Quinone → 5,6-Dichloro-2-(3-fluoro-4-formylphenyl)benzimidazole

Participants

Reaction Steps

A mixture of 4-dimethoxymethyl-3-fluorobenzaldehyde (321 mg, 1.62 mmol), 4,5-dichloro-1,2-phenylenediamine (283 mg, 1.60 mg) and 1,4-benzoquinone (173 mg, 1.60 mmol) in methanol (10 mL) was heated to reflux for 2 h. The solvent was removed under reduced pressure. To the residue were added tetrahydrofuran (15 mL) and hydrochloric acid (1 mol/L; 1.6 mL), and the mixture was stirred at room temperature for 16 h. Water was added and the precipitated products were collected by filtration, followed by trituration with ether to afford 5,6-dichloro-2-(3-fluoro-4-formylphenyl)benzimidazole (132 mg, 26%).

Provenance & Evidence