How is 4-Fluoroisoquinoline (CAS: 394-67-2) typically synthesized?

4-Fluoroisoquinoline is typically synthesized via the reaction of isoquinoline with hydrogen fluoride (HF) in an aprotic solvent like acetonitrile. This method provides good yields and selectivity. Another route involves the fluorination of isoquinoline derivatives using fluorine gas over a suitable catalyst. Both methods require careful control of reaction conditions to achieve optimal results.