2,6-Dinitrotoluene-4-sulfonic Acid, crystallizes as a hydrate in the form of pale yellow crystals, which soften at 110 ℃, dehydrate at 140 ℃, and melt at 165 ℃.
Reduction of 2,6-Dinitrotoluene-4-sulfonic Acid with sulfide gives 2- amino-6-nitrotoluene-4-sulfonic acid, and reduction with iron – acid gives 2,6-diaminotoluene-4-sulfonic acid [98-25-9]. 2,6-Dinitrotoluene-4-sulfonyl chloride [80198-19-2] is obtained from 2,6-Dinitrotoluene-4-sulfonic Acid by treatment with thionyl chloride. Reaction of this sulfonyl chloride with an alkylamine followed by hydrogenation leads to a readily accessible series of symmetrical diaminotoluenesulfonamides.
2-Nitrotoluene is sulfonated to form 2-nitrotoluene-4-sulfonic acid; the reaction mixture is diluted with 90 % sulfuric acid, and sodium nitrate is added over 6 h at 80 ℃. After a further 1 h at this temperature the reaction mass is poured into water and the sodium salt of the product is salted out by addition of sodium sulfate. After being washed acid-free with brine, the yield of 2,6-Dinitrotoluene-4-sulfonic Acid is ca. 80 %.