Electron impact induced fragmentations of 2-chlorovinyl methyl sulphides

A series of 2-chlorovinyl methyl sulphides, CH₃SCR¹?CR²Cl (R¹, R² = H, Me, Et, t-Bu, Ph; R¹ = H, R² = CH₃) has been analysed under electron impact conditions. The most significant common fragmentations involve primary loss of Cl˙ and methyl radicals. Analysis of the phenyl-substituted derivative suggests that loss of CH₃˙ is a lower activation energy process than loss of Cl˙. The characteristic loss of CH₃SCl from the same derivative has been examined with respect to the structure of the resulting fragment by means of suitable model compounds.