[H-].[K+].C(O)(C)(C)C.[OH:8][C:9]1[CH:14]=[CH:13][C:12]([C:15]2[CH:20]=[CH:19][C:18]([C:21]#[N:22])=[CH:17][CH:16]=2)=[CH:11][CH:10]=1.O1CCCCC1.Br[CH2:30][CH2:31][CH2:32][CH2:33][CH2:34][CH2:35][OH:36].[Br-].Cl>CCCCCC.CN(C=O)C.O>[OH:36][CH2:35][CH2:34][CH2:33][CH2:32][CH2:31][CH2:30][O:8][C:9]1[CH:10]=[CH:11][C:12]([C:15]2[CH:20]=[CH:19][C:18]([C:21]#[N:22])=[CH:17][CH:16]=2)=[CH:13][CH:14]=1
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.
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