dimethyl-
4-oxo-4H-pyran-3-yl)carbonyl]-1-arylsulfonamide and 3-(arylsul-
fonyl)-6-methyl-2H-1,3-oxazine-2,4(3H)-dione derivatives is de-
scribed. This involves the reaction of arylsulfonyl isocyanates and
diketene in the presence of N-heteroaromatic compounds such as
1,3,5-triazine, 1-methyl-1H-imidazole, or pyridine as catalyst. The
reactive 1:1 zwitterions obtained from the addition of N-heteroaro-
matic compound to arylsulfonyl isocyanates were trapped by
diketene to produce functionalized sulfonamide and 1,3-oxazine-
2,4(3H)-dione derivatives.
H
H
OH
Me
S
O
O
N
H
O
2
3
Figure 2 Structure of maltol (2) and thiaisatoic anhydride (3)
Key words: arylsulfonyl isocyanate, catalytic reaction, diketene,
N-heteroaromatic compounds, sulfonamides, zwitterions
zyme systems and have potential as antibacterial, antican-
cer, and anti-allergic agents.11 Maltol (2) is a natural
compound, which is used widespread in food industry as
additive due to its flavor and antioxidant properties12 and
also in coordination chemistry (Figure 2).13
The importance of the sulfonamide unit in medicinal
chemistry cannot be overstated.1,2 They have been found
to possess a large number of different biological activities,
including antibacterial, antiviral, antidiabetic, diuretic,
and antithyroid activities.3–6 Recently, sulfonamides have
been found to be potent cysteine protease inhibitors,
which could possibly extend their therapeutic applications
to include conditions such as Alzheimer’s disease, arthri-
tis, and cancer.7 Using cell-based and microarray-based
screening strategies, sulfonamide-focused compound li-
braries have also been evaluated for their antitumor poten-
tial.8 Compound 1 is a precursor for the synthesis of
Celecoxib analgesic (Figure 1).9
Due to the broad spectrum of biological activities of 1,3-
oxazine-2,4-diones, including analgesic, antipyretic, bac-
teriostatic, fungistatic, and monoaminoxidase inhibitory
activity, they are an interesting class of compounds for
studying their chemistry.14 1H-Thieno[3,2-d][1,3]ox-
azine-2,4-dione (3, thiaisatoic anhydride) is a useful
building block for the synthesis of numerous heterocycles
with therapeutic interest (Figure 2).15
Although a variety of sulfonamide16 and pyrane17 synthe-
ses are known, despite the biological importance of them,
there currently exists no efficient procedure for preparing
compounds that have both N-acylsulfonamide and g-py-
rone units in their structure in one synthetic step. On the
other hand, surprisingly, only few synthetic methods for
1,3-oxazin-2,4-dione moiety have been reported in the lit-
erature so far. Most of them are multistep reactions using
expensive reagents and give low total yields18 and thus,
there is a clear need for generally useful, mild, and novel
method for their synthesis.
4H-Pyran-4-ones (g-pyrones) and their benzologues
(chromones and flavones), play different roles in plant
physiology and exhibit a diverse spectrum of biological
functions.10 They are interesting as pharmacological
agents since they stimulate or inhibit a wide variety of en-
Me
Therefore, to reach the mentioned purposes, we report
here the one-pot catalytic reaction between arylsulfonyl
isocyanates 4 and diketene in the presence of N-hetero-
aromatic compounds. The reaction between arylsulfonyl
isocyanate 4 and diketene in the presence of N-methylim-
idazole (NMI) or 1,3,5-triazine as N-heteroaromatic cata-
lyst proceeds in dichloromethane at ambient temperature
to produce exclusively N1-[(2,6-dimethyl-4-oxo-4H-pyr-
an-3-yl)carbonyl]-1-arylsulfonamides 5 in high yields.
But in the presence of pyridine, this reaction affords 3-(ar-
O
O
O
S
N
R
H
N
N
1
F3C
Figure 1 Precursor sulfonamide 1 for the synthesis of Celecoxib an-
algesic
SYNTHESIS 2008, No. 13, pp 2073–2076
Advanced online publication: 11.06.2008
x
x.
x
x
.
