Process for producing 1,4-dihydroxy-2-arylnaphthoate

摘要

Pure 1,4-dihydroxy-2-arylnaphthoate is prepared in high yield by allowing 1,4-dihydroxy-2-naphthoic acid to react with triarylphosphite in the presence of an acid catalyst selected from organic and inorganic acids and crystallizing from a mixed solvent consisting essentially of lower alcohols and water until 1,4-dihydroxy-2-naphthoic acid is isolated and is further purified by crystallization from a mixed solvent consisting essencially of lower alcohols, water and extraction solvent, i.e., alkyl-substituted aromatic hydrocarbons or halogen-substituted aliphatic or aromatic hydrocarbons.