5-(4-Hydroxyanilino)-8-(4-methylanilino)-lnaphthalenesulfonic acid?in the presence of Copper sulfate monohydrate with Sodium polysulfide ethanol solution heating, reflux 50 hours, then add the Sodium nitrite, again boiling 6 hours, steamed out ethanol, in 50 ~ 60 ℃ blowing air make precipitation. This indophenol?is by 8-(P-toluidino)naphthalene-1-sulfonic acid??and where did 4-Aminophenol with Sodium hypochlorite oxidation of mixture, then use Sodium hydrosulfide reduction and have to (BIOS 1155, – 12)
