Novel Procedure for the Coupling of Sterically Hindered Electron-Deficient Anilines to the 6-Position of the Purine Core
摘要:
Sterically hindered electron-deficient anilines are coupled to the 6-position of the purine core only when activated as their corresponding TFA-amide. The free anilines did not react under all conditions tested. After aqueous work-up, the TFA-group is lost.This procedure provides a new tool in the construction of purines functionalized with a sterically hindered electron-deficient aniline in the 6-position.
An optimized procedure is given for the synthesis of novel 3-(arylamino)-1,2,4-triazin-5-one building blocks from commercially available material. By employing these building blocks, a practical protocol is described for the functionalization of the 5-position of the triazine core with anilines orphenols.