Introduction
<P>Aromatic bromination with elemental bromine is one of the most widely used and
extensively studied reagents.
[
1]
Owing to low reactivity, high toxicity, and handling inconvenience, some alternative
brominating agents have been developed. However, a stable, solid reagent is always
preferred, particularly for small-scale reactions that require a specific amount of
brominating reagent. On the other hand, getting regioselective monobromination is
also important, because it is very common to obtain a mixture of monobromides and
dibromides.
[
2]
The commercially available 1,3-dibromo-5,5-dimethylhydantion (DBDMH) meets most
of the requirements mentioned. It is an excellent reagent for the bromination of aromatic
rings, particularly for phenols and polyphenols. It gives excellent yields with a
variety of aromatic rings including protected and unprotected phenol and polyphenol
derivatives, and those that contain carboxylic acids. The reaction is usually faster
and the conditions are mild (at or below room temperature). In addition to the bromination
activity, we found it to be an excellent oxidant for the oxidation of thiols to disulfides
in extremely high yield.</P>
