Unexpected desulfonation of alpha-phenylsulfonyl enaminoacrylates during their cyclisation to new N-aryl 4H-1,4-benzothiazine-1,1-dioxides

Authors
Lopez, SE Charris, J Urdaneta, N Canelon, CE Salazar, J Herrera, J Angel, JE
Citation
Se. Lopez et al., Unexpected desulfonation of alpha-phenylsulfonyl enaminoacrylates during their cyclisation to new N-aryl 4H-1,4-benzothiazine-1,1-dioxides, PHOSPHOR SU, 175, 2001, pp. 87-97
Citations number
9
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS
ISSN journal
10426507 → ACNP
Volume
175
Year of publication
2001
Pages
87 - 97
Database
ISI
SICI code
1042-6507(2001)175:<87:UDOAED>2.0.ZU;2-O
Abstract
Ali unexpected desulfonation of alpha -phenylsulfonyl-enaminoacrylates occu rred during their cyclisation to novel 6,7-dichloro-N-aryl-4H-1,4-benzothia zine-1,1-dioxides using potassium carbonate and silver nitrate in DMF. This last cyclisation step was not completed in five hours of reaction but, ins tead of higher yields of the desired cyclic 4H-benzothiazines, a mixture of the above mentioned target compounds and desulfonated N-formyl-2-aryl-enam inoacrylates were obtained.