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

온도

-70 °C

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+).

1. temperatureThe reaction mixture was warmed to room temperature
2. extractionthe mixture was extracted with ethyl acetate
3. washThe ethyl acetate layer was washed with saturated brine
4. dry with materialdried (MgSO4)
5. concentrationconcentrated
6. dissolutionThe obtained residue was dissolved in methanol (30 mL)
7. additionsodium borohydride (0.27 g) was added by small portions at 0° C
8. stirringThe reaction mixture was stirred at 0° C. for 30 min
9. addition10% aqueous citric acid solution was added
10. extractionthe mixture was extracted with ethyl acetate
11. washThe ethyl acetate layer was washed with saturated brine
12. dry with materialdried (MgSO4)
13. concentrationconcentrated

ORD 기록

ord-f72d3f43451046bc97d64b33f9325a6b

출처 데이터셋

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US08318746B2