Hydrochloric Acid → Benzimidazole, 5,6-dichloro-2-pentafluoroethyl-

Participants

Reaction Conditions

Reaction Steps

4,5-Dichloro-benzene-1,2-diamine (2.01 g; 11.4 mmoles) and 2,2,3,3,3-pentafluoro-propionic acid (1.80 mL; 17.3 mmoles) were suspended in 6N HCl (10 mL; 60 mmoles) under a nitrogen atmosphere. The reaction was stirred vigorously and heated to 108° C. for 18 hrs, then cooled to room temperature. The reaction was diluted with water (60 mL) and with ethyl acetate (60 mL), then sodium bicarbonate (7.59 g; 90.3 mmoles) was added slowly and in portions to quench the reaction. The aqueous layer was separated and extracted with ethyl acetate (3×30 mL). The extracts were combined, washed with water (30 mL) and brine (30 mL), then dried over Na2SO4. The filtrate was concentrated in vacuo to yield a crude brown solid which was then purified by column chromatography (SiO2; 100% CH2Cl2) to yield the title compound as a light tan solid.

Provenance & Evidence