[Parathormon]

Hello everyone,

I have some question regarding to aforementioned reaction - as of my experience procedure copy from HBr/H2O2 where man use 1eq carbonyl, 1.1eq HBr and 1.4eq H2O2 but using HCl instead do not lead to full conversion.


As of my TLC for such procedure using HBr I received 100% conversion and selectivity to monobrominated product.

While using HCl I received mostly monobrominated product, some significant part of substrate and little trace of something more unpolar (dibromo derivative?)



As of my literature research it can happen due to slow reaction between h2o2 and HCl and even below 30% conc of hcl chlorine is not appearing at all, instead of this HCl is slowly decomposing H2O2 to oxygen and water.


Question to You - is it possible to somehow challenge this problem and use this procedure or it is rather not recommended? I also didnt find any work or patent on such reaction (monochlorination of carbonyls by h2o2/hcl).

[Hunter2]

While using HCl I received mostly monobrominated product, some significant part of substrate and little trace of something more unpolar (dibromo derivative?)

You mean monochloriated product, do you?

Which Carbonyl reactant do you use.

[rolnor]

It seems natural to try a larger excess H2O2 and HCl? Do it in the cold.