P. Csomoꢀs et al. / Tetrahedron 63 (2007) 4983–4989
4987
1095, 1010, 979.8, 970.2, 935.5, 895, 850.8, 801.6, 765.5,
743.4, 726.1, 689.6, 668.5, 608, 522.7, 486.1, 422.5,
415.6. H NMR d (DMSO-d6): 10.91 (1H, br s, NH), 9.01
powder after trituration with n-hexane and a few drops of
diisopropyl ether.
1
(1H, t, J¼6.1 Hz, CONH), 8.07–7.95 (2H, m, H-20, H-60),
7.45 (1H, d, J¼8.0 Hz, H-4), 7.39–7.25 (3H, m, H-30, H-
50, H-7), 7.03 (1H, t, J¼7.8 Hz, H-6), 6.95 (1H, t,
J¼8.0 Hz, H-5), 6.29 (1H, s, H-3), 4.63 (2H, d, J¼6.1 Hz,
CH2); 13C NMR d (DMSO-d6): 165.3, 165.1, 137.1, 136.1,
130.7, 130.0 (2C), 127.9, 120.5, 119.4, 118.8, 115.2 (2C),
111.1, 99.0, 36.8, due to F,C-couplings, the signals of the
aryl group are doublets, 1J(F,C): 249.5 Hz, 2J(F,C):
4.1.5.1. 2-(Thiobenzoylaminomethyl)indole (14a). Yel-
low crystals, mp: 155–157 ꢀC, yield 89%. nmax (KBr disc)
3454, 3384, 3252, 3047, 1642, 1615, 1594, 1530, 1488,
1456, 1421, 1389, 1352, 1339, 1308, 1281, 1271, 1197,
1138, 1094, 1077, 1032, 999.7, 960.8, 924.6, 889.2, 849.7,
795.4, 771.3, 752.6, 737.7, 717.9, 690, 639.5, 567.1, 460.8,
431.4. 1H NMR d (DMSO-d6): 11.03 (1H, br s, NH), 10.68
(1H, t, J¼6.2 Hz, CSNH), 7.87–7.40 (6H, m, H-20, H-60, H-
30, H-50, H-40, H-4), 7.36 (1H, d, J¼8.1 Hz, H-7), 7.05 (1H,
t, J¼8.1 Hz, H-6), 6.96 (1H, t, J¼8.2 Hz, H-5), 6.38 (1H, s,
H-3), 5.10 (2H, d, J¼6.2 Hz, CH2); 13C NMR d (DMSO-
d6): 197.7, 141.0, 136.1, 134.6, 130.7, 127.9 (2C), 127.8,
127.4 (2C), 120.8, 119.6, 118.8, 111.1, 99.9, 43.6. Anal.
Calcd for C16H14N2S (266.37): C, 72.15; H, 5.30; N, 10.52;
S, 12.04. Found: C, 71.95; H, 5.41; N, 10.27; S, 12.28.
3
4
22.1 Hz, J(F,C): 9.2 Hz, J(F,C): 2.7 Hz. Anal. Calcd for
C16H13FN2O (268.29): C, 71.63; H, 4.88; N, 10.44. Found:
C, 71.67; H, 4.71; N, 10.62.
4.1.4.4. 2-(4-Methylbenzoylaminomethyl)indole (11d).
