## 3 Materials and Methods
### Synthesis  
#### Synthesis of the Starting Substrates  
Starting 1-methyl-1\(H\)-indole-3-carbaldehyde (**1b**), 1-ethyl-1\(H\)-indole-3-carbaldehyde (**1c**), 1-isopropyl-1\(H\)-indole-3-carbaldehyde (**1d**), 1-benzyl-1\(H\)-indole-3-carbaldehyde (**1f**), 1-\(n\)-butyl-1\(H\)-indole-3-carbaldehyde (**1g**), 5-bromo-1-methyl-1\(H\)-indole-3-carbaldehyde (**1p**) [47], 2-phenyl-1\(H\)-indole-3-carbaldehyde (**1h**), 2-(4-nitrophenyl)-1\(H\)-indole-3-carbaldehyde (**1i**), 2-(4-fluorophenyl)-1\(H\)-indole-3-carbaldehyde (**1j**), 2-(thiophen-2-yl)-1\(H\)-indole-3-carbaldehyde (**1k**), 2-(4-hydroxyphenyl)-1\(H\)-indole-3-carbaldehyde (**1l**), 2-(4-methoxyphenyl)-1\(H\)-indole-3-carbaldehyde (**1m**) [48], 1-phenyl-1\(H\)-indole-3-carbaldehyde (**1e**), 5-iodo-1\(H\)-indole-3-carbaldehyde (**1n**), 5-bromo-1\(H\)-indole-3-carbaldehyde (**1o**), 1-methyl-1\(H\)-pyrrole-2-carbaldehyde (**1l**) [49], benzofuran-2-carbaldehyde (**1q**) [50], 3-(4-fluorophenyl)-1-phenyl-1\(H\)-pyrazole-4-carbaldehyde (**1v**) [51], and 2-\(N\)-phenylbenzene-1,2-diamine (**2v**) [52] were synthesized according to a known procedure. Starting 4-chlorobenzene-1,2-diamine (**2b**), 4-fluorobenzene-1,2-diamine (**2c**), 4,5-dimethylbenzene-1,2-diamine (**2e**), 4-(trifluoromethylomethyl)benzene-1,2-diamine (**2f**), 4-methoxybenzene-1,2-diamine (**2g**), 4-methylbenzene-1,2-diamine (**2h**), 4,5-dichlorobenzene-1,2-diamine (**2i**), 4-nitrobenzene-1,2-diamine (**2j**), 3-methylbenzene-1,2-diamine (**2k**), 3,4-dimethylbenzene-1,2-diamine (**2p**), 3,4-difluorobenzene-1,2-diamine (**2q**), 4-[(3,4-diaminophenyl)methyl]benzene-1,2-diamine (**2w**), and phenazine-2,3-diamine (**2x**) were synthesized according to a known procedure [53]. \(N\)-Substituted phenylenediamines 2-\(N\)-methylbenzene-1,2-diamine (**2r**), 2-\(N\)-(propan-2-yl)benzene-1,2-diamine (**2s**), \(N\)-allyl-\(o\)-phenylenediamine (**2l**), and 2-\(N\)-benzylbenzene-1,2-diamine (**2u**) were synthesized according to a known procedure [54]. Starting 4-bromobenzene-1,2-diamine (**2d**), 3-bromo-5-chlorobenzene-1,2-diamine (**2l**), 3-bromo-5-methylbenzene-1,2-diamine (**2m**), 3-bromo-5-methoxybenzene-1,2-diamine (**2n**), and 3,5-dibromobenzene-1,2-diamine (**2o**) were synthesized according to a known procedure [55]. 3.2 General Procedure for the Synthesis of 1\(H\)-Benzo[\(d\)]imidazoles **3a**-  
(m, 4H) ppm; \({}^{13}\)C[\({}^{1}\)H] NMR (100 MHz, DMSO-\(d_{6}\)) \(\delta\) = 147.7, 136.5, 135.0 (br.s), 129.1, 124.1, 123.2, 122.8, 121.0, 120.3, 113.6, 112.5, and 102.5 ppm. _2-(1-Methyl-1H-indol-3-yl)-1H-benzo[d]imidazole_ (**3b**) [57]. A yield of 0.254 g (79%), 6 h, light-beige solid. Mp. = 214-216 \({}^{\circ}\)C (EtOH, lit. [57] 231-233 \({}^{\circ}\)C). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) = 8.38 (br.s, 1H), 8.34-8.29 (m, 1H), 7.75-7.71 (m, 2H), 7.69-7.66 (m, 1H), 7.45-7.36 (m, 4H), and 3.98 (s, 3H) ppm; \({}^{13}\)C[\({}^{1}\)H] NMR (100 MHz, DMSO-\(d_{6}\)) \(\delta\) = 146.5, 137.2, 133.8, 133.2 (brs), 124.2, 124.0, 123.2, 121.7, 120.0, 113.4, 111.2, 99.7, and 33.4 ppm. _2-(1-Ethyl-1H-indol-3-yl)-1H-benzo[d]imidazole_ (**3c**) [58]. A yield of 0.299 g (88%), 7 h, light-beige solid. Mp. = 245-247 \({}^{\circ}\)C, decomposition (DMAC/H\({}_{2}\)O), lit. [58] 248-249 \({}^{\circ}\)C). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) = 12.39 (br.s, 1H), 8.53-8.51 (m, 1H), 8.17 (s, 1H), 7.59-7.52 (m, 3H), 7.30-7.21 (m, 2H), 7.16-7.12 (m, 2H), 4.32 (q, \(J\) = 7.2 Hz, 2H), and 1.47 (t, \(J\) = 7.2 Hz, 3H) ppm; \({}^{13}\)C[\({}^{1}\)H] NMR (100 MHz, DMSO-\(d_{6}\)) \(\delta\) = 149.0, 136.1, 128.2, 125.6, 122.1, 121.5, 121.0, 120.3, 110.1, 105.9, 40.6, and 15.1 ppm. _2-(1-Isopropyl-1H-indol-3-yl)-1H-benzo[d]imidazole_ (**3d**). A yield of 0.350 g (98%), 7 h, light-beige solid. Mp. = 179 \({}^{\circ}\)C, decomposition (DMAC/H\({}_{2}\)O).