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0°C. After the addition was completed, the reaction mixture Compound 8i was synthesized as similar procedure described
was allowed to warm to room temperature and was stirred for for 8f from 7 using n-pentanol in place of isopropanol: Yield
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1h. The solution was concentrated in vacuo and THF (5mL) 63.3%, mp 178–179°C. H-NMR (400MHz, DMSO-d6) δ: 0.89
was added to the residue, then concentrated hydrochloric (3H, t, J=7.6Hz), 1.34–1.36 (4H, m), 1.61 (2H, m), 3.74 (3H,
acid (5mL) was added to the reaction mixture and stirred for s), 3.83 (3H, s), 4.09 (2H, t, J=7.2Hz), 6.61–6.74 (3H, m), 7.20
30min. The reaction solution was concentrated in vacuo and (1H, d, J=8.4Hz), 9.33 (1H, s). ESI-MS m/z: 445.11 [M+Na]+.
water (30mL) was added, the aqueous phase was extracted Anal. Calcd. for C19H22N2O5S2: C, 54.01; H, 5.25; N, 6.63; O,
with CH2Cl2 (3×15mL). The combined organic layer was 18.93; S, 15.18. Found: C, 54.10; H, 5.26; N, 6.58; O, 18.99; S,
washed with brine and dried over MgSO4, filtered, evaporated, 15.07.
and purified by flash column chromatography to get com-
[4-(2,4-Dimethoxyphenyl)-5-oxo-4,5-dihydro[1,2]dithi-
pound 8e (337mg, 83%) as pale yellow solid. mp 245-248°C. olo[4,3-b]pyrrol-6-yl]carbamic Acid Cyclopentyl Ester (8j)
1H-NMR (400MHz, DMSO-d6) δ: 3.73 (3H, s), 3.82 (3H, Compound 8j was synthesized as similar procedure described
s), 6.24 (1H, s), 6.60–6.73 (3H, m), 7.19 (1H, d, J=8.4Hz), for 8f from 7 using cyclopentanol in place of isopropanol:
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8.31 (1H, s). ESI-MS m/z: 374.05 [M+Na]+. Anal. Calcd for Yield 67.5%, mp 228–230°C. H-NMR (400MHz, DMSO-d6)
C14H12N2O5S2: C, 47.72; H, 3.43; N, 7.95; O, 22.70; S, 18.20. δ: 1.56–1.69 (6H, m), 1.84–1.86 (2H, m), 3.72 (3H, s), 3.82
Found: C, 47.65; H, 3.40; N, 7.99; O, 22.64; S, 18.32.
(3H, s), 5.07–5.08 (1H, m), 6.61–6.74 (3H, m), 7.19 (1H, d,
[4-(2,4-Dimethoxyphenyl)-5-oxo-4,5-dihydro[1,2]dithi- J=8.8Hz), 9.16 (1H, s). ESI-MS m/z: 443.11 [M+Na]+. Anal.
olo[4,3-b]pyrrol-6-yl]carbamic Acid Isopropyl Ester (8f) Calcd for C19H20N2O5S2: C, 54.27; H, 4.79; N, 6.66; O, 19.02;
The solution of isopropanol (36mg, 0.6mmol) and triethyl- S, 15.25. Found: C, 54.33; H, 4.82; N, 6.71; O, 18.95; S, 15.19.
amine (61mg, 0.6mmol) in THF (20mL) was stirred and al-
[4-(2,4-Dimethoxyphenyl)-5-oxo-4,5-dihydro[1,2]dithi-
lowed to cool to 0°C, followed by the dropwise addition of olo[4,3-b]pyrrol-6-yl]carbamic Acid Heptyl Ester (8k)
a solution of compound of triphosgene (180mg, 0.6mmol) in Compound 8k was synthesized as similar procedure described
THF (5mL). The reaction mixture was allowed to warm to for 8f from 7 using n-heptanol in place of isopropanol: Yield
room temperature and was stirred for 30min. The reaction 81.5%, mp 144–146°C. 1H-NMR (400MHz, DMSO-d6) δ:
mixture was added the compound 7 (300mg, 0.9mmol) and 0.89 (3H, t, J=6.6Hz), 1.3–1.34 (8H, m), 1.65–1.68 (2H, m),
was stirred at room temperature for 2h. The reaction solution 3.75 (3H, s), 3.83 (3H, s), 4.17 (2H, t, J=6.4Hz), 6.27 (1H, s),
was concentrated in vacuo and water (30mL) was added, the 6.53–6.57 (2H, m), 6.88 (1H, s), 7.17 (1H, d, J=8.8Hz). ESI-
aqueous phase was extracted with CH2Cl2 (3×15mL). The MS m/z: 473.18 [M+Na]+. Anal. Calcd for C21H26N2O5S2: C,
combined organic layer was washed with brine and dried over 55.98; H, 5.82; N, 6.22; O, 17.75; S, 14.23. Found: C, 55.89; H,
anhydrous MgSO4, filtered, evaporated, and purified by col- 5.86; N, 6.19; O, 17.79; S, 14.27.
