Mass spectra of methoxy- and dimethoxy-phenyl acetates

Abstract

The mass spectra of methoxy- and dimethoxy-phenyl acetates are described and the possibility of distinguishing between the isomers is discussed. It is shown that in all cases the primary process is loss of keten to give the phenol molecular ion, and that further fragmentation then depends on the positions of the substituents. The side-chain acetoxylated aromatic ethers display a completely different breakdown sequence which enables them to be differentiated from their nuclear acetoxylated isomers.