Three-component access to pyrroles promoted by the CAN-silver nitrate system under high-speed vibration milling conditions: a generalization of the Hantzsch pyrrole synthesis

A sequential multicomponent process involving the high-speed vibration milling of ketones with N-iodosuccinimide and p-toluenesulfonic acid, followed by addition of a mixture of primary amines, beta-dicarbonyl compounds, cerium(IV) ammonium nitrate and silver nitrate afforded polysubstituted, functionalized pyrroles. This one-pot, solid-state process can be considered as the coupling of an alpha-iodoketone preparation with a general version of the classical Hantzsch pyrrole synthesis.