A Practical Synthesis of Highly Hindered Biphenyl-2-carboxylates via Nucleophilic Aromatic Substitution of <i>tert</i>-Butyl 2-Methoxybenzoates with Aryl Grignard Reagent
and protecting activities for peripheral and central nervous system degeneration. A synthesis of the biphenyl-2-carboxylic acid derivative, which is the key intermediate of OPC-34165, is described employing the SNAr reaction of tert-butyl 2-methoxybenzoate with aryl Grignardreagent in refluxing THF−toluene.