Copper-Catalyzed, One-Pot, Three-Component Synthesis of Benzimidazoles by Condensation and C–N Bond Formation

Abstract

Benzimidazoles were synthesized by the copper-catalyzed, one-pot, three-component reaction of 2-haloanilines, aldehydes, and NaN(3). The reaction was optimized when 2-iodo- or 2-bromoanilines (1.0 equiv), aldehydes (1.2 equiv), NaN(3) (2.0 equiv), 5 mol% of CuCl, and 5 mol % of TMEDA were reacted in DMSO at 120 °C for 12 h. Good yields resulted, and the reaction showed tolerance toward functional groups such as ester, nitro, and chloro. Aliphatic and heteroaromatic aldehydes also afforded the desired products in moderate to good yields.

Catalysis by FeF3 in water: a green synthesis of 2-substituted 1,3-benzazoles and 1,2-disubstituted benzimidazoles

“…Prompted by the fact that 1,2-disubstituted benzimidazoles 10 can be accessed by direct one-step condensation of 1,2-phenylenediamines with aryl aldehydes 13 we decided to explore the potential of the present FeF 3 catalyzed reaction in the synthesis of these compounds in a single pot. Accordingly, 2.0 equiv of aldehyde was reacted with 1.0 equiv of 1, [2][3][4][5][6][7][8][9][10][11][12][13][14][15] phenylenediamines under the condition as mentioned earlier (entry 3, Table 1). To our satisfaction the reaction proceeded smoothly to give the desired 1,2-disubstituted benzimidazoles (4) in good yields (Table 3).…”

The efficient o-benzenedisulfonimide catalysed synthesis of benzothiazoles, benzoxazoles and benzimidazoles

“…Pale brown solid; mp 293-294 °C (EtOH; lit. 36 292-294 °C).Yield: 92% (1.79 g) from 2c and 8a; 87% (1.68 g) from 2c and 5a. …”

Structure activity relationship (SAR) study of benzimidazole scaffold for different biological activities: A mini-review

“…One pot reaction starting materials used were 2-haloanilines, aldehydes, NaN 3 , and CuCl (J) in catalytic amount [35]. 2-substituted benzimidazoles were synthesized and at present are also undergoing by various different procedures using different catalyst viz., Bahrami et al in 2007 carried out synthesis of 2-substituted benzimidazoles by one-pot condensation of o-phenylenediamines with aryl aldehydes using H 2 O 2 and HCl (K) in acetonitrile [36].…”