Abstract
1) Nitration of isoquinoline N-oxide gives 5-nitro and 8-nitro compounds from which it was seen that the effect of N-oxide group does not extend to the benzene ring.
2) Catalytic reduction of 5-nitroisoquinoline N-oxide with palladium-carbon in acid medium gives 5-aminoisoquinoline and 5-amino-Py-tetrahydroisoquinoline while the same treatment in neutral medium gives 5-aminoisoquinoline. In the latter case, stopping the reduction after absorption of 3 moles of hydrogen gives 5-aminoisoquinoline and 5-aminoisoquinoline N-oxide from which it has been clarified that the N-oxide group in isoquinoline N-oxide possesses comparatively weak resistance against reduction but it still possesses the characteristics of the tertiary amine N-oxides.
3) Bucherer reaction of 5-aminoisoquinoline gives 5-hydroxyisoquinoline in a good yield.
