Diisopropylamine → 2-[[(Phenylmethyl)thio]methyl]-4,4,4-trifluorobutyric acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of lithium diisopropylamide [prepared using freshly distilled diisopropylamine (4.47 g., 44.4 mmol) and n-butyl lithium/hexane (18 mL, 45 mmol, 2.5M)] in dry tetrahydrofuran (35 mL) was added a solution of 4,4,4-trifluorobutyric acid (3.0 g., 21.0 mmol) in tetrahydrofuran (25 mL). After stirring at 0° C. for 1.5 hours, the solution was cooled to -78° C. and treated with a solution of benzyl bromomethyl thioether in tetrahydrofuran (10 mL). The solution was allowed to stir overnight as the temperature rose to ambient. Volatiles were removed in vacuo and the residue was dissolved in ethyl acetate and extracted with 1N sodium hydroxide (50 mL) and water (2×20 mL). The combined basic extracts were acidified with concentrated hydrochloric acid (8 mL) and extracted with ethyl acetate (2×100 mL). The organic extracts were washed with water and brine, combined, dried (MgSO4), and concentrated in vacuo to give 3.82 g. of an oil. Flash chromatography on 350 mL of silica gel and elution with ethyl acetate:hexanes:acetic acid, 50:100:1 gave 1.36 g. of the title A product, TLC Rf =0.38 (ethyl acetate:hexanes:acetic acid, 50:50:1).

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