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. washwashed twice with saturated sodium chloride
11. customdried
12. filtrationfiltered
13. concentrationconcentrated in vacuo
14. distillationThe residue is purified by Kugelrohr distillation (100° C.)

ORD record

ord-7b940c93c1a84ef8869e8c4e3d38f918

Source dataset

uspto-grants-1998_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05750735