PROCESS OF SYNTHESIS 4-HYDROXY-2H-1,2-BENZOTHIAZINE-3- CARBOXAMIDES

摘要

Proposed invention refers to the field of organic chemistry, technology, specifically to the procedure of obtaining compounds 4-hydroxy-2-methyl-2H-1.2 benzothiazine-3-carboxamides,of a general formula (I), whre R has the meaning of one of the following radicals:alkyl group (C1-C6) cycloalkyl benzyl, phenyl, pyridile, methyl-pyridile pyrimidile, thiazole. Special interest when it refers to clinical practice as unsteroid antirheumatics with antiinflamatory or analgetic properties belong to : pyroxicane (4-hydroxy-2-methyl-N-(2-piridinile) 2H- 1.2 benzothiazine-3-carboxamide-1-1 dioxide), izoxicame (4-hydroxy-2-methyl-N-(5-methyl-3-isoxazolile)-2H-1.2-benzothiazine-3-carboxamide-1.1-dioxide) and sudoxicame (4-hydroxy- 2 methyl-N-2-thiazolile-2H-1.2 benzothiazine-3-carboxamide-1.1-dioxide. This invention has for specific characteristics: use of ethilesther and dimethyl formamides with natrium etoxide for opening of cycle and work on low temperatures in the mentioned phase; then methylation and final condensing with amines of the general formula NH2-R, where R is 2 pyridile, alkyl substituted with one or two alkyl groups whereas every alkyl has 1 to 4 atoms of carboxide or 5-methyl-3-isoazolile, with the use of specific cathalits and absorption means in inert solution and inert solution and inert atmosphere.