Pyridine → 1-(Pyridin-4-yl)pyridin-1-ium chloride--hydrogen chloride (1/1/1)

HRID 495677Notes

Reaction equation

HRID 495677 reaction equation
C(O[CH2:5][CH3:6])(=O)C.S(Cl)([Cl:9])=O.[N:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1>>[ClH:9].[Cl-:9].[N:11]1[CH:16]=[CH:15][C:14]([N+:11]2[CH:6]=[CH:5][CH:14]=[CH:13][CH:12]=2)=[CH:13][CH:12]=1

Participants

4

Reactant 3

HCID 1049PyridineHCID 8857Ethyl AcetateHCID 24386Thionyl Chloride

Product 1

HCID 794611-(Pyridin-4-yl)pyridin-1-ium chloride--hydrogen chloride (1/1/1)

Conditions

Temperature
25 °C

Procedure

In one embodiment of the present invention, a process for producing 4-dimethyl amino pyridine is provided. The process comprises initially charging ethyl acetate and pyridine, one by one, under agitation, and maintaining the pot temperature at 25±5° C. Thionyl chloride is then charged gradually while maintaining the temperature below 35° C. After the addition, the reaction mass is refluxed for 4 hours at 77-80° C. After refluxing, the ethyl acetate and unreacted thionyl chloride are distilled off at atmospheric pressure. Finally, mild vacuum (400 to 600 mm Hg) is applied to ensure maximum recovery of ethyl acetate and thionyl chloride. Left over reaction mass is cooled to 40° C. Then anhydrous ethyl alcohol is added slowly while maintaining the temperature below 60° C. The resulting reaction mass is stirred well, then cooled up to 10° C. and then filtered, washed with anhydrous ethyl alcohol and dried under vacuum to get the desired salt N-[4-pyridyl] pyridinium chloride hydrochloride. Mother liquor obtained after filtration is first atmospherically distilled to recover ethyl alcohol and then hydrolysed with caustic lye solution, followed by extraction with benzene and then fractional distillation to recover benzene and pyridine, which can be recycled back into the process.

Workup

  1. customis provided
  2. temperaturewhile maintaining the temperature below 35° C
  3. additionAfter the addition
  4. temperaturethe reaction mass is refluxed for 4 hours at 77-80° C
  5. temperatureAfter refluxing
  6. distillationthe ethyl acetate and unreacted thionyl chloride are distilled off at atmospheric pressure
  7. waitLeft over reaction mass
  8. temperatureis cooled to 40° C
  9. additionThen anhydrous ethyl alcohol is added slowly
  10. temperaturewhile maintaining the temperature below 60° C
  11. customThe resulting reaction mass
  12. temperaturecooled up to 10° C.
  13. filtrationfiltered
  14. washwashed with anhydrous ethyl alcohol
  15. customdried under vacuum

Sources & evidence

ORD record
ord-eccf31ad0f69446f94745c086b297db8
Source dataset
uspto-grants-2005_09
Patent number
US06939972B2

Reaction notes

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