Methanol → (3-Chloro-4-methanesulfonyl-phenyl)-oxo-acetic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

(3-Chloro-4-methylsulfanyl-phenyl)-oxo-acetic acid methyl ester (prepared as in PCT WO 2004/052869 A1, Example 1, 1.89 g, 7.72 mmol) and oxone (14.26 g, 23.3 mmol) were combined in a mixture of water (4 mL) and methanol (40 mL) and stirred for 4 h. The methanol was evaporated in vacuo and the remaining mixture was treated with water (30 mL) and extracted with ethyl acetate (3×40 mL). The combined organic phases were dried over magnesium sulfate and evaporated in vacuo. The residue was purified by flash column chromatography (Merck silica gel 60, 40-63 μm; 50% ethyl acetate/hexanes) to afford (3-chloro-4-methanesulfonyl-phenyl)-oxo-acetic acid methyl ester (1.27 g, 60%) as a white solid: H1-NMR (400 MHz, CDCI3) δ=3.32 (3H, s), 4.03 (3H, s), 8.14 (1H, dd, J=8.0 Hz, J=1.6 Hz), 8.23 (1H, d, J=1.6 Hz), 8.30 (1H, d, J=8.0 Hz).

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