Hydrochloric Acid → 4-Hydroxy-6-(4-trifluoromethylphenylthio)2-hexanone

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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 were added thereto by drops while cooling the mixture to 25° C. or less. 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, and then an additional concentrated aqueous hydrochloric acid solution was added to the mixture so that the mixture was adjusted to pH 6.8. Further, 28.9 g of a toluene solution containing 40.5% of 3-(4-trifluoromethylphenylthio)propanal were added. The mixture was stirred at 45°-50° C. for 10 hours while maintaining the pH of the mixture at 7.2-7.3 with 2N hydrochloric acid. The organic layer was separated, washed with a 5% aqueous acetic solution and then with a saturated aqueous sodium chloride solution. Then the layer was dried over anhydrous magnesium sulfate. Removing the solvent from the layer under reduced pressure gave 16.1 g of crude 4-hydroxy-6-(4-trifluoromethylphenylthio)-2-hexanone (purity: 88.6%, yield: 97.8%).

Provenance & Evidence