Method A is based on the ability of electron deficient phenyl halides 3 a—f to react readily by nucleophilic aro-matic substitution (SNAr) 9" 10 with a weak nucleophilic carbon center like the anion of the ethyl (trifluorometh-anesulfonyl) acetate (1)(Scheme 1). 1'3 The phenyl halide 3a—f was added to a DMF solution of the anion prepared by the addition of one equivalent ''of potassium tert-butoxide to one equivalent of 1. After two days, the solvent ...