umn chromatography to get title compound 8f (283mg, 80%)
[4-(2,4-Dimethoxyphenyl)-5-oxo-4,5-dihydro[1,2]dithi-
as pale yellow solid, mp 230–232°C. 1H-NMR (400MHz, olo[4,3-b]pyrrol-6-yl]carbamic Acid 2-Phenylethyl Ester
DMSO-d6) δ: 1.25 (6H, d, J=6.0Hz), 3.73 (3H, s), 3.82 (3H, s), (8l) Compound 8l was synthesized as similar procedure
4.88–4.91 (1H, m), 6.61–6.64 (1H, m), 6.74–6.75 (2H, m), 7.19 described for 8f from 7 using 2-phenylethanol in place of iso-
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(1H, d, J=8.8Hz), 9.17 (1H, brs). ESI-MS m/z: 417.09 [M+ propanol: Yield 68.5%, mp 200–203°C. H-NMR (400MHz,
Na]+. Anal. Calcd for C17H18N2O5S2: C, 51.76; H, 4.60; N, 7.10; DMSO-d6) δ: 2.94 (2H, t, J=6.8Hz), 3.73 (3H, s), 3.83 (3H, s),
O, 20.28; S, 16.26. Found: C, 51.89; H, 4.55; N, 7.17; O, 20.19; 4.30 (2H, t, J=6.8Hz), 6.61–6.63 (1H, m), 6.73–6.76 (2H, m),
S, 16.20.
7.18–7.31 (5H, m), 9.41 (1H, brs). ESI-MS m/z: 479.07 [M+
[4-(2,4-Dimethoxyphenyl)-5-oxo-4,5-dihydro[1,2]dithi- Na]+. Anal. Calcd for C22H20N2O5S2: C, 57.88; H, 4.42; N, 6.14;
olo[4,3-b]pyrrol-6-yl]carbamic Acid n-Butyl Ester (8g) O, 17.52; S, 14.05. Found: C, 57.95; H, 4.47; N, 6.08; O, 17.46;
Compound 8g was synthesized as similar procedure described S, 14.04.
for 8f from 7 using n-butyl alcohol in place of isopropanol:
[4-(2,4-Dimethoxyphenyl)-5-oxo-4,5-dihydro[1,2]dithi-
Yield 75%, mp 177–178°C. 1H-NMR (400MHz, DMSO-d6) olo[4,3-b]pyrrol-6-yl]carbamic Acid 4-Methoxyphenyl Ester
δ: 0.91 (3H, t, J=7.2Hz), 1.35–1.40 (2H, m), 1.56–1.63 (2H, (8m) Compound 8m was synthesized as similar proce-
m), 3.73 (3H, s), 3.82 (3H, s), 4.11 (2H, t, J=6.4Hz), 6.60–6.75 dure described for 8f from 7 using p-methoxyphenol in
(3H, m), 7.19 (1H, d, J=8.8Hz), 9.31 (1H, brs). ESI-MS m/z: place of isopropanol: Yield 65%, mp 204–206°C. 1H-NMR
431.09 [M+Na]+. Anal. Calcd for C18H20N2O5S2: C, 52.92; H, (400MHz, DMSO-d6) δ: 3.73 (3H, s), 3.74 (3H, s), 3.83 (3H, s),
4.93; N, 6.86; O,19.58; S, 15.70. Found: 52.84; H, 4.97; N, 6.90; 6.62–6.64 (1H, m), 6.75–6.76 (1H, m), 6.82 (1H, s), 6.96 (2H,
O, 19.51; S, 15.78.
d, J=9.2Hz), 7.12 (2H, d, J=8.8Hz), 7.21 (1H, d, J=9.2Hz),
[4-(2,4-Dimethoxyphenyl)-5-oxo-4,5-dihydro[1,2]dithi- 9.99 (1H, brs). ESI-MS m/z: 481.02 [M+Na]+. Anal. Calcd for
olo[4,3-b]pyrrol-6-yl]carbamic Acid Isobutyl Ester (8h) C21H18N2O6S2: C, 55.01; H, 3.96; N, 6.11; O, 20.94; S, 13.99.
Compound 8h was synthesized as similar procedure described Found: C, 55.12; H, 3.99; N, 6.03; O, 20.88 S, 13.98.
for 8f from 7 using isobutyl alcohol in place of isopropanol:
[4-(2,4-Dimethoxyphenyl)-5-oxo-4,5-dihydro[1,2]dithi-
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Yield 68%, mp 226–227°C. H-NMR (400MHz, DMSO-d6) olo[4,3-b]pyrrol-6-yl]carbamic Acid 4-Chlorophenyl Ester
δ: 0.92 (6H, d, J=7.2Hz), 1.91 (1H, m), 3.74 (3H, s), 3.82 (3H, (8n) Compound 8n was synthesized as similar procedure
s), 3.89 (2H, d), 6.60–6.75 (3H, m), 7.19 (1H, d, J=8.8Hz), described for 8f from 7 using p-chlorophenol in place of
9.35 (1H, s). ESI-MS m/z: 431.09 [M+Na]+. Anal. Calcd for isopropanol: Yield 70%, mp 234–236°C. H-NMR (400MHz,
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C18H20N2O5S2: C, 52.92; H, 4.93; N, 6.86; O, 19.58; S, 15.70. DMSO-d6) δ: 3.75 (3H, s), 3.84 (3H, s), 6.48–6.70 (5H, m), 7.19
Found: C, 52.99; H, 4.89; N, 6.91; O, 19.48; S, 15.73.
(1H, d, J=8.8Hz), 7.66 (1H, s), 9.53 (1H, brs). ESI-MS m/z:
[4-(2,4-Dimethoxyphenyl)-5-oxo-4,5-dihydro[1,2]dithi- 485.03 [M+Na]+. Anal. Calcd for C20H15ClN2O5S2: C, 51.89; H,
olo[4,3-b]pyrrol-6-yl]carbamic Acid n-Pentyl Ester (8i) 3.27; Cl, 7.66; N, 6.05; O, 17.28; S, 13.85 . Found: C, 51.84; H,