Isoquinolinium-4-olate, preparation

The preceding sections demonstrate two important general routes to six-membered heterocyclic mesomeric betaines. These are (i) deprotonation of appropriate quaternary salts and (ii) valence tautomerism of bicyclic isomers. Both approaches have been used to prepare isoquinolinium-4-olates (170) (Scheme 7). 

Indano[l,2-6]aziridin-6-ones (171), which have been prepared by three different routes,are converted to isoquinolinium-4-olates (170) by either photolysis or thermolysis. The betaines (170) have not been... 

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