69977-87-3Relevant academic research and scientific papers
THERMAL FISSION OF HYDROXYLAMINE DERIVATIVES WITH NEIGHBOURING-GROUP-PARTICIPATION BY THIOETHER FUNCTIONS: PREPARATION OF 1,2-BENZISOTHIAZOLES
Lawson, Alexander J.
, p. 357 - 368 (2007/10/02)
Some of the factors influencing the preparation of 1,2-benzisothiazoles from 2-(alkylthio)phenyl-substituted oximes are discussed.Good yields of 3-aryl-1,2-benzisothiazoles 4 may be obtained from readily available precursors.Reaction takes place under particularly mild conditions when a t-butylthio function is situated anti to the leaving group at oxime-nitrogen and S-N overlap is not restricted by ring-strain in the transition-state.The corresponding N-methyl-hydroxamic acid derivatives 2 give good yields of 2-methyl-1,2-benzisothiazol-3(2H)-one 13 only when a t-butylthio substituent is present, e.g. in 2f.The ethylthio- and i-propylthio-analogues 2d and 2e give the vinylthioethers 12, while the methylthio derivatives 2a-c undergo a novel rearrangement to "Pummerer" esters.The preparation of the polycyclic compounds fluoreno-1,2 thiazole 7 and 2,2'-bi(2H-fluoreno-1,3-thiazine) 8 is described.
