O-Phenylenediamine → Meta-Pyridyl 6-(1H-benzo[d]imidazol-2-yl)pyridin-2-amine

Participants

Reaction Steps

A suspension of 6-aminopyridine-2-carboxylic acid (1.12 g, 8.2 mmol) with 1,2-diaminobenzene (1.77 mg,16.4 mmol) was heated in 8 mL of PPA at 180 degree for 2 h. The reaction mixture was poured into 250 mL of ice-water and neutralized with 2 N NaOH (chilled) while vigorously stirred. The resulting precipitate was filtered to collect an off-white solid, which was washed with 20 mL warm water, dried and purified by chromatography using a 9:1 mixture of CH2Cl2 to MeOH (MS, M++H=211).

Provenance & Evidence