Azepines as Substrates

Catalytic hydrogenation of 2-nitromethylenehexahydro-l//-azepine (1, R = H) over palladized charcoal in acidic methanol afforded 2,5-bis(5-aminopentyl)pyrazine (2, R = H) (67%, as hydrochloride)by reduction of the nitro group, 1,2-fission, and self-condensation of the unsaturated product 145, 467 the 1-methylated substrate (1, R = Me) likewise gave 2,5-bis(5-methylaminopentyl)pyrazine (2, R = Me) but only in 10% yield.145 

Primary Syntheses from Other Heterocyclic Systems 

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