
%0 Journal Article
%A Clark-Lewis, JW 
%A Moody, K 
%T Heterocyclic compounds from alloxan and amines. XIII. Phenazine freeradical betaines and their dehydro dimers derived from alloxan and 2-aminodiphenylamines
%J Australian Journal of Chemistry
%D 1971/12/01
%V 24
%N 12
%P 2593-2610
%K 
%R https://doi.org/10.1071/CH9712593
%U https://www.publish.csiro.au/paper/CH9712593 
%X 2-Amino-N-alkydiphenylamines and 2-aminotriphenylamines react with alloxan at room temperature to give green, intensely coloured, stable, free-radical betaines (dihydrophenazinioylbarbiturates). Heating the free-radical betaines alone or in a solvent gives rise to blue dimers. 3,7-Disubstitution of the phenazinioyl nucleus by methyl groups prevents formation of the blue dimers, which are therefore considered to arise by dimerization at the 3-position, followed by dehydrogenation. Dimerization of 3,7- dimethyldihydrophenazinioylbarbi- turates gives deep green 3,3?-dimers in which the 3,3?-methyl substituents prevent the dehydrogenation step entailed in the formation of the blue dehydro dimers.     A violent explosion occurred in two instances during preparation of phenazine by oxidative sublimation of crude dihydrophenazine by Morley's method (J. chem. Soc., 1952, 4008). 
