Acetic Anhydride → HCID 13651195, compound

HRID 235781Notes

Reaction equation

HRID 235781 reaction equation
[OH:1][C:2]1[CH:3]=[N:4][C:5]([CH3:8])=[CH:6][CH:7]=1.[C:9]([C:11]1[CH:18]=[CH:17][C:14]([CH:15]=O)=[CH:13][CH:12]=1)#[N:10].C(OC(=O)C)(=O)C>>[OH:1][C:2]1[CH:3]=[N:4][C:5]([CH2:8][CH2:15][C:14]2[CH:17]=[CH:18][C:11]([C:9]#[N:10])=[CH:12][CH:13]=2)=[CH:6][CH:7]=1

Participants

4

Reactant 3

HCID 7918Acetic AnhydrideHCID 142752-Methyl-5-hydroxypyridineHCID 660424-Cyanobenzaldehyde

Product 1

HCID 13651195HCID 13651195, compoundYield 20.8%

Procedure

A mixed solution of 3-hydroxy-6-methylpyridine (3.3 g, 0.03 mol), 4-cyanobenzaldehyde (3.9 g, 0.03 mol) and acetic anhydride (6.1 g, 0.06 mol) was heated under reflux for 25 hours, followed by cooling the reaction mixture, thereafter adding toluene (30 cc), separating the resulting solids by filtration, washing the solids with toluene till the toluene filtrate became colorless, adding methanol (20 cc) and conc. hydrochloric acid (20 cc) to the solids, heating the mixture for 3 hours, cooling, neutralizing with aqueous ammonia, filtering, dissolving the resulting precipitate in ethanol (50 cc), adding Pd-C catalyst (0.3 g), 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 a mixed solvent of methanol/water (2:1) to obtain 3-hydroxy-6-[β-(4-cyanophenyl)ethyl]pyridine (1.4 g). To this compound were then added toluene (50 cc) and pyridine (3 cc), followed by adding 4-pentoxybenzoyl chloride (1.4 g) to the resulting solution, 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 ethanol to obtain the objective 6-[β-4-(cyanopheny)ethyl]-3-(4-pentyloxybenzoyl)pyridine (0.7 g) having as its phase transition points, a crystalline-nematic point (C-N point) of 107.8°-108.7° C. and a nematic-clearing point (N-I point) of 156.5°-156.8° C.

Workup

  1. temperatureunder reflux for 25 hours
  2. temperatureby cooling the reaction mixture
  3. customadding toluene (30 cc), separating the resulting solids
  4. filtrationby filtration
  5. washwashing the solids with toluene till the toluene filtrate
  6. additionadding methanol (20 cc) and conc. hydrochloric acid (20 cc) to the solids
  7. temperatureheating the mixture for 3 hours
  8. temperaturecooling, neutralizing with aqueous ammonia
  9. filtrationfiltering
  10. dissolutiondissolving the resulting precipitate in ethanol (50 cc)
  11. additionadding Pd-C catalyst (0.3 g)
  12. customat room temperature
  13. customAfter completion of the reaction
  14. filtrationthe catalyst was filtered off
  15. distillationby distilling off the solvent under reduced pressure
  16. customrecrystallizing the remaining solids from a mixed solvent of methanol/water (2:1)

Sources & evidence

ORD record
ord-ab9a006361da43679f15912260178d19
Source dataset
uspto-grants-1987_02
Patent number
US04642199

Reaction notes

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