Direct nucleophilic substitution of polyfluorobenzenes with pyrrole and 2,5-dimethylpyrrole

Abstract

A series of novel N-pyrrolyl-, N-(2,5-dimethyl)pyrrolyl- and N-(2,5-dithiophen-2-yl)pyrrolyl- partially fluorinated and/or fully substituted benzenes have been prepared by the nucleophilic substitution of fluorine (SNAr) in hexafluorobenzene, 1-pentafluorophenyl-1H-pyrrole; 2,5-dimethyl-1-pentafluorophenyl-1H-pyrrole; 2,5-di(thiophen-2-yl)pentafluorophenyl and 2,3,5,6-tetrafluoroterephtalonitrile. The observed substitution pattern indicates the gradual defluorination of particular fluorine atoms depending on the nature and amount of the used nucleophile (pyrrole/NaH vs. 2,5-dimethylpyrrole/NaH).