The method according to claim 1, wherein 2-amino-5-trifluoromethylpyridine, 2-amino-5-nitropyridine or 2-amino-5-cyanopyridine is reacted with chlorine to form 2-chloroamino-5-trifluoromethylpyridine, 2-chloroamino-5-nitropyridine or 2-chloroamino-5-cyanopyridine, respectively, which is then subjected to a rearrangement reaction in the presence of at least one carboxylic acid selected from the group consisting of formic acid, acetic acid and propionic acid, to obtain 2-amino-3-chloro-5-trifluoromethylpyridine, 2-amino-3-chloro-5-nitropyridine or 2-amino-3-chloro-5-cyanopyridine.
