反応 #361334

反応方程式

tetrahydropyran

6-bromohexanol

4'-Hydroxy-4-cyanobiphenyl

bromide

hydrochloric acid

t-butyl alcohol

potassium hydride

→

4'-(6-hydroxyhexyloxy)-4-cyanobiphenyl

溶媒

water

DMF

hexane

反応条件

後処理

1. 1
   その他to give a deep yellow solution
2. 2
   workup.WAITAfter 2 h
3. 3
   workup.STIRRINGthe reaction mixture was stirred for 1 h
4. 4
   抽出extracted with ether-dichloromethane (4:1)
5. 5
   その他to be removed by filtration through glass fiber
6. 6
   その他to obtain good
7. 7
   その他separation of phases
8. 8
   洗浄The extracts were washed with water
9. 9
   乾燥dried (MgSO4)
10. 10
    濃縮concentrated to a solid (7.7 g)
11. 11
    workup.STIRRINGThe solid was stirred with tetrahydrofuran-2.5 N hydrochloric acid (4:1, 50 mL) overnight at room temperature
12. 12
    温度heated
13. 13
    温度to reflux for 2.0 h
14. 14
    その他The ethanol was removed
15. 15
    抽出the aqueous phase was extracted with ether-dichloromethane (4:1)
16. 16
    洗浄The extracts were washed with water
17. 17
    乾燥dried (MgSO4)
18. 18
    濃縮concentrated to a solid
19. 19
    その他that was recrystallized from ethanol-ether

実験手順

At room temperature, potassium hydride (2.5 g, 35 wt % oil dispersion, 0.88 g KH, 22 mmol) was washed twice with hexane and suspended in DMF (30 mL), followed by addition of t-butyl alcohol (2.1 mL, 1.63 g, 22 mmol). 4'-Hydroxy-4-cyanobiphenyl (3.9 g, 20 mmol) was added as a solid all at once to give a deep yellow solution. The mixture was stirred 5 min at room temperature and the tetrahydropyran of 6-bromohexanol (5.8 g, 22 mmol) was added all at once with a mild exotherm. After 2 h, more bromide (1.0 g) was added and the reaction mixture was stirred for 1 h. The mixture was diluted with water, acidified with 5 N hydrochloric acid and extracted with ether-dichloromethane (4:1). An insoluble white solid had to be removed by filtration through glass fiber to obtain good separation of phases. The extracts were washed with water, dried (MgSO4) and concentrated to a solid (7.7 g). The solid was stirred with tetrahydrofuran-2.5 N hydrochloric acid (4:1, 50 mL) overnight at room temperature and then heated to reflux for 2.0 h. The ethanol was removed and the aqueous phase was extracted with ether-dichloromethane (4:1). The extracts were washed with water, dried (MgSO4) and concentrated to a solid that was recrystallized from ethanol-ether to give 4'-(6-hydroxyhexyloxy)-4-cyanobiphenyl: (3.25 g, 55%): mp 87-89° C., nematic phase 89-106° C.; 1H NMR (CDCl3) 7.63(s, 4H), 7.46 and 6.90(2d, 4H), 3.97(t, 2H), 3.62(t, 2H), 1.9-1.3(m, 8H); IR (KBr) 3300, 2225, 1601, 1580, 1525 cm-1.

出典