Uniqsis has announced an application note that describes a continuous flow methodology for electrophilic bromination.
Electrophilic bromination is a useful reaction in organic synthesis. However, when molecular bromine is used as the electrophile, under acidic conditions, it can be difficult to control both the exothermic addition and to prevent subsequent bis-bromination of the desired monobrominated product.
In application note 21 - the authors demonstrate that using a static mixer chip on a FlowSyn flow chemistry system to control both mixing and temperature - bromination becomes a titration and the reaction can be performed rapidly under elevated temperatures.
The bromination could be performed in a coil reactor however the short reaction time of 30 seconds at 70°C makes it better suited to implementation in a chip.
The authors suggest how the chip based bromination methodology could be straightforwardly scaled to 28g / hour by connecting a 5 ml HT-PTFE coil reactor in line with the mixer chip and increasing the flow rate to 13.2 ml/min.
Typical examples of flow chemistry applications include hydrogenation, nitration, bromination, metalation, molecular rearrangements and synthesis of compounds suchas dihyropyridine, indole, pyrazole, quinolinone and benzimidazole.
To download the application note, please click on the link above.
