Isomeriza tion of simple heterocyclic compounds

Summary

• 1. The conversion of a number of oxygen-, sulfur- and ni trogen-containing heterocyclic compounds in a circulating system on a TiO₂ — A1₂O₃ catalyst at temperatures lying within the limits of 200–400° was studied.

• 2. Under the conditions used, six-membered heterocyclic compounds showed an ability to isomerize with contraction of the ring, while in the case of four-membered compounds the ring expanded. In all cases, however, these reactions are accompanied by a number of other conversions: elimination of the heteroatom, rupture of the ring and some tar formation.