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H. Henon et al. / Bioorg. Med. Chem. 14 (2006) 3825–3834
3832
dioxane (5 mL). The mixture was stirred at room tem-
perature for 3 h. After filtration, the filtrate was evapo-
rated and the residue was purified by flash
chromatography (eluent: cyclohexane/EtOAc 7:3) to
give compound 16 (197 mg, 0.55 mmol, 86% yield) as a
(2H, s), 7.27–7.42 (5H, m), 7.56 (1H, dd, J1 = 8.5 Hz,
J2 = 1.0 Hz), 7.70 (1H, d, J = 8.5 Hz), 8.86 (1H, s),
11.56 (1H, s, NH), 11.59 (1H, s, NH), 12.68 (1H, s, NH).
13C NMR (100 MHz, DMSO-d6): 31.5, 31.9, 68.8, 71.9
(CH2), 112.7, 124.6, 127.3, 127.5 (2C), 128.2 (2C),
130.9 (C tert arom), 117.8, 119.3, 119.5, 124.2, 125.5,
131.4, 135.0, 137.0, 138.6, 142.6 (C quat arom), 166.4,
166.5, 168.7, 169.3 (C@O).
yellow solid. Mp 160 °C. IR (KBr) mC@C = 1610 cmÀ1
,
mC@O 1705, 1760 cmÀ1, mNH 3150–3400 cmÀ1. Mass
(ESI+) 383 [M+Na]+.
1H NMR (400 MHz, DMSO-d6): 1.91–2.00 (2H, m),
2.82 (2H, t, J = 7.5 Hz), 3.49 (2H, t, J = 6.5 Hz), 4.50
(2H, s), 6.84 (1H, d, J = 1.0 Hz), 7.13 (1H, dd,
J1 = 8.5 Hz, J2 = 1.5 Hz), 7.28–7.41 (5H, m), 7.45 (1H,
d, J = 8.5 Hz), 7.81 (1H, s), 8.35 (1H, d, J = 3.0 Hz),
10.77 (1H, s, NH), 11.96 (1H, d, J = 2.5 Hz, NH).
6.1.17.
(E)-10-Styryl-1,3,4,6-tetrahydro-2H,5H,7H-
dipyrrolo[3,4-a:3,4-c]carbazole-1,3,4,6-tetraone (22). A
mixture of 17 (107 mg, 0.338 mmol) and maleimide
(36 mg, 0.371 mmol) in p-xylene (5.8 mL) was refluxed
for 24 h. After cooling, the mixture was filtered off,
and the solid residue was washed with p-xylene and then
was dried to give 124.6 mg of intermediate 20. Com-
pound 20 (123 mg) in dioxane (4 mL) was refluxed for
3 days in the presence of DDQ (138 mg, 0.61 mmol).
After evaporation, water was added to the residue and
the mixture was filtered off. The solid residue was succes-
sively washed with water and EtOAc, and then was
dried to give 22 (37 mg, 0.091 mol, 27% yield) as a red
solid. Mp > 290 °C. IR (KBr) mC@C 1600 cmÀ1, mC@O
1720, 1775 cmÀ1, mNH 3150–3400 cmÀ1. HRMS (ESI+)
[M+Na]+ calcd for C24H13N3NaO4 430.0804, found
430.0803.
13C NMR (100 MHz, DMSO-d6): 31.8, 32.0, 69.1, 71.9
(CH2), 112.2, 114.9, 119.7, 123.8, 127.3, 127.5 (2C),
128.2 (2C), 130.9 (C tert arom), 105.1, 125.8, 135.1
(2C), 138.7, 139.5 (C quat), 173.2, 173.5 (C@O).
6.1.15. 3-(2,5-Dihydro-2,5-dioxo-pyrrol-3-yl)-5-(2-phen-
ylethyl)-1H-indole (17). A solution of DDQ (87 mg,
0.383 mmol) in dioxane (2.9 mL) was slowly added to a
solution of compound 14 (117 mg, 0.367 mmol) in diox-
ane (2.9 mL). The mixture was stirred at room tempera-
ture for 3 h. After filtration, the filtrate was evaporated
and the residue was purified by flash chromatography
(eluent: cyclohexane/EtOAc 7:3) to give 17 (102 mg,
0.322 mmol, 88% yield) as an orange solid. Mp 212 °C.
IR (KBr) mC@C 1605 cmÀ1, mC@O 1690, 1760 cmÀ1, mNH
3120–3460 cmÀ1. Mass (ESI+) 339 [M+Na]+.
