Dimroth rearrangement

What is Dimroth rearrangement?

The Dimroth rearrangement is a reaction first described by Dimroth in 1909 that involves the base-catalyzed translocation of exo– and endo-cyclic heteroatoms on a heterocyclic ring. This reaction is commonly referred to as the Dimroth rearrangement or the Dimroth-type rearrangement, and it is also known as the Dimroth reaction in some cases.

Dimroth rearrangement - general reaction scheme - Dimroth reaction - Dimroth rearrangement - Dimroth-type rearrangement
Dimroth rearrangement

The Dimroth rearrangement occurs frequently on six-membered rings, although it can also occur on five-membered rings. Many of these rearrangements involve 1H-1,2,3-triazoles. The reaction involves a ring opening followed by a ring reclosure, and it typically results in the translocation of nitrogen as the heteroatom.