E-methyl 6,6,6-trifluoro-5-hydroxy-5-(trifluoromethyl)hex-2-enoate → Methyl 6,6,6-trifluoro-5-hydroxy-5-(trifluoromethyl)hexanoate

To a 330 mL thick-walled glass hydrogenation vessel was added 37.7 g E-methyl 6,6,6-trifluoro-5-hydroxy-5-(trifluoromethyl)hex-2-enoate (I) (141 mmol), 0.5 g palladium-on-carbon (5 wt % Pd), and 150 mL ethyl acetate. The reaction vessel was attached to a Parr hydrogenation apparatus and the reaction solution degassed via three successive pump-backfill cycles with nitrogen. The reaction vessel was pressurized to 40 psi with hydrogen and shaken at room temperature for 20 hours, after which the pressure had fallen to 34 psi. The excess hydrogen was removed via three successive pump-backfill cycles with nitrogen and the palladium catalyst removed via filtration through 1.0 micron glass fiber and 0.2 micron PTFE filters. The solvent was removed in vacuo and the crude reaction mixture distilled under vacuum (6 Torr, 64-74° C.) to afford 34.4 g (91%) of methyl 6,6,6-trifluoro-5-hydroxy-5-(trifluoromethyl)hexanoate (II) as a colorless liquid.

1. customthe reaction solution degassed via three successive pump-backfill cycles with nitrogen
2. customThe excess hydrogen was removed via three successive pump-backfill cycles with nitrogen
3. customthe palladium catalyst removed via filtration through 1.0 micron glass fiber and 0.2 micron PTFE
4. customThe solvent was removed in vacuo
5. customthe crude reaction mixture
6. distillationdistilled under vacuum (6 Torr, 64-74° C.)

ORD-Eintrag

ord-34836a414c9c4e2c83e08b6b670887c8

Quelldatensatz

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07781157B2