A study on the mass spectrometric fragmentation of N-styrylsaccharins I (R = o-, m-, p-Me, p-MeO, p-Ac m-NO2, o-NO2) is reported on the basis of high resoln. and metastable measurement under 70 eV electron bombardment. The title compounds usually show strong mol. ion peaks. Most of them are base peaks. The key fragments [M-HSO2]+ probably originate from parent compounds via loss of SO2 with ortho-hydrogen or the hydrogen from the substituted benzene rings. A pronounced ortho effect is observed in case of styryl substituted by o-NO2, of which m/z 119, as base peak, is formed by migration of oxygen from the nitro group.

Key words: MASS SPECTROGRAPHY, BENZENE P, PYROLYSIS, ORGANO SULFUR COMPOUNDS, PALLADIUM, STYRENE P, BENZOTHIAZOLE P, MERCURY CHLORIDE, ELECTRON BOMBARDMENT