2
0
0
8
ylsulfonyl)-6-methyl-2H-1,3-oxazine-2,4(3H)-diones
6
DOI: 10.1055/s-2008-1067115; Art ID: Z05808SS
© Georg Thieme Verlag Stuttgart · New York

2074
A. Alizadeh et al.
PAPER
Table 1 Reaction of Arylsulfonyl Isocyanates 4 with Diketene
O
O
O
O
S
N
Ar
H
Me
Me
O
Me
O
O
O
5
CH2Cl2
S
+
+
NCO
2
O
Ar
catalyst, r.t.
O
O
O
4
S
O
N
Ar
O
Figure 3 X-ray crystal structure of 5a
6
Entry
4, Ar
Catalyst (20 mol%) Yield (%) Ratio of 5:6
NH at d = 13.06. The phenyl moiety gave rise to charac-
teristic signals in the aromatic region of the spectrum.
1
2
3
4
5
6
Tol
Ph
N-methylimidazole 85
N-methylimidazole 88
100:0
100:0
100:0
100:0
20:80
18:82
1
The H decoupled 13C NMR spectrum of 5a showed 13
distinct resonances in agreement with the sulfonamide
structure. Finally, the structure of 5a was further con-
firmed by a single crystal X-ray diffraction analysis
(Figure 3).
The 1H NMR spectrum of 6a exhibited three sharp singlet
signals due to the two methyl groups and a vinylic hydro-
gen (d = 2.15, 2.45 and 5.66, respectively). The 1H decou-
pled 13C NMR spectrum of 6a showed 10 distinct
resonances in agreement with the sulfonamide structure.
Tol
Ph
1,3,5-triazine
1,3,5-triazine
pyridine
90
90
80
83
Tol
Ph
pyridine
in addition to 5 as the main product with a ratio of 80:20
(Table 1).
Although the mechanism of the reaction between arylsul-
fonyl isocyanates 4 and diketene in the presence of N-het-
eroaromatic catalyst has not yet been established in an
experimental manner, a possible explanation for pyridine
catalyst that produces both 5 and 6 is proposed in
Scheme 1. Based on the well-established chemistry of iso-
cyanates with various nucleophiles,19–22 it is reasonable to
assume that 7 results from initial addition of pyridine (or
other catalysts) to arylsulfonyl isocyanates 4. Intermedi-
ate 7 is a stable zwitterion, but in the presence of diketene
The structures of compounds 5a,b and 6a,b were deduced
1
from their elemental analyses, IR, and high-field H and
13C NMR spectra. The IR spectrum of 5a showed absorp-
tion bands due to the two carbonyl groups at 1695 and
1652 cm–1 and a NH group at 3425 cm–1. The H NMR
1
spectrum of 5a exhibited five sharp singlet signals readily
recognized as arising from three methyl groups (d = 2.31,
2.42, and 2.72), vinylic hydrogen (d = 6.29) along with
O
O
O
O
O
O
O
py
SO2Ar
S
O
N
N
N
N
Ar
NCO
SO2Ar
7
8
4
O
O
O
O
O
O
Path A
6
Me
N
N
N
N
Me
– py
SO2Ar
SO2Ar
9
10
O
Path B
O
O
SO2Ar
O
O
O
H
N
N
O
O
ArO2S
O
N
5
O
O
– py
O
Me
Me
Me
11
12
Scheme 1
Synthesis 2008, No. 13, 2073–2076 © Thieme Stuttgart · New York

PAPER
Synthesis of Sulfonamides and 1,3-Oxazine-2,4-diones
2075
× 0.32 × 0.25 mm, MoKa radiation (l = 0.71073 Å), 2.73 £ 2q £
26.0, intensity data were collected at 295(2) K with a Bruker APEX
area-detector diffractometer employing w/2q scanning technique in
the range of –9 £ h £ 9, –10 £ k £ 5, –17 £ l £ 17. The structure was
solved by a direct method, all nonhydrogen atoms were positioned
and anisotropic thermal parameters refined from 2457 observed re-
flections with R (int) = 0.0119 by a full-matrix least-squares tech-
nique converged to R1 = 0.0476 and wR2 = 0.1467 [I > 2s(I)].
