The Thermal Decomposition of N,O-Diacyl-N-t-butylhydroxylamines. II. Thermal Rearrangement of O-Acyl-N--N-t-butylhydroxylamines

Article abstract of DOI:10.1246/bcsj.54.1781

Several O-acyl-N-<2-(methylthio)benzoyl>-N-t-butylhydroxylamines (1) were prepared and their thermal decompositions were studied.The thermal decomposition of 1 at 200 deg C in o-dichlorobenzene gave N-t-butyl-2-(acyloxymethylthio)benzamide (4), the carboxylic acid derived from the acyl part of 1, and 2-t-butyl-1,2-benzothiazol-3(2H)-one as the main products, together with small amounts of 4H-3,1-benzoxathiin-4-one, N-t-butyl-2-(methylthio)benzamide, methyl ester of the carboxylic acid, and N-t-butylamide.The benzamide (4) was found to be an initial product of the thermolysis and the subsequent decomposition gave the carboxylic acid and other products.Pummerer type reaction, via acylaminosulfonium ion as the intermediate, was suggested for the thermal decomposition of 1 since similar products were also obtained by the Pummerer reaction of N-t-butyl-2-(methylsulfinyl)benzamide with acylating reagents.