Acetonitrile → 4,4,4-Trifluoro-3-oxobutanenitrile

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Reaction Conditions

Reaction Steps

A solution of n-butyllithium in n-hexane (280 ml, 0.44 mole) was added to dry diisopropylamine (64 ml, 0.46 mole) dissolved in dry tetrahydrofuran (400 ml), while maintaining the mixture below 0° C. After stirring at 0° C. for 30 minutes, the mixture was cooled below -72° C. A solution of methyl trifluoroacetate (25.61 g, 0.200 mole), acetonitrile (16.42 g, 0.40 mole) in dry tetrahydrofuran (200 ml) were added dropwise, while maintaining the mixture below -72° C. and after maintaining the mixture at the same temperature for additional 45 minutes, it was warmed to room temperature over 1 hour. Ice-water (700 ml) was added to the mixture and tetrahydrofuran and n-hexane were then evaporated under reduced pressure at a bath temperature of 40° C. The residue was extracted with diethyl ether to remove neutral and basic components, adjusted to pH 1 with 36% HCl and then extracted with methylene chloride to remove by-products such as acetoacetonitrile, etc. The solution was extracted with diethyl ether. After the extract was dried with anhydrous sodium sulfate, p-toluenesulfonic acid (40 mg, 0.0002 mole) was added to the extract. The extract was distilled under the atmospheric pressure and then distilled under reduced pressure to give 26.82 g (crude yield 97.8%) of a cured product. This product was further distilled under reduced pressure to give 16.78 g (61.2%) of the title compound, b.p. 37° C./2.4 mmHg-43° C./2.5 mmHg. When the resulting compound was dissolved in d6 -acetone and its NMR was measured, the ratio of the keto form/the enol form was found to be 17/83.

Provenance & Evidence