is converted into intermediate 8 which is in equilibrium
with 9 and 10.23–29 In path A, intermediate 10 cyclizes by
losing pyridine to give the corresponding 1,3-oxazine-
2,4(3H)-dione 6 derivatives. In path B, due to the result of
attack of intermediate 9 to a second molecule of diketene,
zwitterion 11 is formed, which loses pyridine to give pyr-
anooxazine tricarbonyl intermediate 12. Intermediate 12
is unstable and with loss of CO2 is converted into the cor-
responding N1-[(2,6-dimethyl-4-oxo-4H-pyran-3-yl)car-
bonyl]-1-arylsulfonamide derivatives 5.
N1-[(2,6-Dimethyl-4-oxo-4H-pyran-3-yl)carbonyl]-1-benzene-
sulfonamide (5b)
Colorless crystals; mp 135–137 °C.
In conclusion, the present method has the following ad-
vantages: (i) the reaction is performed under neutral con-
ditions and (ii) the substances can be mixed without any
activation or modification. The simplicity of the present
procedure makes it an interesting alternative to the com-
plex multistep approaches.
IR (KBr): 3410 (NH), 1696 (C=O), 1649 (NC=O), 1577 (C=C),
1537 and 1419 (Ar), 1346 and 1137 (SO2), 1170 and 1079 cm–1 (C–
O).
1H NMR (500.13 MHz, CDCl3): d = 2.32 (s, 3 H), 2.72 (s, 3 H), 6.30
(s, 1 H), 7.53 (t, J = 7.9 Hz, 2 H), 7.61 (t, J = 7.4 Hz, 1 H), 8.12 (d,
J = 7.6 Hz, 2 H), 13.07 (s, 1 H).
13C NMR (125.7 MHz, CDCl3): d = 19.52, 21.52, 114.69, 114.76,
128.40, 128.81, 133.51, 139.46, 161.72, 165.77, 176.54, 178.83.
GC-MS (EI 70 eV): m/z (%) = 308 (1, M+), 243 (9), 226 (21), 151
(22), 150 (100), 124 (11), 109 (17), 77 (22), 67 (19), 43 (17).
Arylsulfonyl isocyanates 4 and diketene were obtained from Merck
(Germany) and Fluka (Switzerland) and were used without further
purification. Melting points were measured on an Electrothermal
9100 apparatus. Elemental analyses for C, H and N were performed
using a Heraeus CHN–O–Rapid analyzer. Mass spectra were re-
corded on a Finnigan-Matt 8430 mass spectrometer operating at an
ionization potential of 20 eV. 1H and 13C NMR spectra were mea-
sured (CDCl3 solution) with a Bruker DRX-500 Avance spectrom-
eter at 500.1 and 125.8 MHz, respectively. IR spectra were recorded
on a Shimadzu IR-460 spectrometer. Chromatographic columns
were prepared from Merck silica gel (230–240 mesh).
Anal. Calcd for C14H13NO5S (307.32): C, 54.72; H, 4.26; N, 4.56.
Found: C, 54.30; H, 4.60; N, 4.70.
6-Methyl-3-[(4-methylphenyl)sulfonyl]-2H-1,3-oxazine-
2,4(3H)-dione (6a)
White powder; mp 140–142 °C.
IR (KBr): 1769 (OC=ON), 1717 (NC=O), 1670 (C=C), 1635 and
1586 (Ar), 1382 and 1191 (SO2), 1111 and 1077 cm–1 (C–O).
1H NMR (500.13 MHz, CDCl3): d = 2.15 (s, 3 H), 2.45 (s, 3 H), 5.66
(s, 1 H), 7.39 (d, J = 8.2 Hz, 2 H), 8.14 (d, J = 8.2 Hz, 2 H).
