申请人:GAF Corporation
公开号:US04138571A1
公开(公告)日:1979-02-06
A feature of the present invention is the provision of imidic esters having halo and nitro substituents on the phenyl ring attached to the nitrogen atom of the imidic ester, and of a method for preparing such compounds in high yields. In accordance with the process of the present invention, it has been found that imidic esters can be prepared in high yields using available starting materials. In the process, an alkyl .beta.-alkoxy-.beta.-iminopropionate salt is reacted first with a suitable alkanol to form an orthoester intermediate in situ. Then the orthoester is converted in high yields to the corresponding imidic ester by condensation with an aniline while simultaneously removing alkanol from the reaction mixture to drive the equilibrium reaction to completion. In a preferred form of the invention, the formation of the imidic ester is carried out in a high boiling solvent whose presence enables the condensation to be carried out more effectively at a high temperatue than with alkanol alone. Particularly, the high boiling solvent mixture adds volume to the reaction mixture which enables good agitation of the reactants at a predetermined and measureable reaction temperature. Furthermore, it facilitates the simultaneous distillation of the more volatile alkanol by-product from the reaction mixture.
本发明的一个特点是提供具有卤素和硝基取代基的苯环连接到亚胺酯氮原子的亚胺酯,并提供一种制备这种化合物高产率的方法。根据本发明的方法,发现可以使用现有的起始材料高产率制备亚胺酯。在该过程中,首先将烷基β-烷氧基-β-亚胺基丙酸酯盐与适当的烷醇反应,形成原位的正酯中间体。然后,通过与苯胺缩合,同时从反应混合物中去除烷醇以将平衡反应推向完成,高产率地将正酯转化为相应的亚胺酯。在本发明的首选形式中,亚胺酯的形成是在高沸点溶剂的存在下进行的,其存在使缩合反应可以在高温下比仅使用烷醇更有效地进行。特别地,高沸点溶剂混合物为反应混合物增加了体积,从而使反应物在预定和可测量的反应温度下得到良好的搅拌。此外,它促进了更易挥发的烷醇副产物与反应混合物的同时蒸馏。