Sodium Chloride → ((2S,3S)-3-(4-(trifluoromethyl)phenyl)oxiran-2-yl)methanol

Temperatur

-20 °C

Into a 2000 mL flame-dried flask were introduced dry powdered 4 A molecular sieves (9.0 g) and anhydrous DCM (1000 mL) under nitrogen. After cooling to −20° C., the following reagents were introduced sequentially via cannula under stirring: (diisopropyl 1-tartrate (5 g, 21 mmol); titanium tetraisopropoxide (4 mL, 14 mmol); and a 5.5 M solution of t-butylhydroperoxide (101 mL, 554 mmol). The mixture was stirred 1 hour at −20° C., and a solution of (E)-3-(4-(trifluoromethyl)phenyl)prop-2-en-1-ol (56.0 g, 277 mmol) in 150 mL DCM was added over a 30 minute period. After 8 hours of stirring at the same temperature, the reaction was quenched by addition of 24 mL of a 10% aqueous solution of NaOH saturated with NaCl (100 mL of a 10% solution were prepared by adding 10 g of NaCl to a solution of 10 g of NaOH in 95 mL water). Ether (300 mL) was added dropwise while the cold bath was maintained at −20° C. After the ether addition, the cold bath was removed, and the mixture was allowed to warm to 110° C. Stirring was maintained for an additional 15 minutes at 10° C., and anhydrous MgSO4 (24 g) and Celite (3 g) were added. After a final 30 minutes of stirring, the mixture was allowed to settle, and the upper portion was filtered through a pad of Celite. The Celite was washed with 20 mL ether. The solvents were evaporated, and tert-butyl hydroperoxide was removed by azeotropic evaporation with toluene (3×100 mL) under high vacuum. The resulting product was then chromatographed eluting with 30% EtOAc in hexane. After removing the solvent, a colorless oil was obtained as the desired product (54 g, yield=90%). 1H NMR (400 MHz, CD3OD) δ ppm 3.17 (ddd, J=4.74, 2.89, 2.15 Hz, 1H) 3.72 (dd, J=12.72, 4.70 Hz, 1H) 3.90 (dd, J=12.72, 2.93 Hz, 1H) 3.96 (d, J=1.96 Hz, 1H) 7.50 (d, J=8.02 Hz, 2H) 7.66 (d, J=8.22 Hz, 2H).

1. customInto a 2000 mL flame-dried flask
2. additionwere introduced
3. customdry
4. additionthe following reagents were introduced sequentially via cannula
5. stirringThe mixture was stirred 1 hour at −20° C.
6. stirringAfter 8 hours of stirring at the same temperature
7. customthe reaction was quenched by addition of 24 mL of a 10% aqueous solution of NaOH saturated with NaCl (100 mL of a 10% solution
8. customwere prepared
9. temperaturewas maintained at −20° C
10. customthe cold bath was removed
11. temperatureto warm to 110° C
12. stirringStirring
13. temperaturewas maintained for an additional 15 minutes at 10° C.
14. additionanhydrous MgSO4 (24 g) and Celite (3 g) were added
15. stirringAfter a final 30 minutes of stirring
16. filtrationthe upper portion was filtered through a pad of Celite
17. washThe Celite was washed with 20 mL ether
18. customThe solvents were evaporated
19. customtert-butyl hydroperoxide was removed by azeotropic evaporation with toluene (3×100 mL) under high vacuum
20. customThe resulting product was then chromatographed
21. washeluting with 30% EtOAc in hexane
22. customAfter removing the solvent

ORD-Eintrag

ord-196fefd6dbb142f3be3f3f4bc3536baa

Quelldatensatz

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07919504B2