Pyridine → 2,6-Di-tert-butyl-4-[(pyrazin-2-yl)imino]cyclohexa-2,5-dien-1-one

HRID 345762Notes

Reaction equation

HRID 345762 reaction equation
N1C=CC=CC=1.[C:7]([C:11]1[C:12](=[O:22])[C:13]([C:18]([CH3:21])([CH3:20])[CH3:19])=[CH:14][C:15](=O)[CH:16]=1)([CH3:10])([CH3:9])[CH3:8].[NH2:23][C:24]1[CH:29]=[N:28][CH:27]=[CH:26][N:25]=1>ClC(Cl)C.[Ti](Cl)(Cl)(Cl)Cl>[C:7]([C:11]1[C:12](=[O:22])[C:13]([C:18]([CH3:21])([CH3:20])[CH3:19])=[CH:14][C:15](=[N:23][C:24]2[CH:29]=[N:28][CH:27]=[CH:26][N:25]=2)[CH:16]=1)([CH3:10])([CH3:9])[CH3:8]

Participants

6

Reactant 3

HCID 1049PyridineHCID 128672,6-Di-t-butyl-p-benzoquinoneHCID 78747Aminopyrazine

Product 1

HCID 143736662,6-Di-tert-butyl-4-[(pyrazin-2-yl)imino]cyclohexa-2,5-dien-1-oneYield 46.4%

Reagents, catalysts & solvents 2

HCID 24193Titanium TetrachlorideCatalystHCID 63651,1-DichloroethaneSolvent

Procedure

A 97.1 ml quantity of pyridine was dissolved in 944 ml of dichloroethane, and 32.9 ml of titanium tetrachloride was added thereto. The resulting mixture was refluxed with heating for 15 minutes. To the mixture were then added 132.2 g of 2,6-di-tert-butyl-1,4-benzoquinone and 57.1 g of aminopyrazine, and the mixture was refluxed with heating for 42 hours. The reaction mixture was cooled to room temperature and filtered through a Celite pad and the insoluble materials were washed there with dichloromethane. The filtrate was concentrated, and the resulting crude product was purified by silica gel column chromatography (eluent: diethyl ether-hexane=3:7), giving 82.8 g of Compound 1a.

Workup

  1. temperatureThe resulting mixture was refluxed
  2. temperaturewith heating for 15 minutes
  3. temperaturethe mixture was refluxed
  4. temperaturewith heating for 42 hours
  5. filtrationfiltered through a Celite pad
  6. washthe insoluble materials were washed there with dichloromethane
  7. concentrationThe filtrate was concentrated
  8. customthe resulting crude product was purified by silica gel column chromatography (eluent: diethyl ether-hexane=3:7)

Sources & evidence

ORD record
ord-aebe2d2b4a1e45d49b6a2f85040e0619
Source dataset
uspto-grants-1991_10
Patent number
US05059598

Reaction notes

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