Acylation of aromatic ethers over solid acid catalysts: scope of the reaction with more complex acylating agents.
Acylation of anisole with 2-phenylbutanoic acid derivatives, over zeolite catalysts, gives the corresponding 4-acyl derivatives with high regioselectivity. In an analogous way, 2,3-dihydrobenzofuran reacts with acid anhydrides or chlorides in the presence of catalytic quantities of zeolites to give the corresponding 5-acyl-2,3-dihydrobenzofurans. The zeolite can be recovered, regenerated and used again to give almost the same yield as with fresh zeolite. The reaction has been applied to the synthesis of ethyl (2,3-dihydrobenzofuran-5-yl)glyoxylate.
Smith
Keith
K
Centre for Clean Chemistry, Department of Chemistry, University of Wales Swansea, Singleton Park, Swansea, UK SA2 8PP.
El-Hiti
Gamal A
GA
Jayne
Anthony J
AJ
Butters
Michael
M