1,3,4-Oxadiazole-linked bisindole derivatives
1
(87 % yield). Yellow solid; m.p.: 215–217 °C; H NMR
(300 MHz, DMSO-d6): d = 3.67 (s, 6H), 3.89 (s, 6H), 3.93
(s, 3H), 5.29 (s, 2H), 5.46 (s, 1H), 6.34 (s, 2H), 6.56 (s,
2H), 6. 70 (d, 2H, J = 9.02 Hz), 6.87 (d, 2H,
J = 9.02 Hz), 7.17 (d, 2H, J = 8.06 Hz), 7.21 (t, 2H),
7.28 (t, 2H), 7.56 (d, 2H, J = 8.34 Hz) ppm; 13C NMR
(75 MHz, DMSO-d6): d = 33.6, 41.4, 56.8, 59.9, 67.1,
105.6, 108.8, 118.5, 118.9, 119.8, 121.3, 124.5, 126.4,
126.8, 127.3, 141.4, 141.6, 144.7, 154.7, 154.9, 157.9,
162.1 ppm; MS (ESI): m/z = 615 ([M ? H]?).
2-[4-[Bis(1-methyl-1H-3-indolyl)methyl]phenoxymethyl]-
5-(4-nitrophenyl)-1,3,4-oxadiazole (12e, C34H27N5O4)
This compound 12e was prepared following the method
described for the preparation of the compound 12a,
employing 500 mg of 10 (1.4 mmol, 1.0 eq) with 234 mg
of 4-nitrobenzoic acid (11e, 1.4 mmol, 1.0 eq) and 15 cm3
POCl3 (1.6 mmol, 1.15 eq). The crude product was puri-
fied by column chromatography with ethyl acetate/n-
hexane (3:7) to afford 521 mg pure compound 12e (80 %
yield). Yellow solid; m.p.: 220–222 °C; 1H NMR
(300 MHz, DMSO-d6): d = 3.75 (s, 6H), 5.30 (s, 2H),
5.62 (s, 1H), 6.29 (s, 2H), 6.72 (d, 2H, J = 8.03 Hz), 6.95
(d, 2H, J = 8.03 Hz), 7.23 (d, 2H, J = 8.23 Hz), 7.30 (t,
2H), 7.46 (t, 2H), 7.78 (d, 2H, J = 9.23 Hz), 7.89 (d, 2H,
J = 8.10 Hz), 8.23 (d, 2H, J = 8.23 Hz) ppm; 13C NMR
(75 MHz, DMSO-d6): d = 32.6, 41.2, 67.3, 108.6, 117.9,
118.9, 119.8, 120.3, 124.4, 124.8, 125.7, 125.3, 125.8,
126.0, 126.8, 134.8, 139.8, 144.9, 148.5, 156.7, 158.7,
163.4 ppm; MS (ESI): m/z = 570 ([M ? H]?).
2-[4-[Bis(1-methyl-1H-3-indolyl)methyl]phenoxymethyl]-
5-(4-methoxyphenyl)-1,3,4-oxadiazole
(12c, C35H30N4O3)
This compound 12c was prepared following the method
described for the preparation of the compound 12a,
employing 500 mg of 10 (1.4 mmol, 1.0 eq) with 213 mg
of 4-methoxybenzoic acid (11c, 1.4 mmol, 1.0 eq) and
15 cm3 POCl3 (1.6 mmol, 1.15 eq). The crude product was
purified by column chromatography with ethyl acetate/n-
hexane (3:7) to afford 560 mg pure compound 12c (89 %
yield). Yellow solid; m.p.: 178–180 °C; 1H NMR
(300 MHz, DMSO-d6): d = 3.66 (s, 6H), 3.89 (s, 3H),
5.31 (s, 2H), 5.43 (s, 1H), 6.29 (s, 2H), 6.56 (d, 2H,
J = 8.23 Hz), 6.64 (d, 2H, J = 8.23 Hz), 6.71 (d, 2H,
J = 9.23 Hz), 6.79 (d, 2H, J = 8.12 Hz), 6.84 (t, 2H), 6.90
(t, 2H), 6.99 (d, 2H, J = 8.03 Hz), 7.45 (d, 2H,
J = 9.23 Hz) ppm; 13C NMR (75 MHz, DMSO-d6):
d = 32.8, 41.3, 56.4, 67.1, 106.9, 116.4, 116.9, 118.3,
118.8, 119.3, 120.5, 123.8, 125.4, 125.7, 125.8, 141.2,
146.2, 155.4, 159.4, 162.6, 163.4 ppm; MS (ESI):
m/z = 555 ([M ? H]?).