Light-brown crystals, mp: 190–192 ꢀC (from toluene), yield
95%. nmax (KBr disc) 3430, 3290, 3200, 3080, 3052, 3025,
2940, 2921, 2853, 1640, 1614, 1571, 1529, 1499, 1457,
1414, 1362, 1340, 1312, 1291, 1238, 1217, 1187, 1154,
1144, 1118, 1094, 1041, 1008, 979.7, 929.4, 893, 849.2,
831.6, 801.2, 773.5, 751.9, 738.6, 693.1, 670.6, 609.3,
511.2, 450, 440.6. 1H NMR d (DMSO-d6): 10.88 (1H, br s,
NH), 8.89 (1H, t, J¼6.0 Hz, CONH), 7.83 (2H, d, J¼7.5 Hz,
H-20, H-60), 7.44 (1H, d, J¼7.8 Hz, H-4), 7.34 (1H, d,
J¼7.5 Hz, H-7), 7.28 (2H, J¼7.5 Hz, H-30, H-50), 7.02 (1H,
t, J¼7.5 Hz, H-6), 6.94 (1H, t, J¼7.8 Hz, H-5), 6.28 (1H, s,
H-3), 4.61 (2H, d, J¼6.0 Hz, CH2), 2.35 (3H, s, CH3); 13C
NMR d (DMSO-d6): 166.2, 141.1, 137.3, 136.1, 131.5,
128.7 (2C), 127.9, 127.3 (2C), 120.5, 119.4, 118.7, 111.1,
98.9, 36.7, 20.9. Anal. Calcd for C17H16N2O (264.32): C,
77.25; H, 6.10; N, 10.60. Found: C, 77.11; H, 5.91; N, 10.82.
4.1.5.2. 2-(4-Chlorothiobenzoylaminomethyl)indole
(14b). Yellow crystals, mp: 156–158 ꢀC, yield 81%. nmax
(KBr disc) 3467, 3377, 3249, 3080, 3052, 2961, 2920,
1638, 1616, 1591, 1534, 1487, 1455, 1427, 1403, 1354,
1340, 1307, 1277, 1213, 1198, 1150, 1136, 1112, 1089,
1013, 960.5, 928.1, 834.7, 792.2, 752.2, 739.2, 722.1, 645.3,
631.5, 574.8, 567.1, 494.6, 433.5, 408.9. 1H NMR d
(DMSO-d6): 11.06 (1H, br s, NH), 10.77 (1H, t, J¼5.0 Hz,
CSNH), 7.85 (2H, d, J¼8.2 Hz, H-20, H-60), 7.51 (2H, d,
J¼8.2 Hz, H-30, H-50), 7.48 (1H, d, J¼7.9 Hz, H-4), 7.37
(1H, d, J¼8.1 Hz, H-7), 7.06 (1H, t, J¼8.1 Hz, H-6), 6.97
(1H, t, J¼7.9 Hz, H-5), 6.39 (1H, s, H-3), 5.09 (2H, d, J¼
4.9 Hz, CH2); 13C NMR d (DMSO-d6): 196.1, 139.6,
136.1, 135.5, 134.4, 129.3 (2C), 127.9 (2C), 127.8, 120.8,
119.6, 118.9, 111.1, 100.0, 43.7. Anal. Calcd for
C16H13ClN2S (300.81): C, 63.89; H, 4.36; N, 9.31; S,
10.66. Found: C, 63.76; H, 4.11; N, 9.54; S, 10.93.
4.1.4.5. 2-(2-Fluorobenzoylaminomethyl)indole (11e).
White crystals, mp: 138–141 ꢀC (from toluene), yield 57%.
nmax (KBr disc) 3453, 3311, 3085, 2927, 1643, 1615, 1531,
1481, 1455, 1433, 1416, 1360, 1338, 1302, 1262, 1210,
1161, 1148, 1097, 1042, 1010, 979.3, 952.8, 925, 840.3,
787.1, 750.4, 739.2, 726.2, 687.6, 662, 650.6, 618.9, 606.9,
4.1.5.3. 2-(4-Fluorothiobenzoylaminomethyl)indole
(14c). Yellow crystals, mp: 170–173 ꢀC, yield 75%. nmax
(KBr disc) 3378, 3245, 3053, 1599, 1538, 1504, 1456,
1427, 1410, 1353, 1340, 1307, 1289, 1271, 1247, 1212,
1197, 1166, 1137, 1107, 1088, 1013, 961.1, 928.6, 841.5,
815.9, 791.9, 751.9, 735.4, 658.8, 631.2, 574.6, 494.6, 468.5,
433.3. 1H NMR d (DMSO-d6): 11.02 (1H, br s, NH), 10.68
(1H, t, J¼5.0 Hz, CSNH), 7.94–7.84 (2H, m, H-20, H-60),
7.46 (1H, d, J¼7.8 Hz, H-4), 7.34 (1H, d, J¼8.0 Hz, H-7),
7.30–7.19 (2H, m, H-30, H-50), 7.04 (1H, t, J¼8.0 Hz, H-
6), 6.95 (1H, t, J¼7.8 Hz, H-5), 6.37 (1H, s, H-3), 5.07
(2H, d, J¼4.9 Hz, CH2); 13C NMR d (DMSO-d6): 196.2,
164.8, 137.4, 136.1, 134.5, 129.9 (2C), 127.8, 120.8, 119.6,
118.9, 114.8 (2C), 111.1, 100.0, 43.7, due to F,C-couplings,
the signals of the aryl group are doublets, 1J(F,C): 248.9 Hz,
2J(F,C): 21.8 Hz, 3J(F,C): 9.3 Hz, 4J(F,C): 2.7 Hz. Anal.