1H NMR (400 MHz, DMSO-d6): 7.29 (1H, d,
J = 16.5 Hz), 7.32 (1H, t, J = 7.5 Hz), 7.44 (2H, t,
J = 7.5 Hz), 7.50 (1H, d, J = 16.5 Hz), 7.72 (2H, d,
J = 7.5 Hz), 7.79 (1H, d, J = 8.5 Hz), 8.04 (1H, d,
J = 8.5 Hz), 9.14 (1H, s), 11.59 (1H, s, NH), 11.65
(1H, s, NH), 12.84 (1H, s, NH).
1H NMR (400 MHz, DMSO-d6): 2.94–3.01 (2H, m),
3.02–3.08 (2H, m), 6.84 (1H, s), 7.17 (1H, d,
J = 8.5 Hz), 7.19–7.25 (1H, m), 7.29–7.34 (4H, m), 7.45
(1H, d, J = 8.5 Hz), 7.86 (1H, s), 8.35 (1H, d,
J = 2.0 Hz), 10.77 (1H, s, NH), 11.96 (1H, s, NH).
Due to its insolubility, the 13C NMR spectrum could not
be recorded.
6.1.18. 10-(2-Phenylethyl)-1,3,4,6-tetrahydro-2H,5H,7H-
dipyrrolo[3,4-a:3,4-c]carbazole-1,3,4,6-tetraone (23). A
mixture of 17 (79 mg, 0.234 mmol) and maleimide
(26.7 mg, 0.275 mmol) in p-xylene (4.3 mL) was refluxed
for 24 h. After cooling, the mixture was filtered off, and
the solid residue was washed with p-xylene and then was
dried to give 81 mg of intermediate 20. Compound 20
(30 mg) in TFA (56 lL, 0.73 mmol) was refluxed for
48 h. After evaporation, water was added to the residue.
The mixture was filtered off and the solid residue was
washed with water and then was dried to give 23
(24.0 mg, 0.059 mmol, 68% yield) as an orange solid.
Mp > 290 °C. IR (KBr) mC@C 1607 cmÀ1, mC@O 1721,
13C NMR (100 MHz, DMSO-d6): 37.4, 38.1 (CH2),
112.2, 114.9, 119.8, 123.9, 125.7, 128.2 (2C), 128.4
(2C), 130.9 (CH), 105.1, 125.8, 134.9, 135.2, 139.5,
141.9 (C quat), 173.2, 173.5 (C@O).
6.1.16.
2H,5H,7H-dipyrrolo[3,4-a:3,4-c]carbazole-1,3,4,6-tetra-
one (21). mixture of compound 16 (191 mg,
10-(3-Benzyloxypropyl)-1,3,4,6-tetrahydro-
A
0.53 mmol), maleimide (56.7 mg, 0.58 mmol) in p-xylene
(9 mL) was refluxed for 24 h. After cooling, the mixture
was filtered off, the solid residue was washed with p-xy-
lene and then was dried to give 223 mg of intermediate
19. Compound 19 (50 mg) in dioxane (3.6 mL) was stir-
red at 80 °C in the presence of TFA (265 lL, 3.44 mmol)
for 3 days. After evaporation, water was added to the
residue and the mixture was filtered off. The solid resi-
due was washed with water and then was dried to give
21 (41.5 mg, 0.092 mmol, 77% yield) as an orange solid.
1773 cmÀ1
,
mNH 3140–3460 cmÀ1
.
HRMS (ESI+)
[M+Na]+ calcd for C24H15N3NaO4 432.0960, found
432.0956.
1H NMR (400 MHz, DMSO-d6): 3.00–3.07 (2H, m),
3.09–3.17 (2H, m), 7.19–7.25 (1H, m), 7.29–7.35 (4H,
m), 7.58 (1H, dd, J1 = 8.5 Hz, J2 = 1.5 Hz), 7.69 (1H,
d, J = 8.5 Hz), 8.88 (1H, s), 11.55 (1H, s, NH), 11.58
(1H, s, NH), 12.68 (1H, s, NH).
Mp > 290 °C. IR (KBr) mC@O 1721, 1759, 1774 cmÀ1
,
mNH 3080–3590 cmÀ1. HRMS (ESI+) [M+Na]+ calcd
for C26H19N3NaO5 476.1222, found 476.1202.
1H NMR (400 MHz, DMSO-d6): 1.94–2.03 (2H, m),
2.90 (2H, t, J = 7.5 Hz), 3.53 (2H, t, J = 6.5 Hz), 4.53
13C NMR (100 MHz, DMSO-d6): 37.2, 37.5 (CH2),
112.5, 124.5, 125.8, 128.2 (2C), 128.4 (2C), 130.9 (C tert