| 摘要 |
In the present invention there is disclosed a process for preparing 4,4' -dinitrostilbene-2,2'-disulfonic acid and its salts of the general formula I, in which M represents hydrogen, sodium or potassium by oxidation of 4-nitrotoluene-2-sulfonic acid in a solvent alkaline medium at a temperature in the range of 30 to 80 degC. The invented process is characterized in that as a solvent there is used a mixture containing (a) 50 to 70 percent by weight water and (b) 30 to 50 percent by weight ether alcohol, whereby the percentages are based on the sum (a + b) and ether alcohol corresponds to the formula II {CiiHi(2i+1)(OCHi2CHi2)ij-OH} (II), in which i represents a number ranging from 2 through 10 and j represents a number ranging from 1 through 6.
|
