NOVEL FRIEDEL-CRAFTS REACTIONS OF SOME ARENES

Article abstract of DOI:10.1016/S0040-4020(01)90320-5

The novel secondary Friedel-Crafts acylation products of the arenes, dimethyl resorcinol, m-xylene, m-methylanisole and m-chlorotoluene using dichloroacetylchloride and anhydrous AlCl3 are described.The formation of the unexpected products has been shown to depend on the nucleophilicity of the arene and the electrophilicity of the acyl carbonyl of the initially formed acylated product.Higher molar proportion of the arene and sometimes elevated temperature are necessary for generation of the products.The reaction pathway has been shown to be influenced by the formation of the possible complex of AlCl3 and dichloroacetylchloride with the groups adjacent to the dichloroacetyl function, especially at higher temperature.Dimethylresorcinol yields the unique products 4, 5, 6, 7 and 9 and m-xylene, m-methylanisole and m-chlorotoluene furnish 10, 13 and 15 respectively.Electronic factors responsible for generation of the products and rationalisation of their formation are discussed.