
TY  - JOUR
A1  - Williamson, J 
A1  - Coller, BAW 
T1  - Kinetics, Stoichiometry and Mechanism in the Bromination of Aromatic Heterocycles. VI. Aqueous Bromination of Furan, Pyrrole and Thiophen
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1979
VL  - 32
IS  - 11
SP  - 2423
EP  - 2432
KW  - 
UR  - https://doi.org/10.1071/CH9792423 
N2  - 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. 
ER  -

