Mass spectra of some α‐substituted phenyl‐α,α′‐dimethoxyl ketones and their derivatives

Abstract

The mass spectra of some a-substituted phenyla,a'dimethoxyl ketones (compounds 1) and their 2 , 6 dinitrophenylhydrazones (compounds 2) and semicarbazones (compounds 3) have been studied. The characteristic fragments at m/z (M -73) from compounds 1, m/z (M -253) from compounds 2 and m/z (M -130) from compounds 3 are abundant and proposed to be [ ArCROCH, I +. Fragmentations yielding [ M + -49) from compounds 2 are abnormal and probably involve the methoxyl and nitro group. The intense peak at m/z 130 due to [ CH,0CH2CNNHCONH, 1 + from compounds 3 corresponds to acleavage of the molecular ion. Some other fragments from these new compounds are interpreted in this paper.