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

Temperature

0 °C

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

ORD record

ord-c1c243bc2444450eb89a3d4f70466401

Source dataset

uspto-grants-1997_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05602118