How is 5-Fluoro-2-hydroxybenzonitrile (CAS: 91407-41-9) typically synthesized?

5-Fluoro-2-hydroxybenzonitrile can be synthesized through the reaction of 2-hydroxybenzonitrile with fluorine in the presence of an appropriate catalyst, such as sulfuryl fluoride. The reaction is selective and yields a high percentage of the desired product. The process typically requires low temperatures and careful handling to avoid side reactions. The yield can be up to 90%, depending on the purity of the starting materials and reaction conditions.