The Journal of Organic Chemistry
Article
69.1, 55.2, 21.5; HRMS (ESI+) calcd for C23H21NNaO4S [M + Na]+
430.1089, found 430.1125.
137.8, 135.3, 134.6, 132.0, 131.7, 131.4, 131.3, 130.4, 129.5, 128.8,
128.6, 128.3, 127.9, 127.7, 127.0, 126.7, 126.4, 126.3, 121.6, 115.8,
115.5, 69.7, 21.6; HRMS (ESI+) calcd for C26H20FNNaO3S [M +
Na]+ 468.1046, found 468.1078.
(E)-2-(4-Fluorobenzylidene)-1-(toluene-4-sulfonyl)indolin-3-ol
(6i): colorless solid (120.1 mg, 62% yield); mp 132−134 °C; IR (KBr)
3529, 1599, 1508, 1469, 1355, 1230, 1167, 1087, 1004 cm−1; 1H NMR
(CDCl3, 300 MHz) δH 7.89 (d, J = 8.1 Hz, 1H), 7.66−7.61 (m, 2H),
7.50 (d, J = 8.4 Hz, 2H), 7.42−7.40 (m, 2H), 7.33 (d, J = 7.5 Hz, 1H),
7.22−7.17 (m, 3H), 7.06 (t, J = 8.7 Hz, 2H), 5.07 (d, J = 10.5 Hz, 1H),
2.35 (s, 3H), 0.39 (d, J = 10.2 Hz, 1H); 13C NMR (CDCl3, 75 MHz)
δC 164.2, 160.9, 141.9, 141.0, 139.7, 133.4, 132.2, 131.2, 131.1, 130.9,
130.9, 130.3, 129.5, 127.4, 125.9, 125.3, 124.6, 118.6, 115.7, 115.4,
69.1, 21.5; HRMS (ESI+) calcd for C22H18FNNaO3S [M + Na]+
418.0889, found 418.0834.
(E)-2-Benzylidene-1-(toluene-4-sulfonyl)benz[g]indolin-3-ol (6j):
colorless solid (100.5 mg, 48% yield); mp 177−179 °C; IR (KBr)
3542, 3059, 1590, 1492, 1443, 1353, 1166, 1082, 1009 cm−1; 1H NMR
(CDCl3, 300 MHz) δH 8.69 (d, J = 8.4 Hz, 1H), 7.88 (d, J = 7.8 Hz,
1H), 7.77 (d, J = 8.1 Hz, 1H), 7.65−7.54 (m, 4H), 7.43−7.35 (m,
7H), 7.20 (d, J = 7.8 Hz, 2H), 5.06 (d, J = 11.1 Hz, 1H), 2.39 (s, 3H),
0.61 (d, J = 11.1 Hz, 1H); 13C NMR (CDCl3, 75 MHz) δC 145.2,
141.2, 137.8, 135.3, 134.3, 132.2, 131.9, 129.5, 128.9, 128.7, 128.6,
128.3, 128.3, 127.9, 126.9, 126.8, 126.5, 126.2, 121.6, 69.9, 21.6;
HRMS (ESI+) calcd for C26H21NNaO3S [M + Na]+ 450.1140, found
450.1139.
(E)-2-(4-(Trifluoromethyl)benzylidene)-1-(toluene-4-sulfonyl)-
benz[g]indolin-3-ol (6k): colorless solid (131.1 mg, 54% yield); mp
166−168 °C; IR (KBr) 3535, 1588, 1362, 1327, 1168, 1124, 1074,
1021 cm−1; 1H NMR (CDCl3, 600 MHz) δH, 8.69 (d, J = 8.4 Hz, 1H),
7.89 (d, J = 8.4 Hz, 1H), 7.78 (d, J = 8.4 Hz, 1H), 7.76 (d, J = 7.8 Hz,
2H), 7.66−7.64 (m, 3H), 7.59 (t, J = 7.2, Hz, 1H), 7.42 (d, J = 8.4 Hz,
1H), 7.38 (s, 1H), 7.34 (d, J = 7.8 Hz, 2H), 7.21 (d, J = 8.4 Hz, 2H),
5.02 (d, J = 11.4 Hz, 1H), 2.41 (s, 3H), 0.56 (d, J = 11.4 Hz, 1H); 13C
NMR (CDCl3, 75 MHz) δC 145.5, 143.2, 137.8, 137.7, 135.4, 132.0,
131.3, 129.7, 129.6, 128.8, 128.5, 128.0, 127.2, 127.1, 126.7, 126.4,
125.5, 125.5, 121.5, 69.7, 21.7; HRMS (ESI+) calcd for
C27H20F3NNaO3S [M + Na]+ 518.1014, found 518.0988.
