QUINONOID OXIDATION PRODUCTS OF 

 DIANISIDINE, AND THEIR POLYMERISATION. 



By James Moir. M.A.. D.Sc. 



Previous work on the formation of quinonediimines is 

 represented by Willstaetter and Pfannenstiel's work on oxida- 

 tion of phenylenediamine.* In the diphenyl series the chief 

 references are : Willstsetter and Kalbf, whose papers deal with the 

 oxidation of benzichne and its meth}-! derivatives to coloured sub- 

 stances which the authors consider to be quinonoid : see also the 

 present author's work on *' diphenoquinone-diimine " and its 

 3-3'-dimethyl derivative, and on their quinhydronesj ; " Oxida- 

 tion-products of benzidine "|| ; also " New derivatives of dipheno- 

 quinone.§ 



The present work deals with certain beautiful and compara- 

 tively stable substances analogous to the above, obtained by mild 

 oxidation of dianisidine (3-3' dimethoxy-benzidine). One of 

 these is undoubtedly a quinhydrone, and wiU be termed dianis- 

 im'mo'quinhydrouc . to indicate that it is a compound of the un- 

 known 3-3'-dimethoxy-diphenoquinone-diimine with dianisidine ; 

 and its formula may be written in monomolecular form by mak- 

 ing one only of the benzene-rings quinonoid. (This is merely to 

 save space, since it involves writing a trivalent carbon-atom. 

 This formula is : 



NH: ( y^\ y^NH, 



CH,^0 OCH3 



The basal idea in this is, I think, the same as what is meant by 

 certain German writers in using the term nicriquinone^ but I, 

 personally, see no advantage in abandoning the term quinhydrone. 

 x'^.s regards the corresponding quinonediimine, I shall bring 

 forward evidence to show that, when formed, it immediately 

 polymerises to an azodye. This behaviour was suspected in the 

 case of Willstaetter's " dipheno-quinone-diimine," which I now 

 consider to have the formula 



NH„^ >K / N.X > — < V-NH 



This is perfectly analogous to the behaviour of ordinary quinone- 

 diimine, which in contact with water apparently polymerises to 

 azoaniline 



* Berichte, 1904, p. 4605; see also Rer.. 1894, p. 480; 1904, pp. 1494 and 

 2906. 



f Berichte, 1904, p. 3761, and 1905, p. 1232. 



t "Benzidine Chromate," Proc. C.S., Lond. 



il Trans Roy. Soc. S.Afr., 1912, p. 205. 



§ Rept. S.A. Assn. for Adv. of Sc. Bulawayo, T911, p. 253 



