O-Phenylenediamine → 2-(1,3-benzodioxol-5-yl)-1H-benzimidazole

Participants

Reaction Steps

A solution of 50 g (0.34 mol) of piperonal and 37 g (0.34 mol) of phenylenediamine in 0.3 L of nitrobenzene was stirred under reflux for 12 hours. The resulting mixture was concentrated in vacuo. The solid residue was collected via filtration, and rinsed with ether to give 39.6 g (49%) of desired material as an off-white solid: 1H NMR (CDCl3) δ 5.96 (s, 2H), 6.79 (d, J=8.5 Hz, 1H), 7.17-7.30 (m, 2H), 7.50-7.65 (m, 4H), 8.80-9.40 (br s, 1H).

Provenance & Evidence