NMR of a series of novel hydroxyflavothiones
5-hydroxyflavothione 2b
using dichloromethane-ethyl acetate (10 : 1 v/v) as eluent gave
compound 7b as yellow crystals, yield 49%, mp 168–169 ◦C APCI-
MS, 373 (M-1). IR KBr (γ , cm−1), 2934 (w), 1646 (s), 1584 (s), 1499
(s), 1448 (s), 1346 (w), 1318 (s), 1275 (s), 1247 (s), 1221 (s), 1159 (s),
1021 (s), 876 (w), 772 (m), 667 (w). For 1H and 13C NMR data, see
Tables 2c and 3c.
The synthesis was carried out analogously to 1b using a mixture
of primuletin (2) (238 mg, 1.0 mmol) and Lawesson’s reagent
(202 mg, 0.5 mmol), and gave after column chromatography on
silica gel, using hexane-ethyl acetate (9 : 1 v/v) as eluent, and
recrystallization from methanol–hexane (1 : 1 v/v) compound 2b
as a yellow crystal, yield 90%, mp 136–137 ◦C, APCI-MS, 253 (M-1).
IR, KBr (γ , cm−1), 3057 (vw), 1630 (s), 1598 (s), 1575 (m), 1497 (w),
1460 (s), 1343 (w), 1306 (vw), 1249 (m), 1166 (w), 1028 (w), 874 (w),
769 (m), 683 (m). For 1H and 13C NMR data, see Tables 2a and 3a.
7-Butyloxy-4ꢀ,5-dihydroxyflavothione9band7-butyloxy-4ꢀ,5-
dihydroxyflavanonethion 9c
The synthesis was carried out analogously to 1b using a mixture
of compound 9a (328 mg, 1.0 mmol) and Lawesson’s reagent
(202 mg, 0.5 mmol). Column chromatography on silica gel using
dichloromethane as eluent the early fractions gave compound 9b
5,7-dihydroxyflavothione 3b
◦
The synthesis was carried out analogously to 1b using a
mixture of chrysin (3) (254 mg, 1.0 mmol) and Lawesson’s reagent
(202 mg, 0.5 mmol). After column chromatography on silica gel,
using dichloromethane-ethyl acetate (10 : 1 v/v) as eluent gave
compound 3b as yellow crystals, yield 8%, mp 218 ◦C, APCI-MS,
269 (M-1). IR KBr (γ , cm−1), ∼3400 (vw, br), 3057 (vw), 1630 (s),
1598 (s), 1575 (m), 1497 (w), 1460 (s), 1343 (w), 1306 (vw), 1249
as yellow crystals, yield 15%, mp 144–145 C, APCI-MS, 340 (M-1).
IR KBr (γ , cm−1), 3446 (br,s), 2959, 2930, 2873 (w), 1639 (s), 1579
(m), 1501 (m),1464 (m), 1379 (m), 1288 (m), 1271 (w), 1203 (w) 1174
(m), 1124 (m), 1074 (m), 836 (m), 743 (w), 700(w). The later fractions
gave product 9c as yellow crystals, yield 26%, mp 128–129 ◦C,
APCI-MS, 342 (M-1). IR KBr (γ , cm−1), 3423 (br,s), 2955, 2931, 2875
(w), 1627 (s), 1556 (m), 1455 (m), 1349 (m), 1286 (m), 1256(w), 1204
(m), 1166 (w), 1028 (w), 874 (w), 769 (m), 683 (m). For 1H and 13
NMR data, see Tables 2a and 3a.
C
(m) 1166 (m), 1117 (m), 1061(m), 831(m), 700(w). For 1H and 13
NMR data, see Tables 2c and 3b.
C
10b and c were synthesized as described above using
7-Dodecyloxy-5-hydroxyflavothione 4b
decylbromide. None of the products were fully purified.
The synthesis was carried out analogously to 1b using a
mixture of 4a (422 mg, 1.0 mmol) and Lawesson’s reagent
(202 mg, 0.5 mmol). Column chromatography on silica gel, using
dichloromethane as eluent gave compound 4b as yellow crystals,
yield 52%, mp 104–105 ◦C, APCI-MS, 438 (M-1)+. IR KBr (γ , cm−1),
2922 (s), 1645 (m), 1598 (m), 1574 (w), 1492 (vw), 1467 (w), 1380
(w), 1303 (w), 1262 (vw), 1178 (w), 1028 (w), 874 (w), 769 (m), 683
(m). For 1H and 13C NMR data, see Tables 2b and 3a.
4ꢀ-Methoxy-5,7-dihydroxyisoflavothione 11b
The synthesis was carried out analogously to 1b using a mixture
of biochanin A (11a) (284 mg, 1.0 mmol) and Lawesson’s reagent
(202 mg, 0.5 mmol). Column chromatography on silica gel, using
dichloromethaneaseluentgavecompound11basyellowcrystals,
yield 29%, mp 162–163 ◦C, APCI-MS, 300 (M-1). IR KBr (γ , cm−1),
∼3450 (w, br), 2929 (w), 1611 (s), 1594 (s), 1509 (s), 1459 (w), 1409
(w), 1295 (m), 1252 (s), 1179 (m), 1025 (m), 890 (w), 803 (w), 707
(w). For 1H and 13C NMR data, see Tables 2a and 3b.
7-Butyloxy-5-hydroxyflavothione 5b
The synthesis was carried out analogously to 1b using a
mixture of 5a (310 mg, 1.0 mmol) and Lawesson’s reagent
(202 mg, 0.5 mmol). Column chromatography on silica gel, using
dichloromethane as elue◦nt gave compound 5b as yellow crystals,
Acknowledgements
The authors express thanks to Rita Buch and Annette Christensen
for their invaluable help in running NMR spectra and Eva Marie
Karlsen for her excellent work in recording IR spectra. The
financialsupportfromDANIDAthroughanENRECAgrantisgreatly
appreciated.
yield 82%, mp 121–122 C, APCI-MS, 325 (M-1). IR KBr (γ , cm−1
)
2954 (s), 1648 (s), 1599 (s), 1575 (m), 1492 (w), 1450 (w), 1382 (m),
1305 (s), 1265 (m), 1177 (s), 1032 (w), 873 (vw), 767 (m), 681 (w).
For 1H and 13C NMR data, see Tables 2b and 3b.
2ꢀ,3,4ꢀ,7-Tetramethoxy-5-hydroxyflavothione 6b
References
The synthesis was carried out analogously to 1b using a
mixture of 6a (358 mg, 1.0 mmol) and Lawesson’s reagent
(202 mg, 0.5 mmol). Column chromatography on silica gel,
using dichloromethane–ethyl acetate (10 : 1 v/v) as eluent gave
compound 6b as yellow crystals, yield 48%, mp 157–158 ◦C, APCI-
MS, 373 (M-1). IR KBr (γ , cm−1), 2925 (m), 1646 (s), 1584 (s), 1497
(m), 1456 (s), 1339 (w), 1306 (w), 1282 (m), 1221 (m), 1162 (s), 1024
(m), 837 (m), 790 (w), 670 (vw). For 1H and 13C NMR data, see
Tables 2c and 3c.
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Magn. Reson. Chem. 2009, 47, 1043–1054
Copyright ꢀ 2009 John Wiley & Sons, Ltd.