Chlorination of an aryl lithium: The importance of correct selection of Cl+ source

28 February 2005

Workers at Johnson and Johnson* needed to make a 2-chloroimidazole by halogenation of the parent imidazole. A lithiation/chlorination approach worked well, but the choice of chlorinating agent was critical for success, as the table below indicates:

* N.S. Mani et al., J. Org. Chem., 2004, 69, 8115-8117.