A method for the manufacture of a metal salt of a hydroxy-substituted aromatic compound comprises: contacting a hydroxy-substituted aromatic compound with a base comprising a metal cation in molten diphenyl sulfone or sulfolane to provide a mixture comprising water, diphenyl sulfone or sulfolane, and a metal salt of the hydroxy-substituted aromatic compound; and removing water from the mixture in the absence of an azeotrope solvent to provide the metal salt of the hydroxy-substituted aromatic compound that contains less than 3,000 ppm of water.