Catalytic alkylation of benzofurans
The alkylation of benzofuran by isobutylene and tert-butyl alcohol in an autoclave in a flow system on ZnCl2 applied to Al2O3 was studied. The major reaction products are 2- and 3-tert-tert-butylbenzofurans, the ratio of which depends on the conditions used to carry out the reaction. The product yield depends on the acidity of the catalyst used. The predominant formation of 2-tert-butylbenzofuran in the flow system is explained by the isomerization of 3-tert-butylbenzofuran via an intermolecular mechanism.