4′-Methylpropiophenone bromination to 2-bromo-4'-methylpropiophenone. Large scale.

[ADATA]

The 2B4M produced in this way has a lot of impurities. I'm not sure what it is, the follow doesn't work

 

[whitelabel]

Would the PTSA and nbs method work much better?

 

[Lev]

Bromdioxolane 98%

 

[w2x3f5]

new replacement 2b4m, obtained by conducting a halogenation reaction in a solution of ethylene glycol, standard protecting group for ketone

 

[whitelabel]

Care to elaborate on this method?

 

[Nimrod001001]

Hi friends I would like to have some of your help
I used 50g 4mp, 40ml Hbr, 15ml hydrogen peroxide 35%
this my second run after previous attempt its been to much bromine and I had green look like crystals
So I used less hydrogen peroxide
My mr stirring already for long time like 20 hours
And looks still oily and separate
Wonder why its not crystalize like in the video

 

[William D.]

This is not always crystallizes the same even under the same conditions. It depends on the temperature. According to your description, not the entire propiophenone reacted. This does not look bad, but add the amount of acid and control the addition of peroxide by the visual method (until the bromine reacts).

 

[Nimrod001001]

Thanks for replying friend in the end I had I finish but yield was low and the mmc4 yield also I think try on doing mmc with bromine instead of Hbr

 

[Dr. MMX]

Please be careful when handling Bromine in its elemental form. Do read about handling it before

 

[Nimrod001001]

Yes I take handling with bromine very seriously its not a joke hope post on high yield

 

[William D.]

It shouldn't make much of a difference in the yield. You did something incorrectly.