C_2对称双噁唑啉的新合成方法

New approach for synthesis of C_2-symmetric bis(oxazoline)

在脱水剂PCl3的存在下,噻吩-2,5-二甲酸与乙醇胺反应直接生成噻吩-2,5-双噁唑啉及未环化产物1和2。副产物1和2碱性关环生成噻吩-2,5-双噁唑啉,总收率达63%。此方法的优点是合成路线短,操作简单。

The reaction of 2,5-thiophene dicarboxylic acid with ethanolamine in the presence of dehydrating agent PCl3 gave 2,5- thiophene bis（oxazoline） and the non-cyclizing product of 1 and 2. The non-cyclizing product can be converted to 2,5-thiophene bis（oxazollne） in an alkaline environment, with its total yield reaching 63 % . The advantages of this method over previously reported ones are the shorter route and convenient operating procedure.