The mass spectrometry of phenothiazines—I. 10‐alkylphenothiazines

The fragmentation of six substituted 10-alkylphenothiazines is discussed. Predominant expulsion of OH, SO and O occurs from the molecular ions of 10-alkylphenothiazine-5-oxide derivatives, the relative extent depending upon the configuration of the 10-substituent. The simultaneous elimination of two OH radicals from the molecular ion of 10-alkylphenothiazine-5-sulphone derivative is also observed.