O-Phenylenediamine → 2-(1,3-benzodioxol-5-yl)-1H-benzimidazole
Reaction equation
[CH:1]1[C:6]([CH:7]=O)=[CH:5][C:4]2[O:9][CH2:10][O:11][C:3]=2[CH:2]=1.[C:12]1([NH2:19])[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=1[NH2:18]>[N+](C1C=CC=CC=1)([O-])=O>[O:11]1[C:3]2[CH:2]=[CH:1][C:6]([C:7]3[NH:19][C:12]4[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=4[N:18]=3)=[CH:5][C:4]=2[O:9][CH2:10]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
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).