O-Phenylenediamine → 2-(6-methylpyridin-3-yl)-1H-benzimidazole

Participants

Reaction Steps

11.9 g. of o-phenylenediamine, 13.7 g. of 2-methylpyridine-5-carboxylic acid and 100 g. of polyphosphoric acid were stirred under a nitrogen gas current at 180° C. to 200° C. for 4 hours. To the reaction mixture were added 800 ml. of water and then a concentrated aqueous solution of sodium carbonate to neutrality. The resulting crystals were filtered off, dried and recrystallized from acetonitrile to give 15.7 g. of colorless needles of the product (75% of theory), M.P. 265.5°-266.0° C.

Provenance & Evidence