183. Isomerization of N-- and N-benzotriazoles

Article abstract of DOI:10.1002/hlca.19910740831

The thermal isomerizations of N-<α-(alkylthio)alkyl>- and N-<α-(arylthio)alkyl>benzotriazoles have been investigated under N2 atmospheres i) in toluene, xylene, MeOH, or EtOH, in the presence of acid catalysts and ii) in the absence of solvent.The sulfide isomerization rates depend on the number of H-atoms carried by the C-atom attached to the N-atom of the benzotriazole: tertiary (no hydrogen) > secondary (1 hydrogen) > primary (2 hydrogens).The results support an isomerization mechanism involving a heterolytic N-C bond cleavage with formation of sulfonium/carbonium and benzotriazolate ions.