Preparation of Pyrrolo[2,1-b][1,3]benzothiazin-9-ones via Intramolecular Sulfenylation of an N-Acylpyrrole
Document Type
Article
Publication Date
6-1-1992
Abstract
Pyrrolo[2,1-6][1,3]benzothiazin-9-one (6a) was synthesized in 45% overall yield from thiosalicylic acid in six steps. The title compound (88%) and its 1-trifluoroacetyl (83%) and 1-formyl derivatives were synthesized via intramolecular reaction of 1-(2-ethylsulfinyl) benzoylpyrrole (5) by thermal cyclization or treatment with trifluoroacetic anhydride or DMF/POCl3, respectively. The key step in each case is formation of the heterocycle by sulfoxide activation followed by C-S bond formation via attack of sulfur. Reaction of 6a with common electrophiles (trifluoroacetic anhydride (86%), POCl3/DMF (75%), and acetyl nitrate) indicates that C-1 is the predominant site of electrophilic substitution. © 1992, American Chemical Society. All rights reserved.
Publication Title
Journal of Organic Chemistry
Recommended Citation
Tafel, K.,
&
Bates, D.
(1992).
Preparation of Pyrrolo[2,1-b][1,3]benzothiazin-9-ones via Intramolecular Sulfenylation of an N-Acylpyrrole.
Journal of Organic Chemistry,
57(13), 3676-3680.
http://doi.org/10.1021/jo00039a030
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/8055