The desired 2,6-diphenoxybenzoic acid can be prepared as illustrated in equation 1 ##STR4## In this method, 1,3-diphenoxybenzene is caused to react with an alkyllithium compound ZLi where Z is alkyl of 1 to 4 carbon atoms or phenyl, for example, methyllithium or butyllithium, in an ether-type solvent such as diethyl ether or tetrahydrofuran for 0.5 to 3 hours at 25°-100°, preferably at the boiling point of the solvent. The resulting intermediate, 2,6-diphenoxyphenyllithium, is added to an excess of solid carbon dioxide, or a mixture of solid carbon dioxide in ether, and the mixture is allowed to warm to room temperature to yield lithium 2,6-diphenoxybenzoate. Addition of a mineral acid, HX, such as hydrochloric acid or sulfuric acid, yields 2,6-diphenoxybenzoic acid.
