WANG ET AL.
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1
(EtOAc–n‐hexane = 1:2); m.p. = 99–101 °C. H NMR
(CDCl3, 400 MHz, δ, ppm): 7.87 (d, J = 7.2 Hz, 1H),
7.72 (d, J = 8.0 Hz, 1H), 7.48 (d, J = 8.0 Hz, 2H),
7.39–7.31 (m, 3H), 7.19 (t, J = 7.6 Hz, 1H), 6.83 (s, 1H),
4.55 (q, J = 7.2 Hz, 2H), 4.40 (q, J = 7.2 Hz, 2H), 1.48 (t,
J = 7.2 Hz, 3H), 1.29 (t, J = 7.2 Hz, 3H). 13C NMR (CDCl3,
100 MHz, δ, ppm): 145.5, 143.1, 137.0, 134.5, 127.2, 122.8,
122.8, 121.1, 119.9, 110.0, 109.9, 104.8, 39.2, 38.9, 15.3,
15.1. HRMS‐EI (m/z) [M]+ calcd for C19H19N3: 289.1579,
found: 289.1578. Anal. Calcd for C19H19N3 (%): C, 78.86;
H, 6.62; N, 14.52; found (%): C, 78.95; H, 6.59; N, 14.47.
Calcd for C23H27N3 (%): C, 79.96; H, 7.88; N, 12.16;
found (%): C, 79.96; H, 7.80; N, 12.20.
4.4 | General Procedure for Suzuki–
Miyaura Coupling Reaction
All manipulations were carried out under nitrogen using
dried solvent. Arylboronic acid 8 (1.50 mmol), aryl halide
7 (1.00 mmol), K3PO4⋅H2O (3.00 mmol), ligands (as indi-
cated) and Pd(OAc)2 (as indicated) were charged into a
Schlenk tube. Dry 1,4‐dioxane (3.0 ml) was then added.
The mixture was stirred at the prescribed temperature
for the prescribed time. After completion of the reaction,
monitored by TLC, the reaction was quenched by water
(3.0 ml). The aqueous layer was extracted with EtOAc
(3 × 3.0 ml). The organic layer was dried over anhydrous
MgSO4 and then filtered. The solvent was evaporated
under reduced pressure and the corresponding crude
product of Suzuki–Miyaura coupling reaction was puri-
fied by chromatography.
4.3.2 | 1‐Propyl‐2‐(1‐propylindolyl)benz-
imidazole (1d)
2‐(1H‐indolyl)benzimidazole (1.00 g, 4.29 mmol), 1‐
bromopropane (1.56 ml, 17.2 mmol) and potassium
hydroxide (1.92 g, 34.3 mmol) were used to afford 1d
(0.89 g, 65%) as an orange oil. Rf = 0.7 (EtOAc–n‐hex-
1
ane = 1:2). H NMR (CDCl3, 400 MHz, δ, ppm): 7.89–
7.86 (m, 1H), 7.72 (d, J = 8.0 Hz, 1H), 7.47 (d,
J = 8.8 Hz, 1H), 7.37–7.31 (m, 4H), 7.19 (t, J = 8.0 Hz,
1H), 6.82 (s, 1H), 4.49 (t, J = 7.2 Hz, 2H), 4.29 (t,
J = 7.2 Hz, 2H), 1.90 (sextet, J = 7.6 Hz, 2H), 1.71 (sextet,
J = 7.6 Hz, 2H), 0.96 (t, J = 7.6 Hz, 3H), 0.77 (t,
J = 7.2 Hz, 3H). 13C NMR (CDCl3, 100 MHz, δ, ppm):
127.6, 123.2, 122.9, 122.6, 121.6, 120.8, 120.5, 120.4,
120.3, 119.4, 110.6, 110.5, 105.3, 46.6, 46.5, 46.3, 46.1,
24.0, 23.71, 23.65, 23.56, 23.0, 14.5, 11.5. HRMS‐EI (m/z)
[M]+ calcd for C21H23N3: 3117.1892, found: 317.1897.
Anal. Calcd for C21H23N3 (%): C, 79.46; H, 7.30; N,
13.24; found (%): C, 79.33; H, 7.49; N, 12.89.
ACKNOWLEDGEMENT
We thank the Ministry of Science and Technology of the
Republic of China (106WFA0550361) for financial
support.
ORCID
REFERENCES
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2‐(1H‐indolyl)benzimidazole (1.00 g, 4.29 mmol), 1‐
bromobutane (1.85 ml, 17.2 mmol) and potassium
hydroxide (1.92 g, 34.3 mmol) were used to afford 1e
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hexane = 1:2); m.p. = 55–57 °C. 1H NMR (CDCl3,
400 MHz, δ, ppm): 7.86–7.84 (m, 1H), 7.70 (d,
J = 8.0 Hz, 1H), 7.61 (dd, J = 8.0, 0.8 Hz, 2H),
7.37–7.39 (m, 3H), 7.18 (td, J = 8.0, 0.8 Hz, 1H),
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J = 7.2 Hz). 13C NMR (CDCl3, 100 MHz, δ, ppm):
146.0, 143.2, 137.6, 135.0, 127.8, 127.3, 122.9, 122.4,
121.3, 120.2, 120.0, 110.4, 110.2, 105.1, 44.5, 44.0,
32.2, 32.0, 20.1, 20.0, 13.7, 13.6. HRMS‐EI (m/z) [M]+
calcd for C23H27N3: 345.2205, found: 345.2195. Anal.
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