Methyl 2-methyl-4-hydroxy-2H-thieno[2,3-e]-1,2-thiazine-3-carboxylatelate-1,1-dioxide , its CAS NO. is 59804-25-0, the synonym is Methyl 4-hydroxy-2-methyl-2H-thieno[2,3-e][1,2]thiazine-3-carboxylate 1,1-dioxide .