发明名称 |
Process for the preparation of 1-amino-2-ethoxy-naphthalene-6-sulphonic acid |
摘要 |
A process for the preparation of 1-amino-2-ethoxy-naphthalene-6-sulphonic acid from 2-hydroxy-naphthalene-6-sulphonic acid which comprises: A. contacting 2-hydroxy-naphthalene-6-sulphonic acid with at least an equimolar amount of an alkali metal nitrite in aqueous solution or suspension in the presence of hydrochloric acid, solution or suspension having a pH in the range of 2 to 5 and being at a temperature of 0 DEG to 20 DEG C.; B. reducing the reaction product of step A in an aqueous suspension by contacting the same with excess iron in the presence of at least an equivalent amount of iron-II ions, relative to the reaction product obtained according to step A, in the presence of a mineral acid at a temperature from 50 DEG to 120 DEG C., and treating the thus-obtained reaction mixture with aqueous alkali metal hydroxide in the presence of iron oxide; C. contacting the product of step B with excess acetic anhydride in an aqueous solution or suspension at a pH in the range of 3 to 10 at a temperature from 0 DEG to 100 DEG C.; D. contacting the product of step C with an ethylating agent in the presence of an acid binding agent in an aqueous-organic solvent or diluent in a pH range from 8 to 14 at a temperature from 20 DEG to 150 DEG C.; and E. deacetylating the product of step D by contacting the same at reflux with an aqueous alkali metal hydroxide.
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申请公布号 |
US4341719(A) |
申请公布日期 |
1982.07.27 |
申请号 |
US19810238327 |
申请日期 |
1981.02.26 |
申请人 |
BAYER AKTIENGESELLSCHAFT |
发明人 |
PUETTER, ROLF;PFISTER, THEODOR;NIESE, MANFRED;WENZL, PETER |
分类号 |
C07C309/50;C07C67/00;C07C301/00;C07C303/02;C07C303/22;C07C309/47;(IPC1-7):C07C143/66 |
主分类号 |
C07C309/50 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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