Practical synthesis of 4'-methylbiphenyl-2-carboxylic acid

Article abstract of DOI:10.1055/s-1995-3851

Treatment of 2,6-di-tert-butyl-4-methylphenyl 2-methoxybenzoate (5) with 4-methylphenylmagnesium bromide (6) in diethyl ether-benzene affords the 4'-methylbiphenyl-2-carboxylate (7) in excellent yield via an ester-assisted nucleophilic aromatic substitution (S(N)Ar) reaction. Carboxylate 7 is in turn readily and quantitatively saponified to 4'-methylbiphenyl-2-carboxylic acid (2a) via transesterification by treatment with sodium methoxide in toluene-1-methyl-2-pyrrolidone followed by aqueous hydrolysis.