反应详情

A solution of 4-bromo-2-fluorobiphenyl (2.51g;0.01 mole) in dry tetrahydrofuran (15ml) was aded dropwise, with stirring, to magnesium turnings (0.25g;0.0103g. atom) under a nitrogen atomosphere. When the addition was complete, the mixture was stirred and boiled under reflux for 30 minutes. The mixture was then cooled and a suspension of sodium 2-bromopropionate (1.75g;0.01 mole) in dry tetrahydrofuran (20ml) was added. Frothing occurred and when this had subsided the mixture was boiled under reflux with stirring, for one hour. The mixture was then cooled in an ice-bath and water (15ml) was added, followed by sulphuric acid (20%;5ml). The mixture was stirred for 10-15 minutes, and extracted with ether. The extract was washed with water and then extracted with aqueous potassium carbonate (1N). This extract was washed with ether and then added to a mixture of concentrated hydrochloric acid (10ml) and water (20ml). The mixture was cooled overnight and the precipitate filtered, washed with water and dried in vacuo to give 2 -(2-fluoro-4-biphenylyl)propionic acid.

1. additionWhen the addition
2. temperatureunder reflux for 30 minutes
3. temperatureThe mixture was then cooled
4. additionwas added
5. temperatureunder reflux
6. stirringwith stirring, for one hour
7. temperatureThe mixture was then cooled in an ice-bath
8. stirringThe mixture was stirred for 10-15 minutes
9. extractionextracted with ether
10. washThe extract was washed with water
11. extractionextracted with aqueous potassium carbonate (1N)
12. washThis extract was washed with ether
13. additionadded to a mixture of concentrated hydrochloric acid (10ml) and water (20ml)
14. temperatureThe mixture was cooled overnight
15. filtrationthe precipitate filtered
16. washwashed with water
17. customdried in vacuo