| 摘要 |
<p>The invention provides a process for the continuous diazotization of primary aromatic amines by reacting an aqueous solution or suspension of the amine in a mineral acid with an aqueous sodium nitrite solution. To this end, the lower portion of a cylindrical diazotization vessel placed in upright position is fed continuously with an aqueous mineral acid solution or suspension of a diazotizable primary aromatic amine. At the same time, the vessel is fed, via one or more inlets arranged one above the other so as to open laterally thereinto, with an aqueous sodium nitrite solution, the amine and nitrite being used in stoichiometric proportions, or the nitrite being used in a stoichiometric deficiency and the acid being used in an excess of about 1 to 3 equivalents per amine equivalent in the mineral acid solution. The resulting mixture is reacted while producing a laminar flow of liquid matter at temperatures of about 5 DEG to 30 DEG C. Next, reaction mixture is removed, in accordance with the diazotization velocity of the particular amine used, from the upper portion of the diazotization vessel at a place where the reaction mixture is substantially free from nitrous acid, said place being situated in the vessel at a level which is the higher the lower the diazotization velocity of the amine used. The reaction mixture removed is finally filtered and diazonium salt-containing solution is delivered to a sojourn zone.</p> |
