Pyridine → 1-{2-(2-Fluoro-phenyl)-2-[hydroxyimino]-ethyl}-3-isopropenyl-1,3-dihydro-benzimidazol-2-one

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 1-[2-(2-fluoro-phenyl)-2-oxo-ethyl]-3-isopropenyl-1,3-dihydro-benzimidazol-2-one (1.3 g, 4.2 mmol) in ethanol (50 ml) was added hydroxylamine hydrochloride (0.84 g, 12.2 mmol) followed by pyridine (1.7 ml, 21.0 mmol) at ambient temperature. The resulting mixture was warmed to 80° C. for 6 h, cooled to ambient temperature and concentrated. The remaining residue was diluted with water, 1M HCl and ethyl acetate. The layers were separated and the aqueous phase was extracted once more with ethyl acetate. The combined organics were dried (MgSO4), filtered and concentrated to give the crude product which was purified via column chromatography (silica gel, 50% EtOAc/hexanes). The product-containing fractions were combined and concentrated to give 1.0 g (73%) of the desired product as an oil which solidified on standing.

Provenance & Evidence