13676-49-8

59403-35-9

13676-49-8

The general procedure for the synthesis of 2-(3-aminophenyl)-5-aminobenzimidazole using the compound (CAS: 59403-35-9) as starting material was as follows: the prepared amide, 200 mL of acetic acid and 0.20 g of 5% Pd/C catalyst were added to a 500 mL autoclave. The reaction was carried out at 110 °C and 6 MPa hydrogen pressure for 4 hours. Upon completion of the reaction, the autoclave was cooled and filtered to recover the catalyst. About 150 mL of solvent was removed by distillation of the filtrate at atmospheric pressure under nitrogen protection. Subsequently, 100 mL of pure water was added to the remaining solution and the mixture was cooled to 20 °C. Upon filtration, 16.2 g of the target product 2-(3-aminophenyl)-5-aminobenzimidazole was obtained in 96.2% purity and 90.5% yield by HPLC.