Isoquinoline is more basic than its structural isomer quinolone. It is due to the difference in the position of the nitrogen atom in these structures.
Which is more basic quinoline or isoquinoline?
While isoquinoline (pKa = 5.46) [1, 2] meets this criterion and is more basic than pyridine (pKa = 5.17) [3, 4] as expected, quinoline (pKa = 4.85) [5] on the other hand fails in this regard, despite the fact more contributing or meaningful resonance structures without disruption of benzenoid aromaticity can be written ...
Is isoquinoline basic?
Being an analog of pyridine, isoquinoline is a weak base, with a pKa of 5.14. It protonates to form salts upon treatment with strong acids, such as HCl.
