9,9-二[4-(4-羧基苯氧基)苯基]呫吨的合成

在碘化亚铜、四丁基溴化铵和磷酸钾存在下，9,9-二(4-羟基苯基)呫吨(1)和4-甲基碘苯(2)于N,N-二甲基甲酰胺溶剂中发生Ullmann偶联反应，加热回流反应24 h，以95%的产率合成了中间体--9,9-二4-(4-甲基苯氧基)苯基]呫吨(3)，继而加入催化量的N-溴代丁二酰亚胺并在光照条件下，将中间体3氧化得到一种新型芳香族二羧酸--9,9-二4-(4-羧基苯氧基)苯基]呫吨(4)，其产率为84%，二步反应总收率为79.8%。 目标化合物4经1H NMR、13C NMR、IR和元素分析测试技术确定了其结构。 该法具有原料易得，操作简单，反应条件温和，收率高等优点。

Synthesis of 9,9-Bis[4-(4-carboxyphenoxy)phenyl]xanthene

The synthetic method of a new aromatic diacid, 9,9-bis4-(4-carboxyphenoxy)phenyl]xanthene(4) was developed from the reaction of 9,9-bis(4-hydroxyphenyl)xanthene(1) with 4-methyl-1-iodobenzene(2) by means of the Ullmann coupling and oxidation reaction successively. The treatment of compound 1 with compound 2 in DMF in the presence of cuprous iodide/tetrabutylammonium bromide/potassium phosphate at reflux temperature for 24 h afforded 9,9-bis4-(4-methylphenoxy)phenyl]xanthene(3) in 95% yield. The compound 3 was then oxidized to the corresponding aromatic, 9,9-bis4-(4-carboxyphenoxy)phenyl]xanthene(4) in 84% yield directly using oxygen in the presence of a catalytic amount of N-bromosuccinimde(NBS) under photoirradiation. The new diacid 4 was obtained in an overall yield of about 79.8%(based on compound 1). The structure of the target compound was characterized by 1H NMR, 13C NMR, IR and elemental analysis. The present method has the advantage of convenient availability of starting materials, mild reaction conditions, convenient manipulation and good yield.