Iodination and Metal Halogen Exchange of Aromatic Compounds: An Improved Preparation of a Key Oxazolidinone Antibiotic Intermediate

A new method for the preparation of a key intermediate for oxazolidinone antibiotic analogues is discussed. We have found that iodine−magnesium exchange can be used to prepare a dianion if a fluorine is present ortho to the aryl anion and that exchange takes place on iodoanisoles. In addition, we report an improved method for iodination of aromatics using N-chlorosuccinimide/hydriodic acid and potassium iodide. By using these conditions, reactions are faster and higher-yielding than using either N-iodosuccinimide or iodine monochloride.