The Reactions of Diazomethane with Heterocyclic Compounds

Publisher Summary Diazomethane undergoes numerous reactions. In the heterocyclic series, its reactions can be divided into the following types: (1) methylations––lactams, thiolactams, amino compounds, and enols; and (2) other reactions. This chapter presents the reactions of diazomethane with heterocyclic compounds. The most important applications of diazomethane depend on its ability to replace a mobile hydrogen atom by a methyl group. Diazomethane occupies a special place in comparison with other methylation agents because only strongly acidic protons are replaced. The basic properties of diazomethanes have been utilized in the liberation of heterocyclic bases from their salts. Methylation of lactams with diazomethane, the infrared (IR) spectra of lactams, and the reaction of lactams with diazomethane are tabulated in the chapter and the methylation of thiolactams, heterocyclic amino compounds, and heterocyclic enols is discussed. Some other reactions of diazomethane with heterocycles—namely, C=C double bonds and C=X double bonds—are presented as well.