N1-[(2,6-Dimethyl-4-oxo-4H-pyran-3-yl)carbonyl]-4-methyl-1-
benzenesulfonamide (5a); Typical Procedure
To a magnetically stirred solution of p-toluenesulfonyl isocyanate
[4 (Ar = 4-MeC6H4); 0.2 g, 1 mmol] and the respective N-heterocy-
clic catalyst (20 mol%) in anhyd CH2Cl2 (5 mL) was added drop-
wise a solution of diketene (0.17 g, 2 mmol) in anhyd CH2Cl2 (3
mL) at 25 °C over 2 h. The mixture was stirred for 24 h. The solvent
was removed under reduced pressure, and the residue was separated
by silica gel column chromatography (hexane–EtOAc, 3:1). The
product was recrystallized in a mixture of toluene, n-hexane and
EtOAc. 5a was obtained as colorless crystals; mp 191–193 °C
(Table 1).
13C NMR (125.7 MHz, CDCl3): d = 19.03, 21.85, 101.92, 129.40,
129.81, 134.49, 144.39, 146.72, 158.42, 165.11.
GC-MS (EI 70 eV): m/z (%) = 217 (1), 197 (2), 155 (40), 133 (41),
91 (100), 65 (29), 43 (18).
Anal. Calcd for C12H11NO5S (281.28): C, 51.24; H, 3.94; N, 4.98.
Found: C, 51.36; H, 3.90; N, 4.90.
6-Methyl-3-(phenylsulfonyl)-2H-1,3-oxazine-2,4(3H)-dione
(6b)
White powder; mp 144–146 °C.
IR (KBr): 3425 (NH), 1695 (C=O), 1652 (NC=O), 1584 (C=C),
1538 and 1407 (Ar), 1343 and 1134 (SO2), 1163 and 1076 cm–1 (C–
O).
IR (KBr): 1763 (OC=ON), 1714 (NC=O), 1665 (C=C), 1617 and
1571 (Ar), 1380 and 1175 (SO2), 1117 and 1076 cm–1 (C–O).
1H NMR (500.13 MHz, CDCl3): d = 2.17 (s, 3 H), 5.71 (s, 1 H), 7.61
(t, J = 7.5 Hz, 2 H), 7.75 (t, J = 7.5 Hz, 1 H), 8.28 (d, J = 8.5 Hz, 2
1H NMR (500.13 MHz, CDCl3): d = 2.31 (s, CH3, 3 H), 2.42 (s,
CH3, 3 H), 2.72 (s, CH3, 3 H), 6.29 (s, C=CH, 1 H), 7.31 (d, J = 8.2
Hz, 2 Harom), 7.98 (d, J = 8.2 Hz, 2 Harom), 13.06 (s, NH, 1 H).
13C NMR (125.7 MHz, CDCl3): d = 19.51 (CH3), 21.48 (CH3),
21.65 (CH3 of Ar), 114.66 (C=CH), 114.79 (C-3 of pyran), 128.43
H).
13C NMR (125.7 MHz, CDCl3): d = 19.08, 101.89, 129.21, 129.31,
135.29, 137.34, 144.35, 158.35, 165.24.
GC-MS (EI 70 eV): m/z (%) = 267 (1, M+), 203 (1), 183 (1), 141
(28), 119 (32), 100 (5), 77 (100), 51 (34), 43 (29).
(2 CHarom), 129.43 (2 CHarom), 136.53 (Cipso-ArSO2), 144.51 (Cipso
-
ArMe), 161.72 (NCO), 165.80 (C-2 of pyran), 176.46 (C-6 of pyr-
an), 178.82 (C=O).
Anal. Calcd for C11H9NO5S (267.25): C, 49.44; H, 3.39; N, 5.24.
Found: C, 49.32; H, 3.45; N, 5.28.
MS: m/z (%) = 151 (23), 150 (70), 109 (28), 108 (46), 91 (50), 77
(18), 65 (38), 67 (50), 43 (100), 41 (30).
Anal. Calcd for C15H15NO5S (321.34): C, 56.07; H, 4.70; N, 4.36.
Found: C, 56.10; H, 4.80; N, 4.46.
References
Crystal Data30
(1) Navia, M. A. Science 2000, 288, 2132.
(2) Mohamed, S. K. Afinidad 2000, 57, 451; Chem. Abstr. 2000,
133, 73818x.
(3) Maren, T. H.; Conroy, C. W. J. Biol. Chem. 1993, 268,
26233.
