| 摘要 |
Process for the preparation of naphthostyril by dissolving 1,8-naphthalimide in an aqueous solution of lithium hydroxide and potassium hydroxide while heating at 40 DEG C. to 80 DEG C., cooling the solution obtained to 14 DEG C. and seeding it at said temperature with a maximum of 1 mol-% of sodium 1,8-naphthalimide per 1 mol of 1,8-naphthalimide used, then adding chlorine bleaching liquor at 10 DEG C. to 20 DEG C., reductively removing excess active chlorine after the reaction has taken place, adjusting the alkaline aqueous solution produced of the alkali-metal salt of the 1-aminonaphthal-ene-8-carboxylic acid formed to a pH of 2.0 by adding acid and isolating the naphthostyril which precipitates in this process.
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