反应详情

4-Acetyl-2-fluorobiphenyl (150 gram), 99% hydrazine hydrate (150 ml), potassium hydroxide (105 gram), digol (900 ml) and xylene (150 ml) were heated at 125° C. for 16 hours with stirring, after which the xylene and excess hydrazine hydrate were distilled until the internal temperature reached 165° C. The mixture was heated under reflux for three hours, cooled to 40° and poured into 5 liters of water. The product was extracted with petroleum ether (bp 60°-80°, 2×2 liter), the extract washed with water, dried over anhydrous sodium sulphate and evaporated. 4-Ethyl-2-fluorobiphenyl (95 gram, 68% theory) formed a colourless oil bp 130°/0.8 mm. Other 4-Alkyl-2-fluorobiphenyls were prepared by reaction of 2-fluoro-4-biphenylyl magnesium bromides with n-alkyl bromides and were colourless oils with the following properties listed in Table 5.

1. distillationafter which the xylene and excess hydrazine hydrate were distilled until the internal temperature
2. customreached 165° C
3. temperatureThe mixture was heated
4. temperatureunder reflux for three hours
5. temperaturecooled to 40°
6. additionpoured into 5 liters of water
7. extractionThe product was extracted with petroleum ether (bp 60°-80°, 2×2 liter)
8. washthe extract washed with water
9. dry with materialdried over anhydrous sodium sulphate
10. customevaporated