General Procedure for the Synthesis of Indoles 7. 2-
Arylideneindolin-3-ol 6 (0.26 mmol) and cyclohexene (3 mL) were
dissolved in dry EtOH (10 mL), and the resulting mixture was
degassed by bubbling nitrogen for about 30 min. Next, 10% Pd/C
(21.2 mg, 0.02 mmol, 10 mol %) was added, and the whole reaction
mixture was refluxed under nitrogen for 5.5−7 h. After completion
(TLC) of the reaction, the catalyst was filtered off and washed with
ethyl acetate; the filtrate was evaporated under reduced pressure. The
resulting crude product was purified through silica gel (100−200
mesh) column chromatography (ethyl acetate−petroleum ether) to
obtain the pure product 7.
2-Benzyl-1-(toluene-4-sulfony)-1H-indole (7a): colorless solid
(89.2 mg, 95% yield); mp 127−129 °C; IR (KBr) 3067, 2958, 2913,
1595, 1494, 1448, 1370, 1264, 1174, 1142, 1143, 1091, 1048 cm−1; 1H
NMR (CDCl3, 600 MHz) δH 8.15 (d, J = 8.4 Hz, 1H), 7.53 (d, J = 8.4
Hz, 2H), 7.35 (d, J = 7.8 Hz, 1H), 7.31- 7.28 (m, 2H), 7.27−7.24 (m,
2H), 7.21 (d, J = 7.2 Hz, 2H), 7.18 (t, J = 7.5 Hz, 1H), 7.13 (d, J = 7.8
Hz, 2H), 6.09 (s, 1H), 4.35 (s, 2H), 2.32 (s, 3H); 13C NMR (CDCl3,
150 MHz) δC 144.6, 140.9, 138.0, 137.2, 136.1, 129.7, 129.4, 128.5,
126.6, 126.4, 124.0, 123.4, 120.3, 114.7, 110.8, 35.2, 21.5; HRMS
(ESI) calcd for C22H19NNaO2S [M + Na]+ 384.1034, found 384.1079.
2-(4-Methylbenzyl)-1-(toluene-4-sulfony)-1H-indole (7b): color-
less solid (82.0 mg, 84% yield); mp 99−101 °C; IR (KBr) 3026,
2913, 1911, 1594, 1515, 1448, 1372, 1300, 1172, 1143, 1092, 1045
cm−1; 1H NMR (CDCl3, 600 MHz) δH 8.15 (d, J = 7.8 Hz, 1H), 7.54
(d, J = 8.4 Hz, 2H), 7.34 (d, J = 7.8 Hz, 1H), 7.26−7.23 (m, 1H),
7.19−7.17 (m, 1H), 7.14 (d, J = 8.4 Hz, 2H), 7.11−7.08 (m, 4H), 6.08
(s, 1H), 4.30 (s, 2H), 2.35 (s, 3H), 2.33 (s, 3H); 13C NMR (CDCl3,
150 MHz) δC 144.6, 141.3, 137.2, 136.2, 134.9, 129.7, 129.4, 129.3,
129.1, 126.4, 123.9, 123.4, 120.2, 114.7, 110.7, 34.9, 21.5, 21.1; MS
(ESI+) m/z 398.26 [M + Na]+. Anal. Calcd for C23H21NO2S: C,
73.57; H, 5.64; N, 3.73. Found: C, 73.60; H, 5.61; N, 3.78.
