反应详情

In the same manner as in Example 9, 21.0 g of 4-(p-fluorophenyl)-1,1-dichloro-1-silacyclohexane was obtained from 4-(p-fluorophenyl)-1,1-diphenyl-1-silacyclohexane obtained in Preparatory Example 5. A mixture of 50.0 g of methanol and 30 g of triethylamine was added to the solution obtained above, followed by agitation under reflux for 1 hour. The resultant solution was concentrated, to which 200 ml of hexane was added thereby permitting secondarily produced hydrochloride to be precipitated. The precipitate was removed by filtration and the resulting filtrate was concentrated to obtain a mixture of 4-(p-fluorophenyl)-1,1-dimethoxy-1-silacyclohexane and acetophenone. The mixture was subjected to distillation under reduced pressure to remove the acetophenone therefrom. The resultant residue was dissolved in 100 ml of THF and added to a solution of 10.0 g of lithium aluminium hydride in 100 ml of THF. The reaction mixture was agitated under reflux for 1 hour, which was poured into 200 ml of 5% hydrochloric acid and extracted with ethyl acetate. The ethyl acetate solution was washed with brine, dried and concentrated by a usual manner, followed by purification through silica gel chromatography to obtain 14.7 g of 4-(p-fluorophenyl)-1-silacyclohexane. Subsequently, 14.0 g of 4-(p-fluorophenyl)-1-silacyclohexane was added to 100 ml of toluene, into which chlorine gas was blown to obtain 4-(p-fluorophenyl)-1-chloro-1-silacyclohexane. This solution was dropped in 100 ml of a THF solution of 1 mole/liter of trans-2-(4-n-propylcyclohexyl)ethylmagnesium bromide at room temperature. The reaction mixture was charged into 200 ml of 5% hydrochloric acid and extracted with ethyl acetate. The ethyl acetate solution was washed with brine, dried and concentrated, followed by purification through silica gel chromatography to obtain 20.8 g of the intended product. The thus obtained product exhibited nematic liquid crystal properties at a temperature between 49.1° C. and 62.9° C. and was found to be very useful as a liquid crystal substance.

1. customobtained in Preparatory Example 5
2. additionwas added to the solution
3. customobtained above,
4. temperatureunder reflux for 1 hour
5. concentrationThe resultant solution was concentrated, to which 200 ml of hexane
6. additionwas added
7. customto be precipitated
8. customThe precipitate was removed by filtration
9. concentrationthe resulting filtrate was concentrated
10. customto obtain
11. distillationThe mixture was subjected to distillation under reduced pressure
12. customto remove the acetophenone
13. dissolutionThe resultant residue was dissolved in 100 ml of THF
14. additionadded to a solution of 10.0 g of lithium aluminium hydride in 100 ml of THF
15. temperatureunder reflux for 1 hour
16. additionwhich was poured into 200 ml of 5% hydrochloric acid
17. extractionextracted with ethyl acetate
18. washThe ethyl acetate solution was washed with brine
19. customdried
20. concentrationconcentrated by a usual manner
21. customfollowed by purification through silica gel chromatography