申请人:Hoechst Aktiengesellschaft
公开号:US04908478A1
公开(公告)日:1990-03-13
A single-vessel process for preparing 2-acetaminonaphthalene-6-sulfonic acid of high purity by sulfonating 2-hydroxynaphthalene with concentrated sulfuric acid, converting the 2-hydroxynaphthalenesulfonic acid formed with ammonia in the presence of ammonium hydrogensulfite into 2-amino-naphthalene-6-sulfonic acid (Bucherer reaction) and N-acetylating the latter to give 2-acetaminonaphthalene-6-sulfonic acid, which comprises, after diluting the sulfonating melt with water, substantially removing any impurities still present in the resulting aqueous solution of 2-hydroxynaphthalene-6-sulfonic acid, in particular 2-hydroxynaphthalene, by extraction with toluene or xylene and/or clarification using active carbon.
一种单釜工艺,用浓硫酸磺化2-羟基萘,将所形成的2-羟基萘磺酸与氨在硫酸氢铵存在下反应(Bucherer反应),制备高纯度的2-乙酰氨基萘-6-磺酸。然后对后者进行N-乙酰化,以得到2-乙酰氨基萘-6-磺酸。该方法包括将磺化熔体用水稀释后,通过用甲苯或二甲苯萃取和/或使用活性炭澄清,从所得的2-羟基萘-6-磺酸水溶液中实质性地去除任何仍然存在的杂质,特别是2-羟基萘。