Verfahren zur Herstellung einer festen, haltbaren Diazoniumverbindung

摘要

The invention comprises a solid stable diazonium compound of the formula: and the manufacture thereof by causing the diazonium chloride of 2-amino-4:41-dichlorodiphenyl ether to separate out from aqueous solution in a solid form by salting out with an alkali metal chloride in the presence of oxalic acid or a water-soluble salt thereof. The product may be worked up to a dyeing salt with suitable standardizing agents such as partly dehydrated aluminium sulphate or anhydrous sodium sulphate. In an example, oxalic acid is added to the diazonium chloride solution while cooling to 0-5 DEG C., and precipitation is completed by adding sodium chloride.