Research Article

A Simple, Efficient Synthesis of 2-Aryl Benzimidazoles Using Silica Supported Periodic Acid Catalyst and Evaluation of Anticancer Activity

Table 1

Reaction of 1 and 4g under various conditionsa.

453682.tab.001

EntryCatalyst (mol %) on silicaTemp.bTimeYield (%)c

1H5IO6 (20)rt15 min95
2H5IO6 (15)rt15 min70
3H5IO6 (10)rt15 min45
4H5IO6 (20)drt10 h28
5SiO2rt10 h12
6H5IO6 (20)60°C15 min94
7H5IO6 (15)60°C15 min67
8H5IO6 (10)60°C15 min47
9H5IO6 (20)d60°C10 h35
10SiO260°C10 h16

1,2-phenylenediamine 1 mmol, m-nitrobenzaldehyde 1 mmol catalyst (0.20 mmol supported on silica) in ACN.
bRoom temperature was 30–35°C.
cYields are measured after purification.
dH5IO6 which is not supported on silica.