3-Buten-2-one,4-(4-CF3-phenyl)- → HCID 46915337, compound

Temperature

-78 °C

(E)-4-(4-(Trifluoromethyl)phenyl)but-3-en-2-one (15 g, 70 mmol) was taken up in 500 mL of toluene. (R)-(+)-2-Methyl-CBS-oxazaborolidine (1.09 M in toluene) (6.4 mL, 7.0 mmol) was added, and the mixture was chilled to −78° C. Catecholborane (13 mL, 119 mmol) was added dropwise via addition funnel in 125 mL of toluene. The mixture was stirred for 25 minutes and then gradually warmed to −45° C. and stirred for 2 hours. The yellow color taken on during the catecholborane addition faded during this time and the solution cleared. The mixture was quenched with 300 mL of water and warmed to room temperature. The mixture was partitioned in a separatory funnel. The organic portion was washed 3 times with 200 mL of 5% aq. KOH (to remove the catechol), twice with 200 mL of 10% aqueous HCl (to remove the CBS catalyst), and once with 200 mL of brine, and then dried over MgSO4. Filtration and concentration under reduced pressure afforded (S,E)-4-(4-(trifluoromethyl)phenyl)but-3-en-2-ol (15 g, 99% yield) as a yellow oil that slowly crystallized. 1H NMR (400 MHz, CDCl3) δ ppm 7.57 (d, J=8.22 Hz, 2H) 7.50-7.45 (m, 2H) 6.62 (d, J=16.04 Hz, 1H) 6.36 (dd, J=16.04, 6.06 Hz, 1H) 4.49-4.57 (m, 1H) 1.61 (d, J=4.30 Hz, 1H) 1.39 (d, J=6.46 Hz, 3H).

1. temperaturegradually warmed to −45° C.
2. stirringstirred for 2 hours
3. customThe mixture was quenched with 300 mL of water
4. temperaturewarmed to room temperature
5. customThe mixture was partitioned in a separatory funnel
6. washThe organic portion was washed 3 times with 200 mL of 5% aq. KOH (
7. customto remove the catechol), twice with 200 mL of 10% aqueous HCl (
8. customto remove the CBS catalyst), and once with 200 mL of brine
9. dry with materialdried over MgSO4
10. filtrationFiltration and concentration under reduced pressure

ORD record

ord-a3d7e8b6615d45b7ba179299d21958a5

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07919504B2