DE605577C - Process for the preparation of solid diazonium salts - Google Patents

Description

Process for the preparation of solid diazonium salts It has been found that ß the simple, mineral acid diazonium salts from 4-halo-2-aminodiphenyl ethers with very good yields from their aqueous mineral acid solutions, as they are for. B. obtained with diazotization of the 4-halo-2-aminodiphenyl ethers can be deposited by salting out. Since the diazo solution of the 4-halo-2-anvnodiphenyl ethers contains a very large excess of mineral acid from its preparation (see patent specification 544 057, p. I, line 19 and following) and such mineral acid diazonium salts are known to be very easily soluble in water, so it could not be foreseen that from such solutions by simply salting out without neutralizing the excess acid and without using arylsulfonic acids, as z. B. happens according to the process of patents 484905, 544057 and 572269 , well-preserved diazo salts would be produced directly. Even before the process of patent 545 852, the new process has the advantage that the special measure of neutralizing the acidic diazo solutions is avoided. In relation to the patent specifications mentioned, the present method is therefore distinguished by its simplicity and, in comparison with the same, represents a significant technical advance. EXAMPLE i 27o parts of finely powdered sulphate of 4-chloro-2-arninodiphenyl ether are introduced into a solution of 130 parts of nitrosylsulphuric acid in zoo parts of 85% sulfuric acid at 15 to 20 °. Stirring is then continued for about an hour until the diazotization has ended. The strongly sulfuric acid diazotizing melt is then discharged onto 730 parts of ice and 600 parts of ammonium sulfate are added to the resulting solution. As a result, the diazonium sulfate is deposited with an almost quantitative yield. After prolonged stirring, it is filtered off from the aqueous sulfuric acid liquid and dried at about 45 °.

The same procedure is followed with 4-bromo-2-aminodiphenyl ether.

Example 2 256 parts of 4-chloro-2-aminodiphenyl ether chloride are used with 73o parts of 20 weight percent hydrochloric acid and 36o parts of 20 weight percent Sodium nitrite solution diazotized. In the filtered diazo solution there are 32o parts hsodium chloride dissolved. The precipitated diazonium chloride is at low temperature filtered off and further processed in a suitable manner. Instead of using sodium chloride can e.g. B. also be salted out with anhydrous magnesium chloride. example 3 If the filtered diazo solution obtained according to Example 2 is mixed with 250 parts of -Bromo-potassium- added, the diazonium bromide precipitates in yellow crystals, which are filtered off and can be further processed with special care. Example q. 22o parts q.-Chloro-2-aminodiphenyl ethers are finitely 300 parts of 25 percent strength by weight nitric acid Emd 36o parts - weight percent sodium nitrite solution diazotized. From the filtered Diazo solution with 500 parts of sodium nitrate becomes the diazonium nitrate in yellow crystals failed. It can be filtered off and expediently after dilution with suitable inorganic Thinners must be dried with particular care.

Diazonium nitrate is also obtained from hydrochloric acid diazo solution due to sodium nitrate easily separable. Example 268 parts of neutral sulfate of q-chloro-2-aminodiphenyleth, ers are with zooo parts 34 weight percent sulfuric acid and 36o parts 20 weight percent Diazotized sodium nitrite solution. In. the filtered diazotization becomes 45o parts dissolved anhydrous sodium sulfate. This in almost theoretical yield Semi-solid deposited diazonium sulfate soon solidifies to form crystals. These will filtered off at ordinary temperature and, as usual, made ready. Instead of with sodium sulphate can just as well with sufficient amount of ammonium sulphate or dry Magnesium sulfate, e.g. B. the composition Mg S 04 # 2 H2 O, are salted out.

Finitely q-bromo-2-arninodiphenyl ether is proceeded in exactly the same way.

Are the present salts for the preparation of diazo preparations for serve the trade for the production of ice colors, so they can with the usual Diluents are mixed.

Claims (1)

PATENT CLAIM: Process for the production of solid diazonium salts, therein consisting that the simple, mineral acid diazonium salts from q.-Halogen-2-aminodiphenyläthem separated from their aqueous mineral acid solutions by appearance and from the Liquid are separated.