Synthesis
O-phenylenediamine was dissolved in a 1:1 mixture of methanol and water, trifluoroacetic acid was added, and the reaction was carried out at 50 for .
2 hours; after cooling to room temperature, concentrated under reduced pressure to remove methanol, the remaining aqueous phase was added to an aqueous sodium hydroxide solution, ethyl acetate was added to extract twice, the organic layers after extraction were combined, and the organic phases were washed with purified water, saturated saline, dried with anhydrous magnesium sulfate, pumped and filtered, spun-dried under reduced pressure to remove the organic solvent, and the residue was recrystallized with ethanol and water, to obtain the product 2-(trifluoromethyl)benzimidazole.
