
%0 Journal Article
%A Lister, JH 
%T Purine Studies. XXI. Benzyl Group Translocations in 9-Benzylxanthine Derivatives
%J Australian Journal of Chemistry
%D 1979/02/01
%V 32
%N 2
%P 387-397
%K 
%R https://doi.org/10.1071/CH9790387
%U https://www.publish.csiro.au/paper/CH9790387 
%X Transformation of 9-benzylxanthines into the 7-benzyl isomers occurs when these purines are heated in the presence of hydrobromic acid or benzyl bromide in an aprotic solvent. Although 9-benzyl derivatives of xanthine, 1-methyl- and 1,3-dimethyl-xanthine have been successfully isomerized in this way the reaction has not been possible with 9-benzyl-3-methylxanthine due to failure to prepare this purine. Steric effects arising from the proximity of the 3-methyl group to the 9-benzyl group have been examined by 1H N.M.R. and the resulting data correlated with structural configurations shown to be possible by using space-filling models. 
