Metalation of the biarylmethane derivative (I) by means of butyllithium, followed by iodination with N-iodosuccinimide, leads to aryl iodide (II). After desilylation of (II) using tetrabutylammonium fluoride, the resultant phenolic compound (III) is alkylated with methyl bromoacetate (IV) to produce ether (V). Palladium-catalyzed coupling between aryl iodide (V) and the phenylethynyl boronate reagent (VI) furnishes the diaryl acetylene (VII). The amino group of (VII) is oxidized to the corresponding nitro derivative employing m-chloroperbenzoic acid, and the methoxymethyl protecting group is then removed by acidic hydrolysis to afford (VIII). Finally, methyl ester hydrolysis in (VIII) in the presence of LiOH gives the target carboxylic acid.