反应详情

A mixed solution of 3-pentyloxy-6-methylpyridine (3.6 g, 0.02 mol), 4-hydroxybenzaldehyde (2.4 g, 0.02 mol) and acetic anhydride (4.1 g, 0.04 mol) was heated under reflux for 30 hours, followed by cooling the solution, adding a mixed solution of methanol (30 cc) and conc. hydrochloric acid (30 cc), heating the mixture for 3 hours, cooling, neutralizing with aqueous ammonia, extracting with toluene (50 cc), separating the resulting toluene layer, washing with water, and distilling off the toluene under reduced pressure to obtain a concentrate (3.7 g). To this concentrate were added toluene (50 cc) and pyridine (3 cc), followed by dropwise adding to the resulting solution, trans-4-pentylcyclohexanecarboxylic acid chloride (2.2 g, 0.01 mol), allowing the mixture to stand overnight, washing with water, then with 2N-hydrochloric acid, further with 2N-NaOH aqueous solution and finally with water till the washing water became neutral, distilling off toluene under reduced pressure, and recrystallizing the remaining solids from heptane to obtain 6-[4-(trans-4-pentylcyclohexylcarbonyloxy)styryl]-3-pentyloxypyridine (0.8 g), which was then dissolved in toluene (50 cc), followed by adding Pd-C (0.2 g) to the solution, and subjecting the mixture to catalytic reduction at room temperature and the atmospheric pressure. After completion of the reaction, the catalyst was filtered off, followed by distilling off the solvent under reduced pressure and recrystallizing the remaining solids from heptane to obtain the objective 6-[4-(trans-4-pentylcyclohexylcarbonyloxy)phenethyl]-3-pentyloxypyridine (0.4 g), having as phase transition points, a crystalline-smectic point of 67.2°-68.1° C., a smectic A-nematic point of 101.0°-102.0° C. and a N-I point of 131.1°-131.5° C.

1. temperatureunder reflux for 30 hours
2. temperatureby cooling the solution
3. temperatureheating the mixture for 3 hours
4. extractionextracting with toluene (50 cc)
5. customseparating the resulting toluene layer
6. washwashing with water
7. distillationdistilling off the toluene under reduced pressure
8. customto obtain
9. concentrationa concentrate (3.7 g)
10. additionTo this concentrate were added toluene (50 cc) and pyridine (3 cc)
11. washwashing with water
12. distillationdistilling off toluene under reduced pressure
13. customrecrystallizing the remaining solids from heptane