Trifluoroethoxy group as a leaving group for regioselective sequential substitution reactions of 5-trifluoromethylpyrimidine derivative with heteroatom nucleophiles
作者:Takumi Kagawa、Daiki Shigehiro、Kosuke Kawada
DOI:10.1016/j.jfluchem.2015.07.016
日期:2015.11
Highly regioselective substitution reaction of 2,4-bis(2,2,2-trifluoroethoxy)-5-(trifluoromethyl)pyrimidine (TFEFP) with aniline derivatives smoothly proceeded firstly at the 2-postion. For the subsequent nucleophilic substitution at the 4-position with alkoxides, trifluoroethoxy group at the 4-position serves as a practically efficient leavinggroup.
Halogenated nucleoside derivatives were trifluoromethylated using a solution of a trifluoromethyl–coppercomplex, which was prepared by shaking trifluoromethyl iodide and copper powder in hexamethylphosphoric triamide and filtering off the excess of copper powder. The following trifluoromethylated nucleosides were obtained in moderate to good yields: 5-trifluoromethyl-uridine, -deoxyuridine, -cytidine