Mass spectral fragmentation pattern of heterocycles part I. 1,4-Benzoxthians

The mass spectral fragmentation pattern of a series of substituted 1,4-benzoxathians is reported. The di-substituted compounds show a characteristic fragment peak at mass 137. This same fragmentation peak is also present in some of the monosubstituted compounds. In the former case the 137 mass peak is quite intense and is the base peak for some of the di-substituted-1, 4-benzoxathians. The mass peak at 137 has been assigned the empirical formula of C₇H₅OS.