FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to the improved method for preparing 2-naphthol-6,8- disulfoacid. 2-Naphthol-6,8-disulfoacid is synthesized by sulfonation of 2-naphthol with fuming sulfuric acid (oleum), precipitation of product as ammonium-potassium salt followed by filtration or separation of prepared suspension by centrifugation and washing out paste prepared. Precipitation is carried out by gradual pouring out sulfomass into an aqueous solution containing potassium chloride and ammonia taken in the amount 250- -270 g and 110-130 g per 1000 g of undiluted sulfomass, respectively. Washing out is carried out with water or potassium chloride solution. Invention provides preparing the end product with the yield 92-95% by stages of isolation, filtration and washing out. EFFECT: improved preparing method, elevated yield of product. 2 cl, 5 ex
| Title | Year | Author | Number |
|---|---|---|---|
| METHOD FOR PREPARING 2-NAPHTHOLSULFOACIDS | 2002 |
|
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