2,4-Difluorobenzaldehyde → 2,4-Difluoro-alpha-2-propenylbenzenemethanol

Temperatur

0 °C

Under anhydrous condition at 0° C., a minute of 18.0 g of freshly distilled 2,4-difluorobenzaldehyde and 120 ml of diethyl ether is treated, dropwise, with 139 ml of 1M allyl magnesium bromide. The reaction is stirred at 0° C. for 1 hour then slowly allowed to warm to room temperature. After 5 hours, thin layer chromatography indicates complete reaction. The mixture is cooled to 0° C. and quenched by the dropwise addition of 100 ml of ice cold saturated ammonium chloride. Two hundred ml of diethyl ether is added and the layers are separated. The aqueous layer is extracted with diethyl ether. The organic layers are combined, washed twice with saturated sodium chloride, dried , filtered and concentrated in vacuo. The residue is purified by Kugelrohr distillation (100° C.) to give 19.9 g of the desired product as a mixture of isomers.

1. temperatureto warm to room temperature
2. waitAfter 5 hours
3. customreaction
4. temperatureThe mixture is cooled to 0° C.
5. customquenched by the dropwise addition of 100 ml of ice cold saturated ammonium chloride
6. additionTwo hundred ml of diethyl ether is added
7. customthe layers are separated
8. extractionThe aqueous layer is extracted with diethyl ether
9. washwashed twice with saturated sodium chloride
10. customdried
11. filtrationfiltered
12. concentrationconcentrated in vacuo
13. distillationThe residue is purified by Kugelrohr distillation (100° C.)

ORD-Eintrag

ord-bb7c077f760a453f8a9bcae6ad83fd3c

Quelldatensatz

uspto-grants-1997_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05623081