Calcd for C16H13FN2S (284.35): C, 67.58; H, 4.61; N,
9.85; S, 11.28. Found: C, 67.32; H, 4.42; N, 10.03; S, 11.51.
1
553.6, 538.1, 528.8, 502.9, 464.2, 438.3, 415.3. H NMR
d (DMSO-d6): 10.94 (1H, br s, NH), 8.79 (1H, t, J¼4.7 Hz,
CONH), 7.79–7.21 (6H, m, H-30, H-40, H-50, H-60, H-4, H-
7), 7.04 (1H, t, J¼7.8 Hz, H-6), 6.96 (1H, t, J¼8.1 Hz, H-
5), 6.32 (1H, s, H-3), 4.63 (2H, d, J¼4.7 Hz, CH2); 13C
NMR d (DMSO-d6): 163.7, 158.0, 136.8, 136.1, 132.5,
130.2, 127.9, 124.4, 123.9, 120.6, 119.5, 118.8, 116.2, 111.1,
99.0, 36.7, due to F,C-couplings, the signals of the aryl group
1
2
3
are doublets, J(F,C): 249.1 Hz, J(F,C): 22.1 Hz, J(F,C):
4
5
6
13.7 Hz, J(F,C): 8.7 Hz, J(F,C): 8.3 Hz, J(F,C): 3.1 Hz.
Anal. Calcd for C16H13FN2O (268.29): C, 71.63; H, 4.88;
N, 10.44. Found: C, 71.45; H, 4.59; N, 10.47.
4.1.5. General procedure for substituted 2-(thiobenzoyl-
aminomethyl)indole (14a–e) from benzamides 11a–e. To
a solution of substituted 2-(benzoylaminomethyl)indole
(11a–e) (4.0 mmol) in tetrahydrofuran (40 mL), Lawesson0s
reagent (0.96 g, 2.4 mmol) was added in one portion. The re-
action mixture was heated at reflux for 2 h. After evapora-
tion, the residue was taken up in ethyl acetate (40 mL) and
extracted with saturated sodium hyrogencarbonate solution
(20 mL), water (20 mL), dried (sodium sulfate), evaporated
and purified by column chromatography, using n-hexane/
ethyl acetate 4:1 as an eluent, to give 14a–e as a crystalline
4.1.5.4. 2-(4-Methylthiobenzoylaminomethyl)indole
(14d). Yellow crystals, mp: 154–156 ꢀC, yield 91%. nmax
(KBr disc) 3402, 3327, 2923, 1522, 1504, 1456, 1417,
1382, 1341, 1325, 1279, 1221, 1189, 1067, 926.7, 826.3,
1
809, 739.6, 723.8, 665, 639.8, 606.4, 413.3. H NMR d
(DMSO-d6): 11.02 (1H, br s, NH), 10.58 (1H, t, J¼4.9 Hz,
CSNH), 7.78 (2H, d, J¼7.9 Hz, H-20, H-60), 7.48 (1H, d,