| 摘要 |
PURPOSE:To obtain a compound useful as a raw material for an acidic mordant dye or metal complex salt dye in high purity, by nitrating 1-diazo-2-naphthol-4- sulfonic acid, and treating the resultant product with a saline solution. CONSTITUTION:1-Diazo-2-naphthol-4-sulfonic acid is dissolved in a conc. sulfuric acid or a mixture of conc. sulfuric acid with fuming sulfuric acid, and nitrated at 5-9 deg.C by dropping mixed acid thereinto. The product is isolated by precipitating at <=35 deg.C, filtering and washing with a water, and then agitated at ordinary temperature -40 deg.C using a saline solution of 1-20wt%, preferably 3-15wt% concentration, and further isolated by such as centrifugation to obtain the aimed substance. EFFECT:Since there is a difference of solubility in saline solution between isomers formed as a by-prpduct during nitration reaction and the aimed substance, these isomers are dissolved and removed by treating the reaction product with the saline solution.
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