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

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Reaction Steps

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.

Provenance & Evidence