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

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Reaction Steps

3.77 Grams of methyl acetoacetate were dissolved in 5 ml of water, and 4.50 g of a 30% aqueous sodium hydroxide solution was added thereto by drops while cooling the mixture to 35° C. or less. After having been stirred at 30°-35° C. for 3 hours, the mixture was adjusted to pH 7.5 with 50% sulfuric acid. Thereafter, 0.31 g of sodium acetate and 0.81 g of tetrabutylammonium bromide were added thereto and 14.7 g of a toluene solution containing 39.8% of 3-(4-trifluoromethylphenylthio)propanal were added thereto. The mixture was stirred at 45°-50° C. for 6 hours and then at room temperature for 12 hours. After the mixture had been neutralized with a 50% sulfuric acid, the organic layer was separated, washed with a saturated aqueous sodium chloride solution and then dried over anhydrous magnesium sulfate. Removing the solvent from the layer under reduced pressure gave 6.82 g of crude 4-hydroxy- 6-(4-trifluoromethylphenylthio)-2-hexanone (purity, 92.6%). The crude product was further recrystallized from diisopropyl ether to obtain 6.04 g of a purified product. The yield of the purified product was 82.7%. It had a melting point of 73.0°-74.5° C.

Provenance & Evidence