| 摘要 |
PROBLEM TO BE SOLVED: To produce a new aminobenzenesulfonic acid derivative monohydrate useful for producing a medicinal composition effective in preventing or treating ischemic cardiopathy, cardiac failure and hypertension, etc. SOLUTION: This new aminobenzenesulfonic acid derivative monohydrate is represented by the formula [R<1> is H, an alkyl, a halogen, etc.; R<2> is H, an alkyl or cyano, an aralkyl, etc.; (n) is an integer of 1-4], e.g. 2-(1-piperazinyl)-5- methylbenzenesulfonic acid monohydrate. The compound represented by formula I is obtained by suspending an aminobenzenesulfonic acid derivative anhydride in water or a hydrous organic solvent or carrying out the crystallizing treatment of the dissolved solution and drying the formed crystal. The organic solvent to be used is a water-soluble organic solvent such as methanol or ethanol. The suspending treatment of the anhydride is preferably conducted by stirring the mixture at normal temperature for >=2hr. |