C15H15NO5S; MW = 321.34, triclinic, space group P–1,
a = 7.3885(9) Å, b = 8.1143(10) Å, c = 14.1248(18) Å,
a = 76.866(1)°, b = 79.723(1)°, g = 69.187(1)°, V = 766.40(16) Å3,
Z = 2, Dcalcd = 1.392 mg/m3, F (000) = 336, crystal dimension 0.43
Synthesis 2008, No. 13, 2073–2076 © Thieme Stuttgart · New York

2076
A. Alizadeh et al.
PAPER
(4) Scozzafava, A.; Owa, T.; Mastrolorenzo, A.; Supuran, C. T.
Curr. Med. Chem. 2003, 10, 925.
(5) Owa, T.; Yoshino, H.; Okauchi, T.; Yoshimatsu, K.; Ozawa,
Y.; Sugi, N. H.; Nagasu, T.; Koyanagi, N.; Kitoh, K. J. Med.
Chem. 1999, 42, 3789.
(16) (a) Kawai, M.; BaMaung, N. Y.; Fidanze, S. D.; Erickson, S.
A.; Tedrow, J. S.; Sanders, W. J.; Vasudevan, A.; Park, C.;
Hutchins, C.; Comess, K. M.; Kalvin, D.; Wang, J.; Zhang,
Q.; Lou, P.; Tucker-Garcia, L.; Bouska, J.; Bell, R. L.;
Lesniewski, R.; Henkin, J.; Sheppard, G. S. Bioorg. Med.
Chem. Lett. 2006, 16, 3574. (b) Siddiqui, N.; Pandeya, S. N.
Bioorg. Med. Chem. Lett. 2007, 17, 255. (c) Johnson, D. C.;
Widlanski, T. S. Tetrahedron Lett. 2001, 42, 3677.
(d) Vogel, A. Textbook of Practical Organic Chemistry;
Longman: London, 1978, 4th ed., 647. (e) Cremlyn, R.
Organosulfur Chemistry: An Introduction; Wiley: New
York, 1996. (f) Anderson, K. K. Sulfonic Acids and Their
Derivatives, In Comprehensive Organic Chemistry, Vol. 3;
Barton, D. H. R.; Ollis, W. D.; Jones, D. N., Eds.; Pergamon
Press: Oxford, 1979. (g) Domínguez, J. N.; León, C.;
Rodrigues, J.; Domínguez, N.; Gut, J.; Rosenthal, P.
Farmaco 2005, 60, 307. (h) Murakami, Y.; Kondo, K.;
Sekimoto, E.; Nakao, J. Tetrahedron 2000, 56, 5843. (i)Ito,
Y.; Manabe, S.; Sugioka, T. Tetrahedron Lett. 2007, 48,
787. (j) Alizadeh, A.; Rostamnia, S.; Esmaili, A. Synthesis
2007, 709.
(17) (a) Bartol, G.; Bosco, M.; Cimarreli, C.; Dalpozo, R.;
Guereio, G.; Palmieri, G. J. Chem. Soc., Perkin Trans. 1
1993, 2081. (b) Yamamoto, Y.; Morita, Y. Chem. Pharm.
Bull. 1984, 32, 2957. (c) Majetich, G.; Zhanj, Y.; Dreger, G.
Tetrahedron Lett. 1993, 34, 449. (d) Ficini, J.; Pouliquen, J.
Tetrahedron Lett. 1972, 1135. (e) Sano, T.; Saitoh, T.
Heterocycles 1993, 36, 2139. (f) Kim, H. S.; Yoon, Y. H.
Bull. Korean Chem. Soc. 1993, 14, 159. (g) Andrey Chicov,
Y. S.; Vinokurova, O. V.; Gein, V. L. Chem. Heterocycl.
Compd. (English Trans.) 1989, 126. (h) Weeks, P. D.;
Brennan, T. M.; Brannegan, T. D.; Kuhla, D. E.; Elliott, M.
L.; Watson, H. A. J. Org. Chem. 1980, 45, 1109. (i) Grrige,
R.; Jachson, G. L. J. Chem. Soc. C 1970, 552. (j) Harris, T.
