5-氨基-2-(4-氨基苯)苯并噁唑合成研究

Syntheses of 5-Amino-2-(4-aminophenyl)benzoxazole

以邻氨基对硝基苯酚和对硝基苯甲酰氯为原料进行酰胺化反应,再用多聚磷酸进行环化反应,得到中间体5-硝基-2-(4-硝基苯)苯并噁唑(NNB);中间体在77～80℃,压力为2.0～2.5MPa,Raney-Ni作催化剂条件下高压催化加氢合成了5-氨基-2-(4-氨基苯)苯并噁唑,纯度为99.8%,总收率为81.1%。通过熔点、MS、元素分析对产品进行了结构表征。

The intermediate 5-nitro-2-（4-nitrophenyl）benzoxazole （NNB） was synthesized from 2-amino-4- nitrophenol and 4-nitrobenzoyl chloride through amidation reaction and cyclization using polyphosphoric acid （PPA）, and was hydrogenated to give the intermediate 5-amino-2-（4-aminophenyl）benzoxazole （ABO） at 77-80℃ under 2.0-2.5 MPa in the presence of catalyst Raney-Ni. The total yield of ABO was 81.10%, the purity was 99.75%. Structures of the target product was characterized with m.p. determination, MS and elementary analysis.