Ortho effects in organic molecules on electron impact. 12—Mechanism of the H2O loss from the molecular ion of 2‐(phenylamino)benzoic acid

The mass spectrum of 2-(phenylamino)benzoic acid is characterized by the presence of the base peak at m/z 195, formed by the expulsion of H2O from the molecular ion. A mechanism for the water loss, involving the COOH and NH functions followed by cyclization leading to the molecular ion of acridone, is proposed based on the study of the substituted derivatives and MIKE spectra.