
%0 Journal Article
%A Clark-Lewis, JW 
%A Taylor, MR 
%A Westphalen, J 
%T Heterocyclic Compounds from Alloxan and Amines. XIV. Structure of Even-Electron Products Derived from Free-Radical Betaines
%J Australian Journal of Chemistry
%D 1979/09/01
%V 32
%N 9
%P 1943-1947
%K 
%R https://doi.org/10.1071/CH9791943
%U https://www.publish.csiro.au/paper/CH9791943 
%X X-ray crystallographic determination of structure has shown that the even-electron product obtained thermally from 5-(10-phenyl-5,10-dihydro-5-phenazinioyl)-1,3-dimethyl-4-barbiturate (1) (e.g. by heating in benzene) has the structure 1,3-dimethy1-5-(10-phenyl-2,10-dihydrophenazin-2-ylidene)- hexahydropyrimidine-2,4,6-trione (3) instead of the previously supposed dehydro dimer structure (2). Crystals of compound (3) are triclinic, P&#299;, a 11·014(3), b 9·343(3), c 10·927(3) Å, &#945; 110·47(4), &#946; 64·99(4), &#947; 101·47(4)º, Z = 2. Full-matrix least-squares refinement gave R 0·09. The rearrangement that occurs in the conversion of the free-radical betaine (1) into the trione (3) is a novel type of N to p-aromatic rearrangement which presumably entails dissociation followed by recombination and oxidation. 
