- Synthesis of a few cyclothiadiazanones and aminosulfonyl benzamides from saccharin
-
Saccharin is hydrolyzed with two different acids to yield 1,2-di-acid. The di-acid, on chlorination with phosphorous pentachloride, gave 2-chlorosulfonylbenzoyl chloride. The 2-chlorosulfonylbenzoyl chloride on hydrazinolysis gave benzothiadiazinetrione, while with phenyl hydrazine it selectively yielded 2-phenylbenzothiadiazinetrione. 2-chlorosulfonoylbenzoyl chloride with different aromatic 1,2- diamines resulted in dibenzothiadiazocine derivatives. Electron-donating groups in the diamine facilitate while the electron-withdrawing groups retard the cyclization. However, aliphatic diamines, aniline and substituted anilines readily gave acyclic aminosulfonyl carboxybenzamides on condensation with 2- chlorosulfonylbenzoyl chloride. The di-acid and anhydride did not react with either hydrazine/phenyl hydrazine or amines to give the above products. However, when its ester derivative, isopropyl-2- chlorosulfonylbenzoate, condensed with hydrazine, it gave benzothiadiazinetrione. But the ester failed to react with phenyl hydrazine. All the condensation reactions were carried out at room temperature.
- Ramana, P. Venkata,Reddy, A. Ram
-
experimental part
p. 71 - 81
(2010/10/04)
-
- N,N′-Linked 1,2-benzisothiazol-3(2H)-one 1,1-dioxides: synthesis, biological activity, and derived radicals
-
A number of N,N′-linked benzoannelated isothiazol-3(2H)-one 1,1-dioxides, not available via oxidation of isothiazolium salts, were obtained with good yields by reaction of N-amino heterocycles with 2-chlorosulfonylbenzoyl chloride and evaluated for their inhibitory activity toward human leukocyte elastase (HLE) and acetylcholinesterase (AChE). 2-(Phthalimid-1-yl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide and 2-(2-methyl-4-oxo-3(4H)-quinazolinyl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide were found to be inhibitors of HLE and tested as potential precursors of nitrogen-centered radicals using 266 nm laser flash photolysis.
- Zakharova, Valeria M.,Brede, Ortwin,Gütschow, Michael,Kuznetsov, Mikhail A.,Zibinsky, Mikhail,Sieler, Joachim,Schulze, B?rbel
-
body text
p. 379 - 384
(2010/03/01)
-
- Development of a scalable process for CI-1034, an endothelin antagonist
-
A concise, convergent multikilogram synthesis of CI-1034 (1), a potent endothelin receptor antagonist, is described. A 15-step preparation from commercially available o-vanillin and benzenesulfonyl chloride employs a remarkably robust Suzuki coupling between a boronic acid and an aromatic sulfonate ester as the key synthetic step. A scalable route capable of producing multikilogram quantities of CI-1034 with no chromatographic steps is described in this contribution. Improvements to the process included using a 4-fluorobenzenesulfonate ester as a suitable substitute for the triflate group in the Suzuki reaction and the use of MgCl2 as a substitute for TiCl4 in a Dieckmann condensation to provide the benzothiazine dioxide core.
- Jacks, Thomas E.,Belmont, Daniel T.,Briggs, Christopher A.,Horne, Nicole M.,Kanter, Gerald D.,Karrick, Greg L.,Krikke, James J.,McCabe, Richard J.,Mustakis, Jason G.,Nanninga, Thomas N.,Risedorph, Guy S.,Seamans, Ronald E.,Skeean, Richard,Winkle, Derick D.,Zennie, Thomas M.
-
p. 201 - 212
(2013/09/04)
-
