Thoination of N-alkyl-O-acyl hydroxamic acid derivatives via Lawesson's reagent

N-alkyl-O-acyl thiohydroxamic acid derivatives were prepared in good yields by the treatment of their parent hydroxamic acids with Lawesson's reagent. Some of these thiohydroxamic acid derivatives exhibit the ability to undergo rearrangement under basic conditions possibly via [3,3]-sigmatropic in moderate to good yields similar to their parent hydroxamic acids.