Heterogeneous catalysis for the acetylation of benzo crown ethers

Heterogeneous catalytic acetylation of benzo-15-crown-5 was investigated using solid Lewis acids consisting of sulfated zirconia calcined at 625°C or K10 exchanged by Cu, Zn, Fe or Sn ions and treated at 250°C. The nature of the transition metal ions introduced in the mesoporous clay plays an important role in the activity of the catalysts. Sn-exchanged K10 shows the best catalytic properties and could suit for practical preparative purposes. 4′-Acetyl-benzo-15-crown-5 was produced with 90% yield under optimal conditions.