3-Fluoroacetophenone → (3-Fluoro-phenyl)-oxo-acetaldehyde oxime

Participants

Reaction Steps

To a mixture of selenium dioxide (58.3 g, 525 mmol) in 20 ml of water and 400 ml of 1,4-dioxane was added in one-portion 1-(3-fluoro-phenyl)-ethanone (69.0 g, 500 mmol). The mixture was refluxed overnight, then filtered through diatomaceous earth. The filtrate was added to an equal volume of water and adjusted to pH 4 with 5% aqueous sodium hydroxide. To this mixture was added acetone oxime (40.2 g, 550 mmol) and the mixture was stirred for 24 h. On dilution to 1.5 L with water, the mixture was extracted with ethyl acetate (2×400 ml), and the organic layer was washed with brine, dried with anhydrous sodium sulfate, and concentrated to give a oil residue, which was purified by flash chromatography on silica gel (eluting with pure Petroleum) to return title compound as a pale yellow solid (68.0 g, 81.4%). 1H NMR (DMSO-d6): δ 12.78 (s, 1H), 8.02 (s, 1H), 7.82-7.50 (m, 4H).

Provenance & Evidence