(E)-2-(2-Methyl-4-nitrobenzylidene)-1-(toluene-4-sulfonyl)benz-
[g]indolin-3-ol (6l): brown solid (123.9 mg, 52% yield); mp 167−169
°C; IR (KBr) 3583, 2923, 2857, 1591, 1513, 1440, 1341, 1167, 1083
cm−1; 1H NMR (CDCl3, 600 MHz) δH 8.70 (d, J = 8.4 Hz, 1H), 8.07
(brd, 2H), 7.89 (t, J = 9 Hz, 2H), 7.78 (d, J = 8.4 Hz, 1H), 7.66 (t, J =
7.8 Hz, 1H), 7.59 (t, J = 6.6 Hz, 1H), 7.43 (brd, 1H), 7.39 (s, 1H),
7.37 (d, J = 8.4 Hz, 2H), 7.24 (d, J = 8.4 Hz, 2H), 4.90 (d, J = 10.8 Hz,
1H), 2.46 (s, 3H), 2.42 (s, 3H), 0.64 (d, J = 11.4 Hz, 1H); 13C NMR
(CDCl3, 150 MHz) δC 147.3, 145.6, 144.7, 139.9, 138.8, 137.9, 135.4,
132.2, 131.1, 130.2, 129.7, 128.7, 128.6, 128.1, 127.2, 126.6, 126.5,
126.3, 124.9, 124.8, 121.4, 121.2, 69.9, 21.7, 20.4; MS (ESI+) m/z
509.19 [M + Na]+, 525.16 [M + K]+. Anal. Calcd for C27H22N2O5S: C,
66.65; H, 4.56; N, 5.76; Found: C, 66.68; H, 4.59; N, 5.81.
(E)-2-(3-Methoxybenzylidene)(toluene-4-sulfonyl)benz[g]indolin-
3-ol (6m): colorless solid (118.8 mg, 53% yield); mp 159−161 °C; IR
(KBr) 3545, 3055, 1577, 1487, 1437, 1358, 1271, 1165, 1082, 1015
cm−1; 1H NMR (CDCl3, 600 MHz) δH 8.68 (d, J = 9.0 Hz, 1H), 7.88
(d, J = 8.4 Hz, 1H), 7.76 (d, J = 8.4 Hz, 1H), 7.64 (td, J = 8.4, 1.2 Hz,
1H), 7.58 (t, J = 7.8 Hz, 1H), 7.42 (d, J = 8.4 Hz, 1H), 7.36 (d, J = 8.4
Hz, 2H), 7.32 (t, J = 7.8 Hz, 3H), 7.20 (d, J = 7.8 Hz, 3H), 6.90 (dd, J
= 7.8, 2.4 Hz, 1H), 5.08 (d, J = 10.8 Hz, 1H), 3.83 (s, 3H), 2.39 (s,
3H), 0.65 (d, J = 10.8 Hz, 1H); 13C NMR (CDCl3, 75 MHz) δC 159.7,
145.2, 141.4, 137.8, 135.7, 135.3, 132.2, 131.9, 129.6, 129.5, 128.9,
128.7, 128.3, 127.9, 126.9, 126.7, 126.5, 126.2, 122.0, 121.6, 114.6,
114.2, 69.9, 55.3, 21.6; HRMS (ESI+) calcd for C27H23NNaO4S [M +
Na]+ 480.1245, found 480.1235.
2-(4-Trifluoromethylbenzyl)-1-(toluene-4-sulfonyl)-1H-indole
(7c): yellow amorphous solid (101.6 mg, 91% yield); IR (KBr) 2925,
2855, 1918, 1727, 1597, 1449, 1370, 1324, 1259, 1169, 1120 cm−1; 1H
NMR (CDCl3, 600 MHz) δH 8.17 (d, J = 8.4 Hz, 1H), 7.50 (d, J = 8.4
Hz, 2H), 7.45 (d, J = 8.4 Hz, 2H), 7.41 (d, J = 7.8 Hz, 1H), 7.31−7.29
(m, 1H), 7.29 (d, J = 8.4 Hz, 2H), 7.22 (td, J = 7.5, 1.2 Hz, 1H), 7.09
(d, J = 7.8 Hz, 2H), 6.23 (s, 1H), 4.43 (s, 2H), 2.32 (s, 3H); 13C NMR
(CDCl3, 150 MHz) δC 144.7, 142.2, 139.2, 137.3, 135.9, 129.7, 129.5,
129.1, 126.2, 125.3, 125.3, 125.3, 125.3, 124,4, 123.6, 120.4, 114.7,
111.3, 34.9, 21.4; HRMS (EI+) calcd for C23H18F3NO2S [M]+
429.1010, found 429.1010.
