Mass spectrometer as a probe in the synthesis of 2-substituted-3-phenyl-4 (3H)-quinazolinones

The ortho interaction of the anilide function with the N-acyl group in 2-acylaminobenzanilides 1-7 on electron impact leads to the elimination of H2O from the molecular ions, resulting in the formation of 2-substituted-3-phenyl-4-(3H)-quinazolinone radical cations. This mass spectrometric reaction has been successfully implemented in the laboratory to synthesize 4 (3H)-quinazolinones 8-14 by the thermolysis of 2-acylaminobenzanilides. The mechanisms and ion structures proposed in the mass spectral study are supported by high resolution data and Collision Activated Decomposition (CAD)-B/E linked scan spectra.