S Takeda et al.
Chemical & pharmaceutical bulletin, 48(7), 1097-1100 (2000-08-03)
The alpha,alpha-gem-difluorination of 2',4'-difluoro-alpha-(methylthio)acetophenone (1a) with N-fluoropyridinium salts gave 2',4',alpha,alpha-tetrafluoro-alpha-(methylthio)acetophenone (3a). This reaction was accelerated by the addition of zinc chloride, zinc bromide or anhydrous iron(III) chloride, and higher yields than the reaction without additives were obtained. The gem-difluorination reaction