Reactions of Quinolizines

The pyridyne-type intermediate postulated in the displacement of bromine from 2,2-dibromo-l-oxo-l,2,3,4-tetrahydroquinolizinium bromide is refered to in Section II, D. 

The facile displacement of carboxyl groups from the 1- and 3-positions of 4-quinolizone is mentioned in Section II, C and provides an easy route to the nitroquinolizones. (See Note Added in Proof, p. 314.) 

Diazonium coupling to 1-hydroxyquinolizinium bromide 21 yields a highly insoluble red product which has been assigned structure 20. The diazonium salt from l-hydroxy-3-aminoquinolizinium bromide has been coupled with alkaline j3-naphthol.21 

2-Methylquinolizinium iodide (21, X = I) has been condensed with p-dimethylaminobenzaldehyde to yield the corresponding styryl derivative (22). Reaction of the same compound with p-nitrosodi-methylaniline affords the Schiff base 23.6 The simple 2-styrylquino-lizinium bromide was reported recently by Hansen and Amstutz.14 

None of these methylquinolizinium derivatives forms an anhydro base. 

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