2-[4-[Bis(1-methyl-1H-3-indolyl)methyl]phenoxymethyl]-
5-(3-nitrophenyl)-1,3,4-oxadiazole (12f, C34H27N5O4)
This compound 12f was prepared following the method
described for the preparation of the compound 12a,
employing 500 mg of 10 (1.4 mmol, 1.0 eq) with 227 mg
of 3-nitrobenzoic acid (11f, 1.4 mmol, 1.0 eq) and 15 cm3
POCl3 (1.6 mmol, 1.15 eq). The crude product was purified
by column chromatography with ethyl acetate/n-hexane
(3:7) to afford 534 mg pure compound 12f (82 % yield).
Yellow solid; m.p.: 227–229 °C; 1H NMR (300 MHz,
DMSO-d6): d = 3.63 (s, 6H), 5.36 (s, 2H), 5.39 (s, 1H),
6.29 (s, 2H), 6.38 (d, 2H, J = 8.05 Hz), 6.90 (d, 2H,
J = 8.22 Hz), 7.23 (d, 2H, J = 8.02 Hz), 7.29 (t, 2H), 7.45
(t, 2H), 7.49 (d, 2H, J = 8.44 Hz), 7.61 (t, 1H), 8.00 (d, 1H,
J = 9.01 Hz), 8.20 (d, 1H, J = 10.35 Hz), 8.49 (s, 1H)
ppm; 13C NMR (75 MHz, DMSO-d6): d = 33.4, 41.2, 67.3,
106.9, 117.8, 119.6, 119.9, 120.8, 121.9, 124.4, 124.9, 125.4,
125.6, 125.9, 130.9, 131.9, 141.0, 144.8, 148.9, 155.8, 159.3,
163.9 ppm; MS (ESI): m/z = 570 ([M ? H]?).
2-[4-[Bis(1-methyl-1H-3-indolyl)methyl]phenoxymethyl]-
5-(3-methoxyphenyl)-1,3,4-oxadiazole
(12d, C35H30N4O3)
This compound 12d was prepared following the method
described for the preparation of the compound 12a,
employing 500 mg of 10 (1.4 mmol, 1.0 eq) with 213 mg
of 3-methoxybenzoic acid (11d, 1.4 mmol, 1.0 eq) and
15 cm3 POCl3 (1.6 mmol, 1.15 eq). The crude product was
purified by column chromatography with ethyl acetate/n-
hexane (2:8) to afford 511 mg pure compound 12d (81 %
yield). Yellow solid; m.p.: 189–191 °C; 1H NMR
(300 MHz, DMSO-d6): d = 3.70 (s, 6H), 3.78 (s, 3H),
5.28 (s, 2H), 5.35 (s, 1H), 6.29 (s, 2H), 6.65 (d, 2H,
J = 8.10 Hz), 6.70 (d, 1H, J = 8.23 Hz), 6.78 (s, 1H),
6.99 (d, 2H, J = 8.10 Hz), 7.09 (d, 1H, J = 9.01 Hz), 7.25
(d, 2H, J = 8.23 Hz), 7.27 (t, 2H), 7.30 (t, 2H), 7.35 (d,
2H, J = 8.23 Hz), 7.40 (t, 1H) ppm; 13C NMR (75 MHz,
DMSO-d6): d = 32.7, 39.9, 56.4, 66.5, 107.6, 107.9, 117.9,
118.7, 118.9, 119.4, 119.9, 123.8, 125.7, 125.8, 125.9,
126.2, 130.9, 131.2, 140.8, 146.0, 156.3, 159.3, 161.7,
162.7 ppm; MS (ESI): m/z = 555 ([M ? H]?).
4-[5-[4-[Bis(1-methyl-1H-3-indolyl)methyl]-
phenoxymethyl]-1,3,4-oxadiazol-2-yl]phenol
(12g, C34H28N4O3)
This compound 12g was prepared following the method
described for the preparation of the compound 12a,
employing 500 mg of 10 (1.4 mmol, 1.0 eq) with 193 mg
of 4-hydroxybenzoic acid (11g, 1.4 mmol, 1.0 eq) and
15 cm3 POCl3 (1.6 mmol, 1.15 eq). The crude product was
purified by column chromatography with ethyl acetate/n-
hexane (4:6) to afford 546 mg pure compound 12g (89 %
yield). Yellow solid; m.p.: 234–236 °C; 1H NMR
(300 MHz, DMSO-d6): d = 3.69 (s, 6H), 5.27 (s, 2H),
5.31 (s, 1H), 5.38 (s, 2H), 6.72 (d, 2H, J = 8.90 Hz), 6.89
(d, 2H, J = 8.04 Hz), 6.99 (d, 2H, J = 8.90 Hz), 7.24 (d,
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