Table 5.

NDL-catalyzed synthesis of 2-aryl-1-arylmethyl-1H-benzo[d]imidazoles 3.^a

entry	Ar	product	t (min)	yieldc (%)	mp (°C)
					found	reported
1	phenyl: 2a	3a	10	98	128–131	133–134 [23]
2	4-methylphenyl: 2b	3b	10	98	127–128	128–129 [23]
3	4-tert-butylphenyl: 2c	3c	15	94	124–125	122–126 [25]
4	2,4-dimethylphenyl: 2d	3d	12	96	120–122	119–123 [25]
5	4-methoxyphenyl: 2e	3e	11	98	157–159	158–160 [23]
6	3,4-dimethoxyphenyl: 2f	3f	12	95	167–169	171–173 [24]
7	3,4,5-trimethoxyphenyl: 2g	3g	15	94	261–262	262–263 [22]
8b	2-hydroxyphenyl: 2h	3h	10	98	167–168	160–162 [23]
9b	2-hydroxy-3-ethoxyphenyl: 2i	3i	12	96	285–287	–
10	4-hydroxy-3-methoxyphenyl: 2j	3j	12	96	181–183	184–186 [24]
11	4-hydroxy-3-ethoxyphenyl: 2k	3k	10	97	205–207	200–201 [26]
12	4-nitrophenyl: 2l	3l	10	98	190–192	189–191 [23]
13	4-fluorophenyl: 2m	3m	10	98	108–109	110–112 [23]
14	4-chlorophenyl: 2n	3n	10	98	138–140	137–139 [23]
15	4-bromophenyl: 2o	3o	12	96	158–160	160–162 [23]
16	2-furanyl: 2p	3p	15	95	90–92	88–89 [23]
17	2-thienyl: 2q	3q	13	96	149–150	150–152 [23]

^aReaction conditions: o-phenylenediamine (1, 1.0 mmol), aldehyde (2, 2.0 mmol), NDL (5.0 wt %), EtOH/H₂O 1:1 (3.0 mL), USI, 45–50 °C. ^bThe reaction stopped at the bisimine I, i.e., 3h/i stage. ^cIsolated yield.