Some new 1,2-benzothiazine derivatives with analgesic and anti-inflammatory activities.

Twenty-three new 7-halo-4-hydroxy-2H(or alkyl)-N-(3-aralkyl-2-thio- 1-hydantoinyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide derivatives were synthesized through the condensation of 7-halo-4-hydroxy-2H(or alkyl)-1,2-benzothiazine-3-carboxylic acid methyl ester 1,1-dioxides with 1-amino-2-thio-3-aralkyl-imidazolidine-4-one. The analgesic and anti-inflammatory activities of the synthesized compounds were investigated by acetic acid-induced writhing syndrome and carrageenan rat paw edema tests. In analgesic activities most compounds exhibited higher activities than acetylsalicylic acid, but in anti-inflammatory activities most compounds except compounds 24, 36, 39 showed lower activities than indometacin.