
%0 Journal Article
%A Williamson, J 
%A Coller, BAW 
%T Kinetics, Stoichiometry and Mechanism in the Bromination of Aromatic Heterocycles. VI. Aqueous Bromination of Furan, Pyrrole and Thiophen
%J Australian Journal of Chemistry
%D 1979/11/01
%V 32
%N 11
%P 2423-2432
%K 
%R https://doi.org/10.1071/CH9792423
%U https://www.publish.csiro.au/paper/CH9792423 
%X Furan is oxidized to butenedial by electrogenerated bromine in aqueous solution, while thiophen under the same conditions is converted into 2-bromo-and 2,5-dibromo-thiophen. The reaction of pyrrole appears to approach the encounter-controlled limit. For transfer of Br+ from Br2 (aq., 25ºC) to the 2(5)-positions in these systems, bimolecular rate constants, kobi/dm3 mol-1 s-1, are as follows :    furan       thiophen        2-bromothiophen 108-1010   2x90 x 104 ± 5%  2 x 5.2 x 104 ± 4%   2.65 x 104 ± 2%   Reaction pathways leading to substitution, addition and oxidation are reviewed. 