2-(4-Bromobenzyl)-1-(toluene-4-sulfonyl)-1H-indole (7d): color-
less solid (87.0 mg, 76% yield); mp 114−115 °C; IR (KBr) 2912,
1
1594, 1449, 1370, 1175, 1143, 1091, 1049 cm−1; H NMR (CDCl3,
600 MHz) δH 8.15 (d, J = 8.4 Hz, 1H), 7.53 (d, J = 8.4 Hz, 2H), 7.35
(d, J = 7.8 Hz, 1H), 7.31−7.29 (m, 2H), 7.27- 7.24 (m, 1H), 7.22 (d, J
= 7.2 Hz, 2H), 7.18 (t, J = 7.5 Hz, 1H), 7.14 (d, J = 7.8 Hz, 2H), 6.09
(s, 1H), 4.35 (s, 2H), 2.33 (s, 3H); 13C NMR (CDCl3, 150 MHz) δC
144.6, 141.0, 138.0, 137.2, 136.1, 129.7, 129.4, 128.5, 126.6, 126.4,
124.0, 123.4, 120.3, 114.7, 110.8, 35.2, 21.5; MS (ESI+) m/z 463.98
[M + Na]+. Anal. Calcd for C22H18BrNO2S: C, 60.01; H, 4.12; N, 3.18.
Found: C, 60.05; H, 4.09; N, 3.22.
2-(Thiophene-2-yl-methyl)-1-(toluene-4-sulfonyl)-1H-indole (7e):
yellow solid (81.2 mg, 85% yield); mp 103−104 °C; IR (KBr) 3067,
2924, 1595, 1446, 1370, 1300, 1210, 1172, 1142, 1090, 1043 cm−1; 1H
NMR (CDCl3, 600 MHz) δH 8.13 (dd, J = 8.4, 0.6 Hz, 1H), 7.54 (d, J
= 8.4 Hz, 2H), 7.39 (d, J = 7.2 Hz, 1H), 7.27−7.26 (m, 1H), 7.21−
7.18 (m, 2H), 7.15 (d, J = 8.4 Hz, 2H), 6.95 (dd, J = 4.8, 3.6 Hz, 1H),
6.91−6.90 (m, 1H), 6.33 (d, J = 0.6 Hz, 1H), 4.59 (s, 2H), 2.332 (s,
3H); 13C NMR (CDCl3, 150 MHz) δC 144.7, 140.5, 140.2, 137.1,
135.9, 129.8, 129.3, 126.8, 126.5, 126.4, 124.4, 124.2, 123.5, 120.5,
114.7, 110.6, 29.4, 21.5; MS (ESI+) m/z 389.91 [M + Na]+. Anal.
Calcd for C20H17NO2S2: C, 65.37; H, 4.66; N, 3.81. Found: C, 65.41;
H, 4.63; N, 3.85.
(E)-2-(4-Fluorobenzylidene)-1-(toluene-4-sulfonyl)benz[g]indolin-
3-ol (6n): colorless solid (122.2 mg, 56% yield); mp 181−183 °C; IR
(KBr) 3525, 3052, 1597, 1507, 1437, 1352, 1296, 1232, 1164, 1086,
1020 cm−1; 1H NMR (CDCl3, 300 MHz) δH 8.69 (d, J = 8.1 Hz, 1H),
7.89 (d, J = 7.8 Hz, 1H), 7.77 (d, J = 8.4 Hz, 1H), 7.66−7.60 (m, 5H),
7.42 (d, J = 8.4 Hz, 2H), 7.36−7.28 (m, 2H), 7.24 (d, J = 8.4 Hz, 2H),
7.09 (t, J = 8.7 Hz, 1H), 5.02 (d, J = 11.4 Hz, 1H), 2.40 (s, 3H), 0.53
(d, J = 11.4 Hz, 1H); 13C NMR (CDCl3, 75 MHz) δC 145.3, 140.6,
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dx.doi.org/10.1021/jo300458v | J. Org. Chem. 2012, 77, 5108−5119