Although there are many conceivable ways to functionalize, and specifically carboxylate, 2-chloro-4-(trifluoromethyl)pyridine optionally at all three vacant positions, it is more straightforward to prep. only 2-chloro-4-(trifluoromethyl)pyridine-3-carboxylic acid from this precursor and 6-chloro-4-(trifluoromethyl)pyridine-2- and -3-carboxylic acids from a different one, viz. 5-bromo-2-chloro-4-(trifluoromethyl)pyridine. In the same manner, it proved more convenient to convert 5-chloro-2-(trifluoromethyl)pyridine into only the 4- and 6-carboxylic acids and to make the 3-carboxylic acid from 3-bromo-5-chloro-2-(trifluoromethyl)pyridine. All model substrates for functionalization were readily accessible from the correspondingly substituted chloroiodopyridine through heavy halogen displacement by in situ generated (trifluoromethyl)copper. [on SciFinder (R)]