Hydrochloric Acid → 5,6-dichloro-2-(2,2,2-trifluoro-ethyl)-1H-benzimidazole

Participants

Reaction Conditions

Reaction Steps

4,5-Dichloro-benzene-1,2-diamine (10.0114 g; 56.5520 mmoles) and 3,3,3-trifluoro-propionic acid (7.5 mL; 84.9 mmoles) were combined with 6N HCl (20 mL; 120 mmoles) and heated to 108° C. for 18 hrs. The reaction mixture was cooled to room temperature, diluted with ethyl acetate (200 mL) and water (200 mL), then sodium bicarbonate (15.15 g; 180.3 mmoles) was added slowly and in portions to quench the reaction. The aqueous layer was separated and extracted with ethyl acetate (3×60 mL). The extracts were combined, washed with water (60 mL) and brine (60 mL), then dried over Na2SO4. The filtrate was concentrated in vacuo to yield a crude brown solid. A sample of the crude brown solid was purified by column chromatography (SiO2; 100% CH2Cl2) to yield the title compound as a light brown solid.

Provenance & Evidence