تفاعل #361332

معادلة التفاعل

4'-hydroxy-4-cyanobiphenyl

potassium carbonate

1,6-dibromohexane

→

4'-(6-bromohexyloxy)-4-cyanobiphenyl

المردود 67.0%

المذيبات

acetone

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةwas heated
2. 2
   درجة الحرارةto reflux for 6 hours ("h") under a nitrogen atmosphere
3. 3
   تركيزThe acetone was concentrated
4. 4
   workup.DISSOLUTIONthe residue dissolved in ether-dichloromethane (4:1, 400 mL)
5. 5
   ترشيحThe solution was filtered through glass fiber
6. 6
   غسيلThe filtrate was washed with water and brine
7. 7
   تجفيفdried over magnesium sulfate
8. 8
   تركيزconcentrated
9. 9
   أخرىExcess 1,6-dibromohexane was removed by Kugelrohr distillation up to 75° C. at 0.1 mm Hg
10. 10
    أخرىpot was recrystallized from ethanol (100 mL)
11. 11
    ترشيحfiltered while hot, and
12. 12
    درجة الحرارةcooled in the freezer

الإجراء التجريبي

A mixture of 4'-hydroxy-4-cyanobiphenyl (7.8 g, 40 mmol), potassium carbonate (8.3 g, 60 mmol), 1,6-dibromohexane (29.8 g, 120 mmol), and acetone (80 milliliters ("mL")) was heated to reflux for 6 hours ("h") under a nitrogen atmosphere. The acetone was concentrated and the residue dissolved in ether-dichloromethane (4:1, 400 mL). The solution was filtered through glass fiber. The filtrate was washed with water and brine, dried over magnesium sulfate, and concentrated. Excess 1,6-dibromohexane was removed by Kugelrohr distillation up to 75° C. at 0.1 mm Hg. The material remaining in the pot was recrystallized from ethanol (100 mL), filtered while hot, and cooled in the freezer to give crystals of the 4'-(6-bromohexyloxy)-4-cyanobiphenyl (9.6 g, 67%): melting point ("mp") 65.5-66° C., nematic mesophase at 63° C. in cooling; NMR (CDCl3) 7.55(s, 4H), 7.49(d, 2H), 6.82(d, 2H), 3.91(t, 2H), 2.0-1.3(m, 8H); IR (CH2Cl2) 2222, 1602 cm-1.

المصدر