M.; Wachter, M. P. Tetrahedron 1970, 26, 5255.
(18) (a) Clauson-Kaas, N.; Denss, R.; Ostermayer, F.; Renk, E. J.
R. Geigy A.G., Swiss Appl. 436323, 1968; Chem. Abstr.
1968, 69, 27435g. (b) Clauson-Kaas, N.; Denss, R.;
Ostermayer, F.; Renk, E. J. R. Geigy A.G., Swiss Appl. 412
602, 1967; Chem. Abstr. 1967, 67: 11492w.
(6) Koyanagi, N.; Nagasu, T.; Fujita, F.; Watanabe, T.;
Tsukahara, K.; Funahashi, Y.; Fujita, M.; Taguchi, T.;
Yoshino, H.; Kitoh, K. Cancer Res. 1994, 54, 1702.
(7) (a) Roush, W. R.; Gwaltney, S. L.; Cheng, J.; Scheidt, K. A.;
McKerrow, J. H.; Hansell, E. J. Am. Chem. Soc. 1998, 120,
10994. (b) Roush, W. R.; Cheng, J.; Knapp-Reed, B.;
Alvarez-Hernandez, A.; McKerrow, J. H.; Hansell, E.;
Engel, J. C. Bioorg. Med. Chem. Lett. 2001, 11, 2759.
(c) Maren, T. H. Annu. Rev. Pharmacol. Toxicol. 1976, 16,
309. (d) Supuran, C. T.; Briganti, F.; Tilli, S.; Chegwidden,
W. R.; Scozzafava, A. Bioorg. Med. Chem. 2001, 9, 703.
(e) Scozzafava, A.; Menabuoni, L.; Mincione, F.; Briganti,
F.; Mincione, G.; Supuran, C. T. J. Med. Chem. 2000, 43,
4542.
(8) (a) Yokoi, A.; Kuromitsu, J.; Kawai, T.; Nagasu, T.; Sugi, N.
H.; Yoshimatsu, K.; Yoshino, H.; Owa, T. Mol. Cancer
Ther. 2002, 1, 275. (b) Oda, Y.; Owa, T.; Sato, T.; Boucher,
B.; Daniels, S.; Yamanaka, H.; Shinohara, Y.; Yokoi, A.;
Kuromitsu, J.; Nagasu, T. Anal. Chem. 2003, 75, 2159.
(c) Owa, T.; Yokoi, A.; Yamazaki, K.; Yoshimatsu, K.;
Yamori, T.; Nagasu, T. J. Med. Chem. 2002, 45, 4913.
(d) Owa, T.; Okauchi, T.; Yoshimatsu, K.; Sugi, N. H.;
Ozawa, Y.; Nagasu, T.; Koyanagi, N.; Okabe, T.; Kitoh, K.;
Yoshino, H. Bioorg. Med. Chem. Lett. 2000, 10, 1223.
(9) Huang, S.; Connolly, P. J.; Lin, R.; Emanuel, S.; Middleton,
S. A. Bioorg. Med. Chem. Lett. 2006, 16, 3639.
(10) (a) Staunton, J. In Comprehensive Organic Chemistry, Vol.
4; Barton, D. H. R.; Ollis, W. D., Eds.; Pergamon Press:
Oxford, 1979, 679. (b) See also: Staunton, J. In
Comprehensive Organic Chemistry, Vol. 4; Barton, D. H.
R.; Ollis, W. D., Eds.; Pergamon Press: Oxford, 1979, 688.
(11) (a) See also: Ellis, G. P. In The Chemistry of Heterocyclic
Compounds Chromenes, Chromanones and Chromones,
Vol. 31; Weissberger, A.; Taylor, E. C., Eds.; Wiley: New
York, 1977, 912. (b) Ellis, G. P. In The Chemistry of
Heterocyclic Compounds Chromenes, Chromanones and
Chromones, Vol. 31; Weissberger, A.; Taylor, E. C., Eds.;
Wiley: New York, 1977, 985. (c) Ellis, G. P. In The
Chemistry of Heterocyclic Compounds Chromenes,
Chromanones and Chromones, Vol. 31; Weissberger, A.;
Taylor, E. C., Eds.; Wiley: New York, 1977, 1063.
