330
You et al.
1H-NMR (300 MHz, CDCl3): δ 3.76 (3H, s), 3.85 (3H, s), 6.48 (1H, s), 6.77 (1H,
s), 7.57–7.60 (3H, m), 8.01–8.05 (m, 2H). 13C-NMR (75MHz, DMSO-d6): δ55.7, 60.9,
96.9, 106.2, 107.8, 125.7, 128.8, 129.1, 131.1, 131.3, 151.5, 155.4, 155.7, 159.0, 175.7. IR
(KBr): 3123, 1635, 1579, 1501, 1397, 1339, 1207, 1114 cm−1. EI-MS (m/z): 298 (M+),
283, 255, 153.
Wogonin (5,7-Dihydroxy-8-methoxyflavone, 5)
A solution of 9 (5.0 g, 17 mmol) in acetonitrile (250 mL) was added anhydrous AlCl3
(11.0 g, 17 mmol) at 0◦C under a nitrogen atmosphere. The reaction mixture was heated at
reflux for 4 h and then poured into 200 mL of 3N HCl. Extraction with ethyl acetate (200
mL), drying over anhydrous Na2SO4 followed by evaporation of the solvent gave the crude
product which was recrystallized from ethanol to give a yellow solid (15.0 g, 84%), mp
201–202◦C, lit.7198–199◦C.
1H-NMR (300MHz, DMSO-d6): δ 3.86 (3H, d, J = 1.8 Hz), 6.32 (1H, s), 7.01 (1H, s),
7.61–7.64 (3H, m), 8.07–8.09 (2H, m), 10.82 (1H, s), 12.51 (1H, d, J = 1.8 Hz). 13C-NMR
(75MHz, DMSO-d6): δ 61.0, 99.1, 103.7, 105.3, 126.2, 127.8, 129.2, 130.8, 132.0, 149.6,
156.2, 157.3, 163.0, 182.0. IR (KBr) : 3411, 1660, 1579 cm−1. EI-MS (m/z): 284 (M+).
Acknowledgements
The authors gratefully acknowledge financial support from the National Natural Science
Foundations of China (Grant No. 30701032 and 90713038).
References
1. C. K. Han, M. J. Son, H. W. Chang, Y. S. Chi, H. Park and H. P. Kim, Biol. Pharm. Bull., 28,
1366 (2005).
2. M. C. Tai, S. Y. Tsang, L. Y. F. Chang and H. Xue, CNS Drug Reviews, 11, 141 (2005).
3. S. C. Fas, S. Baumann, J. Y. Zhu, M. Giaisi, M. K. Treiber, U. Mahlknecht, P. H. Krammer and
M. L. Weber, Blood, 108, 3700 (2006).
4. Q. L. Guo, L. Zhao, Q. D. You, Y. Yang, H. Y. Gu, G. L. Song, N. Lu, and J. Xin, Antiviral Res.,
74, 16 (2007).
5. J. Allan and R. Robinson, J. Chem. Soc., 12s, 2192 (1924).
6. P. K. Venkatswara, R. K. Visweswara and R. Seshadri, Proc. Indian Acad. Sci., 26A, 13 (1943).
7. H. S. Mahal and K. Venkataraman, Curr. Sci., 2, 214 (1933).
8. A. Hercouet, M. LeCorre and Y. LeFloc’h, Synthesis, 597 (1982).
9. W. H. Huang, P. Y. Chien and C. H. Yang, Chem. Pharm. Bull., 51, 339 (2003), Chem. Abstr.,
139, 149434r, (2003).
10. T. A. Geissman and T. G. Halsall, J. Am.Chem. Soc., 73, 1280 (1951).
11. D. C. G. A. Pinto, A. M. S. Silva and J. A. S. Cavaleiro, J. Heterocyclic. Chem., 33, 1887 (1996).
12. R. C. Shah, C. R. Mehta and T. S. Wheeler, J. Chem. Soc., 1555 (1938).
13. P. Rivaille and C. Mentzer, C. R Acad. Sc. Paris, Se´rie C, 268, 2213 (1969), Chem. Abstr., 71,
61142k, (1969).
14. A. Maradufu and J. H. Ouma, Phytochemistry, 17, 823 (1978).