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.
通过让
1,4-二羟基-2-萘甲酸与三芳基
亚磷酸酯在选自有机酸和
无机酸的酸催化剂存在下发生反应,并从主要由低级醇和
水组成的混合溶剂中结晶,以高产率制备纯的 1,4-二羟基-2-芳基
萘甲酸酯,直到分离出
1,4-二羟基-2-萘甲酸、4-二羟基-
2-萘甲酸分离出来,并通过从主要由低级醇、
水和萃取溶剂组成的混合溶剂中结晶进一步提纯。e.,烷基取代的
芳香烃或卤素取代的脂肪族或
芳香烃。