O-Phenylenediamine → 2-(4-ethylphenyl)-1H-benzimidazole

Participants

Reaction Steps

5.5 g. of o-phenylenediamine, 7.6 g. of p-ethylbenzoic acid and 40 g. of polyphosphoric acid were heated at 160°-180° C. under nitrogen gas current with stirring for 4 hours. The reaction mixture was diluted with 400 ml. of water and then neutralized with sodium carbonate. The resulting crystals were filtered off, dried and recrystallized from ethyl acetate. 8.2 g. (73% of theory) of the product was obtained. M.P. 258°-258.4° C.

Provenance & Evidence