2,6-二取代苯并二噁唑的合成方法研究

Research on Synthetic Method of 2,6-Disubstituted Benzo-Bisoxazoles

文献报道合成2,6-二芳基取代苯并[1,2-d;4,5-d']二(口恶)唑有两种方法,其一是2,5-二氨基对苯醌与芳香醛缩合,然后氧化,关环;其二是2,5-二氨基对苯二酚盐酸盐与酰氯缩合关环[4]。此外Hirohashi等曾用2,5-二氨基对苯二酚盐酸盐与对氨基苯甲酸在多聚磷酸中加热,所得产物,熔点353—356℃,元素分析N含量为13.88%,计算值(16.37%),即没有得到2,6-二(对氨基苯基)苯并[1,2-d;4,5-d']二噁唑予期产物[1]。

In this paper a modified method of preparation of 2,6-disubstituted benzo-[1,2-d;4,5-d']-bisoxazoles is reported.2,5-Diamino-quinone-1,4 was reduced with stannous chloride in hydrochloric acid.The product,2,5-diamino-hydroquinone-l,4 hydrochloride was then condensed with benzoic acid and substituted benzoic acids respectively in polyphos-phoric acid.Thus,2,6-diphenyl benzo-[1,2-d;4,5-d']-bisoxazole and eleven of its substituted phenyl derivatives were prepared.