Generally for the bromination of acetanilide, sodium bromate+HBr in AcOH method is preferred because of in-situ generation of bromine and thus handling of small to larger scale reactions. Can the presence of HBr hydrolyze the acetamido group and thus create complications for getting clean 4-bromoacetanilide?
It should not creat too much trouble. I did publish the synthesis of 4-bromo-2-methylphenyl-butanamide by quite similiar method. I exchanged sodium bromate by H2O2 for cost reasons but did not have any problems with hydrolysis (see example 5 US2003065211 (A1)).
What is the role of H2O2 as in the method neat Br2 has been used. There is no issue of in-situ generation of bromine.
The method I have discussed, is different (sodium bromate+HBr in AcOH to generate Br2)
If there is no water present, hydrolysis would seem to be unlikely. You could add a small percentage of acetic anhydride to suppress any hydrolysis that does occur.
We used H2O2 to oxidize the resulting HBr from bromination to make full use of bromine. Use can use HBr as well, but will have water in the system then and some chance for hydrolysis
There is no hydrolysisof amide unless you heat the reaction mixture.
- Badges
- Science topic
- Similar topics
- Chemistry
- Organic Chemistry