Patent Number: 6,252,069

Title: Method for the production of 3-isopropyl-1H-2, 1,3-benzothiadiazine-4 (3H)-one-2,2-dioxide

Abstract: A process for preparing 3-isopropyl-1H-2,1,3-benzothiadiazin-4 (3H)-one 2,2-dioxide (I) or a salt of I ##STR1## which comprises reacting anthranilic isopropylamide II ##STR2## simultaneously with sulfur trioxide or chlorosulfonic acid in the presence of an organic base or with adducts of sulfur trioxide and organic bases and phosphorus oxychloride at from 50.degree. C. to the reflux temperature, followed, if appropriate, by conversion into its salts, is described.

Inventors: Merkle; Hans Rupert (Ludwigshafen, DE), Worz; Otto (Friedelsheim, DE), Fretschner; Erich (Neckarsteinach, DE), Hansen; Hanspeter (Ludwigshafen, DE), Muller; Albrecht (Ludwigshafen, DE), Benz; Kurt (Romerberg, DE)

Assignee: BASF Aktiengesellschaft

International Classification: C07D 285/00 (20060101); C07D 285/16 (20060101); C07D 285/16 ()

Expiration Date: 06/26/2018