Triethylamine → 5-(Ethylthio)carbonyloxy-1-methylpyrazol-4-yl 3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)phenyl ketone

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Reaction Steps

The crude 5-hydroxy-1-methylpyrazol-4-yl 3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)phenyl ketone obtained in the same manner as the above step (3) was dissolved in anhydrous THF (10 mL), and triethylamine (190 mg) and 96% S-ethyl chlorothiolformate (151 mg) were added, followed by stirring for 1 hour at room temperature. Ethyl acetate (200 mL) was added to the reaction mixture, and the mixture was washed twice with a saturated brine. The organic layer was dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=1:1) to obtain the desired product (250 mg).

Provenance & Evidence