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.

 

[kikoliko]

If someone made 10l batch of 4mp 7650ml of hbr and he dropped 3 liter h2o2 he stirred for 16 hours and left with liquid little liquid is reactor, should he add regents or just blanced pH water and fiter it because its really nice batch but i guss the proportion where not good

 

[Dr. MMX]

I have seen the case when h2o2 was overdosed, some mistake was done during setuping the reactor and bromine was already released earlier, so it was not possible to calculate the correct amount that could be added it so it was just added that much to receive solid form of substance from the liquid. . Not a lot I can tell, for sure it will be someting other that we receive than 2b4m, but the final mmc product was just little different - opinions of the testers. During synthesis there was no troubles but it was just experiment on hundred grams scale.

 

[whitelabel]

Hi, me again

Question...
If done right, is the bk4 produced by this method of good quality as compared with the precursor 2b4m being sold by suppliers??
..guessing it might be even better.

What's the best way to purify obtained bk4 after this procedure to get purer and stronger 4mmc?

Thanks in advance guys.

 

[kikoliko]

You can recrystallised it ,in solvent like toulene or dcm , i ask the gemini recpie for recrystallised bromo and he elaborate since is not controlled substance

 

[whitelabel]

What is the procedure to recrystallize with DCM.