Ethyl 2-methyl-4,4,4-trifluoroacetoacetate → Ethyl 3-hydroxy-2-methyl-4,4,4-trifluorobutyrate

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Reaction Steps

To a solution of ethyl 3-keto-2-methyl-4,4,4-trifluorobutanoate (20.1 g, 0.10 moles) in 250 ml of absolute ethanol, cooled in an ice bath, was added sodium borohydride (1.0 g, 0.25 moles) in portions with stirring. The cooling bath was removed and the reaction stirred at room temperature for 30 minutes. Acetone (5 ml) was added to quench any remaining sodium borohydride and the solvents removed by distillation at atmospheric pressure using a Vigreaux column. The residue was diluted with 200 ml of methylene chloride and poured into a separatory funnel containing 75 ml of a 1:1:1 mixture of saturated ammonium chloride:brine:water. The layers were separated and the aqueous phase extracted with methylene chloride (3×25 ml). The combined organic phase and methylene chloride extracts were dried over magnesium sulfate, filtered and distilled at atmospheric pressure to remove the solvents. The residue was then distilled at reduced pressure (20 mmHg) using a Vigreaux column to give ethyl 3-hydroxy-2-methyl-4,4,4-trifluorobutanoate, bp 78°-84° C., 20 mmHg.

Provenance & Evidence