Fused heterocycles from o-acylbenzenethiol derivatives

Abstract

The oximes of 2-acylthioanisole derivatives may be conveniently converted into 1,2-benzisothiazoles by acetic anhydride in pyridine. 3-(2-Methylthiophenyl)-1,2-benzisothiazole, prepared by this method, has been further converted into the 1,2-benzisothiazolo[2,3-b]-1,2-benzisothiazolium system. The phenylhydrazones of certain 2-acylthioanisoles are also cyclized by polyphosphoric acid to 2-(2-methylthio)phenylindoles, which are further converted into benzo[b]thieno[3,2-b]indoles by demethylation and oxidation.

Mobilizing Cu(I) for Carbon−Carbon Bond Forming Catalysis in the Presence of Thiolate. Chemical Mimicking of Metallothioneins

“…The thiolate scavenging motif used within this study was modeled after the known thermal dealkylative cyclization of 2-alkylmercapto aryl oximes to benzoisothiazoles. 23 …”

Diverse saturated heterocycles from a hydroacylation/conjugate addition cascade

“… 32 This was further activated using acetic anhydride and base, resulting in the formation of benzoisothiazole 11g in 70% yield. 33 Such a motif has relevance in a variety of FDA approved drug scaffolds, 34 one of which being ziprasidone. 35 Furthermore, cyclic sulfide 7a could also be coupled with phenylacetylene, delivering o -(1-alkynyl)phenylketone 11h.…”

Five‐Membered Heterocycles: 1,2‐Azoles. Part 2. Isoxazoles and Isothiazoles

“…Heating oximes 171 in an acetic anhydride/pyridine mixture converts them into 1,2-benzisothiazoles 172 (Scheme 9.65) [265]. This method has been used to prepare some benzo[d,d 0 ]diisothiazoles [266].…”