O-(2-Methylpropyl)hydroxylamine--hydrogen chloride (1/1) → methyl (2E)-2-(3-chloro-4-methylsulfonylphenyl)-2-(2-methylpropoxyimino)acetate

Participants

Reaction Conditions

Reaction Steps

(3-Chloro-4-methanesulfonyl-phenyl)-oxo-acetic acid methyl ester (prepared as in Example 1, 90 mg, 3.26 mmol) was stirred in methanol (7 mL) and warmed in a 70° C. oil bath. O-Isobutylhydroxylamine hydrochloride (511 mg, 4.07 mmol) was added. After 3 h, the reaction mixture was allowed to cool and concentrated in vacuo. Purification by flash column chromatography (Merck silica gel 60, 40-63 μm; 20% ethyl acetate/hexanes to 30% ethyl acetate/hexanes) afforded (E)-(3-chloro-4-methanesulfonyl-phenyl)-isobutoxyimino-acetic acid methyl ester as a white solid (395 mg, 35%): H1-NMR (400 MHz, CDCl3) δ=0.91 (6H, d, J=6.8 Hz), 2.04 (1H, m), 3.30 (3H, s), 3.91 (3H, s), 4.10 (2H, d, J=6.8 Hz), 7.50 (1H, dd, J=8.2 Hz, J=1.6 Hz), 7.61 (1H, d, J=1.6 Hz), 8.18 (1H, d, J=8.2 Hz).

Provenance & Evidence