Mass Spectrometry of Isomeric Hydroxy-Salicylanilides and Their Derivatives

The mass spectrometric behavior of two isomeric hydroxy-salicylanilides, 3′-chloro-4′-(p-chlorophenoxy)-3-hydroxy-5-iodosalicylanilide and 3′-chloro-4′-(p-chlorophenoxy)-5-hydroxy-3-iodosalicylanilide, and their trimethylsilyl and boronate derivatives, is described. The parent compounds exhibit very similar spectra; however, the presence or absence of characteristic fragment ions in the spectra of the derivatives makes possible the differentiation of these isomers.