Mass Spectrometric Study of Heterogeneous Reactions of Transformations of Molecules of Butyrophenone Derivatives During Adsorption on a Hot Surface of Tungsten Oxide

The results of the mass spectrometric studies of heterogeneous transformations of molecules of psychotropic drugs-piperidine and piperazine derivatives of butyrophenone haloperidol, trifluperidol, droperidol, and azaperone during adsorption on a hot surface of tungsten oxide-have been presented. The relationship between the channels of heterogeneous reactions and the nature of the adsorption centers in the molecules has been established. Ion current lines characteristic of the products of heterogeneous reactions of dehydrogenation, dissociation, and dehydrolysis of molecules with the elimination of up to two water molecules formed during aromatization of amine rings and hydrogen rearrangement with the participation of oxygen of the carbonyl group have been found in the mass spectra. A shift in the maximum yield of heterogeneous reactions towards low emitter-converter temperatures with an increase in the degree of dehydrogenation and dehydrolysis of radicals in the adsorbed layer has been found. At the same time, estimates have shown that within the emitter temperature range from 850 K to 1200 K, the lifetime of radicals in the adsorption layer is reduced from fractions of a second to tens of nanoseconds. At relatively high emitter temperatures (from 800 K), current lines of monomolecular decays of metastable parent ions have been detected. When using the surface of tungsten oxide as a positive ion converter, a high efficiency (up to 98%) of surface ionization of desorbed radicals has been established, making it possible to trace the complete picture of the heterogeneous reactions occurring in the adsorbed layer.