Citric Acid → 1-[2-(1,3-Dioxolan-2-yl)-1,3-thiazol-5-yl]-2,2,2-trifluoroethanol

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-(1,3-dioxolan-2-yl)-1,3-thiazole (2.00 g) in tetrahydrofuran (50 mL) was slowly added a 1.6M n-butyllithium hexane solution (8.7 mL) at −70° C. under a nitrogen atmosphere. The reaction mixture was stirred at −70° C. for 30 min, and ethyl trifluoroacetate (5.4 g) was added. The reaction mixture was warmed to room temperature, 10% aqueous citric acid solution was added, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried (MgSO4) and concentrated. The obtained residue was dissolved in methanol (30 mL), and sodium borohydride (0.27 g) was added by small portions at 0° C. The reaction mixture was stirred at 0° C. for 30 min, 10% aqueous citric acid solution was added, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried (MgSO4) and concentrated. The obtained residue was subjected to silica gel column chromatography, and the title compound (2.56 g, yield 79%) was obtained as a yellow oil from a fraction eluted with ethyl acetate-hexane (1:1, volume ratio). MS: 256 (MH+).

Provenance & Evidence