(12) (a) Kato, Y. Food Sci. Technol. Res. 2003, 9, 264.
(b) Yanagimoto, K.; Ochi, H.; Lee, K. G.; Shibamoto, T.
J. Agric. Food Chem. 2004, 52, 592.
(13) (a) Caravan, P.; Gelmini, L.; Glover, N.; Herring, F. G.;
McNeill, H.; Li, J. H.; Rettig, S. J.; Setyawati, I. A.; Shuter,
E.; Sun, Y.; Tracey, A. S.; Yuen, V. G.; Orvig, C. J. Am.
Chem. Soc. 1995, 117, 12759. (b) Reffitt, D. M.; Burden, T.
J.; Seed, P. T.; Wood, J.; Thompson, R. P. H.; Powell, J. J.
Ann. Clin. Biochem. 2000, 37, 457. (c) Johnson, V. J.;
Sharma, R. P. Neurotoxicology 2003, 24, 261. (d) Hinds, F.
E.; Aldrich-Wright, J. R.; Leverett, P.; Hazell, S. L. J. Inorg.
Biochem. 2003, 96, 144. (e) Ellis, B. L.; Duhme, A. K.;
Hider, R. C.; Hossian, M. B.; Rizvi, S.; van der Helm, D.
J. Med. Chem. 1996, 39, 3659.
(19) Huisgen, R.; Herbig, K.; Morikawa, M. Chem. Ber. 1967,
100, 1107.
(20) Ulrich, H. Chem. Rev. 1962, 2, 186.
(21) Adib, M.; Yavari, H.; Mollahosseini, M. Tetrahedron Lett.
2004, 45, 1803.
(22) Ozaki, S. h. Chem. Rev. 1972, 72, 457.
(23) Alizadeh, A.; Zohreh, N.; Rostamnia, S. Tetrahedron 2007,
63, 8083.
(24) Mansson, M.; Nakase, Y.; Sunner, S. Acta Chem. Scand.
1968, 22, 171.
(25) Briody, J. M.; Satchell, D. P. N. J. Chem. Soc. 1965, 3778.
(26) Briody, J. M.; Satchell, D. P. N. Chem. Ind. (London) 1964,
893.
(27) Eck, H. Wacker Chemie GmbH, Br. Patent 1346701, 1974;
Chem. Abstr. 1973, 79, 18109.
(28) Marcus, E.; Chan, J. K.; Strow, C. B. J. Org. Chem. 1966,
31, 1369.
(29) (a) Pochan, M. Lonza Ltd., Swiss Patent 523223, 1972;
Chem. Abstr. 1972, 77, 100857. (b) Stocker, A. Lonza, US
Patent 3778474, 1973; Chem. Abstr. 1974, 80, 59503.
(c) Kunstle, G.; Spes, H.; Siegl, H. Wacker-Chemie GmbH,
U.S. Patent 4129596, 1978; Chem. Abstr. 1978, 89, 42479f.
(30) Crystallographic data for 5a have been deposited with the
Cambridge Crystallographic Data Centre as supplementary
publication number CCDC 642465. Copies of the data may
be obtained, free of charge, on application to CCDC, 12
Union Road, Cambridge, CB2 1EZ, UK (fax: +44 1223
33603 or e-mail: deposit@ccdc.cam.ac.uk).
(14) (a) Clauson-Kaas, N.; Denss, R.; Ostermayer, F.; Renk, E. J.
R. Geigy A.G., Swiss Appl. 1339175, 1961; Chem. Abstr.
1964, 60, 4158d. (b) Clauson-Kaas, N.; Denss, R.;
Ostermayer, F.; Renk, E. J. R. Geigy A.G. Swiss Appl.
419160, 1967; Chem. Abstr. 1967, 66, 115718v.
(15) (a) Coppola, G. M. Synthesis 1980, 503. (b) Coppola, G.
M.; Marsden, C. M. Heterocycl. Commun. 1996, 2, 301.
Synthesis 2008, No. 13, 2073–2076 © Thieme Stuttgart · New York