Anti-inflammatory, analgesic, anti-rheumatic and anti-thrombotic thienothiazine derivatives having the formula ##STR1## wherein A together with the two carbon atoms forms the group ##STR2## and the dotted line indicates the double bond present in the first and last thieno structures above, R.sup.1 is lower alkyl, R.sup.2 is the radical of an aromatic heterocycle with 1 to 4 hetero atoms optionally substituted by one or two lower alkyl groups, or a phenyl radical optionally substituted by halogen, hydroxy, lower alkyl, trifluoromethyl or lower alkoxy, R.sup.3 is halogen and R.sup.3' is hydrogen or halogen, and pharmaceutically acceptable salts thereof are described.
The present disclosure relates to the technical field of drug synthesis, in particular to a method for preparing lornoxicam. The method includes the following steps: using 6-chloro-4-hydroxy-2-methyl-2-H-thieno[2,3-e]-1,2-thiazine methyl carboxylate-1,1-dioxide and 2-aminopyridine as raw materials, and xylene as a solvent; mixing the raw material and solvent, and adding a stabilizer, to obtain a mixture; subjecting the mixture to an ammonolysis; cooling the resulting reactant; conducting a vacuum concentration to remove the solvent; adding an organic solvent and slurrying, and filtering, to obtain a crude lornoxicam; and refining the crude lornoxicam to obtain the lornoxicam. In the present disclosure, p-toluenesulfonic acid is used as a stabilizer to reduce the reaction temperature and promote the reaction to proceed forward, thereby improving the quality and yield of the product.