Hydrochloric Acid → HCID 19771121, compound

Participants

Reaction Steps

To a solution of 1,3-dihydro-1-(5-chloro-2-hydroxyphenyl)-5-trifluoromethyl-2H-benzimidazol-2-one (0.2 g, 0.6 mmol) in absolute N,N-dimethylformamide (5 ml) was at room temperature added potassium hydroxide (2 pellets) and hydroxylamine-o-sulfonic acid (0.16 g, 1.3 mmol) The reaction was stirred over night, water was added (20 ml) and the mixture was acidified with 4 M hydrochloric acid. The crude crystalline product was collected by filtration and subjected to column chromatography using methylene chloride:methanol (19 1) as eluent. The fractions containing the product were concentrated in vacuo yielding the title compound as white crystals, M.p. 228°-230° C.

Provenance & Evidence