Studies on the Friedel-Crafts Reaction. XVI, Preparation of Isomeric 2-Acyl- and 3-Acyl-4-methoxy Phenols

Article abstract of DOI:10.1007/BF00905470

Acylation of 4-methoxy phenol according to Friedel and Crafts, as well as the rearrangement of its esters according to Fries lead always to 2-acyl-4-methoxy phenols or to their demethylated compounds.The unknown 3-acyl-4-methoxyphenols were prepared in two steps: First, the ester is acylated with the corresponding acyl chloride and SnCl4 in nitromethane.In the second step the resulting ketoesters are hydrolysed.This is a general method.The yields of meta-acylphenols are between 40 and 90percent.The isomeric 2-acyl-4-methoxyphenols which were partly unknown or accessible only in low yields have also been prepared for comparative spectral studies (UV, IR, NMR, MS) of ortho- and meta-acylphenols. - Keywords: Friedel-Crafts acylation; Fries rearrangement; Ketoesters; Spectral data