PROCESS FOR PREPARING N.N'-BIS-SALICYLOYL HYDRAZINE AND ITS USE

摘要

The invention relates to a method for the production of N,N'-bis-salicyloyl hydrazine by a catalytic reaction of salicylic-acid alkyl esters with hydrazine or salicylic-acid hydrazide and has the object to develop such a method in such a manner that not only an N,N'-bis-salicyloyl hydrazine with reduced eye irritation is obtained, but wherein the product is also produced with a high yield and purity. For this purpose, the invention provides that hydrazine or salicylic-acid hydrazide is heated with a 1-to-10 times excess of salicylic-acid alkyl ester in the presence of a halogenide, hydroxide or oxide of boron, aluminum or zinc to temperatures of up to 150 DEG C. The N,N'-bis-salicyloyl hydrazine prepared by the method according to the invention is suitable particularly as an additive to polymers for cable and wire insulation in power and communication engineering.