Benzidine Rearrangement


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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Benzidine Rearrangement

 

the conversion of hydrazobenzene (I) by the action of dilute mineral acids into 4,4’-diaminodiphenyl, or benzidine (II); one of the types of intramolecular rearrangement. A small amount of 4,2’-diaminodiphenyl, or diphenyline (III), is formed simultaneously:

In the naphthalene series benzidine rearrangements can take place in the absence of acids. The benzidine rearrangement is realized in that case if the hydrazobenzene contains various substituents in the benzene nuclei. However, if there is a substituent in the para position, the result is a semibenzidine (or semidine) rearrangement with the formation of aminodiphenylamine:

The benzidine rearrangement is widely used in the production of azo dyes and to obtain tolidine, dianisidine, and so on.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.