Phthalic Acid → 2-[2-(1H-benzimidazol-2-yl)phenyl]-1H-benzimidazole

Participants

Reaction Conditions

Reaction Steps

To a flask were added 50 g polyphosphoric acid. After heating to 90 C under nitrogen, a mixture of 2.7 g 1,2-phenylenediamine and 2.1 g phthalic acid were added. The reaction mixture was heated to 18° C. for 4 hours, then cooled to 130 C and poured into 150 ml water. The mixture was basified with aqueous ammonium hydroxide. After cooling to 5 C, the product was filtered and washed with water. After drying, 3.3 g of a gray solid remained.

Provenance & Evidence