Hydrochloric Acid → 6-(4-Fluorophenylthio)-4-hydroxy-5-methyl-2-hexanone

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Reaction Conditions

Reaction Steps

9.86 Grams of methyl acetoacetate were dissolved in 15 ml of water, and 12.67 g of a 30% aqueous sodium hydroxide solution was added dropwise while cooling the mixture to not higher than 25° C. After having been stirred at 30°-35° C. for 3 hours, the mixture was adjusted to pH 7.0 with a concentrated aqueous hydrochloric acid solution. Thereafter, 0.49 g of sodium acetate and 2.42 g of tetrabutylammonium bromide were added thereto and then an additional conc. hydrochloric acid was added thereto to control the mixture to pH 6.8-6.9. Further, 27.1 g of a toluene solution containing 36.5% of 3-(4-fluorophenylthio)-2-methylpropanal were added thereto and the resulting mixture was stirred at 45°-50° C. for 8 hours. The organic layer was separated, washed with a 5% aqueous acetic acid solution and then with a saturated aqueous sodium chloride solution and then dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure to obtain a crude 6-(4-fluorophenylthio)-4-hydroxy-5-methyl-2-hexanone. A purified product was obtained by column chromatography in a yield of 40.2%. The purified product had an nD21 of 1.5396.

Provenance & Evidence