44HYDROXYY2HHNAPHTO211E122 THIAZINEE33CARBOXYAMIDEE111DIOXIDE AND MEDICAL COMPOSITE CONTAINING THE COMPOUND

4-Hydroxy-2H-naphtho[2,1-e]-1,2-thiazine-3-carboxamide 1,1-dioxides of the adjoining formula I in which Ar is a phenyl, 3-chlorophenyl, 3-bromophenyl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 3-tolyl, 2-methoxyphenyl or 3-methoxyphenyl group are prepared by subjecting a corresponding 3-oxo-naphtho[2,1-d]isothiazoline-2-acetic acid arylamide 1,1-dioxide of the formula II to a base-catalysed rearrangement. The resulting compounds can be converted by methylation or ethylation using the appropriate halides into the corresponding compounds substituted by methyl or ethyl, respectively, on the ring nitrogen. The compounds are distinguished by very good anti-inflammatory and/or antithrombotic properties and can be used as active ingredients in corresponding pharmaceuticals. They inhibit both the adhesion and the aggregation of blood platelets.