Phosphorus oxychloride → 2-chloro-6-(trifluoromethyl)-1H-benzimidazole

Participants

Reaction Steps

A solution of the dihydrobenzoimidazol-2-one from step (b) above (2.02 g, 10 mmol) in POCl3 (30 mL) was heated at 95° C. for 16 h. The reaction mixture was cooled to room temperature, the solvent was removed in vacuo and the resulting oily residue subjected to azeotropic distillation with toluene (3×50 mL) at 50° C. The crude product was dissolved in EtOAc (50 mL), washed with brine (10 mL) then dried over Na2SO4 and filtered. The solvent was removed in vacuo and the residue was recrystallized from EtOAc/hexane to give the title compound.

Provenance & Evidence