Wie wird die 4mmc-Kaltsynthese durchgeführt?

[TheVacuumGuy]

The cold synthesis (some while ago), i do it way different at the moment... more like ( as-hot-as-possible-without-boil) synthesis

 

[animeboro]

How you thing do with dcm and nmp made and then u need use 40min mix ??

 

[TheVacuumGuy]

I don't use both solvents.
There is a post on this forum by @HerrHaber where they do this, as a means of "glue" solvent for the phases. But when you are using a good overhead stirrer you don't have that problem

 

[animeboro]

I know but they get more product in short time

 

[animeboro]

Try use no 300ml dcm but 500ml then u get also more product about ,80% +

 

[animeboro]

your method is one of several cold methods. I started doing it with ethyl acetate in a bottle, I put everything in at once, shake it for 30 minutes and leave it for 1.5 hours until all the 2bromo4methylenopropiophenone is reacted with methylamine and the yield I achieve is the same as yours. but the time spent on the video is appreciated

 

[animeboro]

from what I noticed, the amount of solvent matters, I also use 300ml and my efficiency was lower then

 

[TheVacuumGuy]

This has not so much to do with amount of solvent(s), but whether or not to squeeze some extra from the aqueous layer, which i usually skip. Furthermore on small scale the numbers could be less accurate

 

[Dr. MMX]

btw, its not the best to send direct link wiuth preview on such sites... if youiwanna paste link to youtube make sure it has no preview...

 

[TheVacuumGuy]

Thanks, done.
I actually i dont really care and the vid is "private" bb only takes videos from one of those sites otherwise i hosted it myself.

 

[Dr. MMX]

Its about the youtube which sees where you send the link beacsue of preview
they will probably see that as well without a preview, but for sure a lot of more attention draws when its there

 

[TheVacuumGuy]

Of course they will, with or without preview.

 

[Tovenaar]

Did 50kg on ethylacetate in a hdpe tank with stirrer,

the trick is how to get your temperature under 40 degrees.
2 hours i let the reaction go. Separate, wash, seperate, solvents hcl, filter out product . Then put the remaining liquids in freezer. A few days later take the rest out. Cost me a few hunderd kg bk4 in testing, on top rent workers etc etc….

 

[William D.]

With a large scale, there are problems with ethylacetate hydrolysis. You do the right thing to control the temperature

 

[dnBQByvHb8Zkawbjpx]

Very nice! Would you mind uploading it to BB video library just in case Youtube takes it down later?

At the risk of asking the obvious, in one step you mix the free base with magnesium sulfate - is it implied that you mix it together and filter it immediately through a Buchner funnel, saving the liquid? Or is there any wait time to let the sulfate absorb any remaining water, and can you reuse it after drying (what about other impurities) since 250 g is quite a lot?

 

[TheVacuumGuy]

Well, to be honest, this video is from a year ago, and while it seemed to help somehow (at least in my mind).

Until the moment i found out those were heptahydrate crystals, and did not absorb a single drop . So you can skip that.

This was only to show the "cold" method.

I just finished recording the "now" method, which is so much better that you'd better forget this.

 

[abis777]

It would be nice to share that too. Very nice video anyway

 

[dnBQByvHb8Zkawbjpx]

lmao

please do share your new method, I'd love to see it

 

[lamename69]

What do you think about this one? https://www.reddit.com/r/TheeHive/comments/gngfsa I've done it but after washing not much was left.

 

[William D.]

You must use dry chemically pure acetone (from the freezer) for washing.

 

[William D.]

Acetone is the only solvent that dissolves the product less and dissolves impurities more. We have been working on a better replacement for a long time and there is nothing that works so effectively.
If you do not use acetone, it is better to use crystallization from the aqueous layer. With extraction of impurities with any other suitable solvent.
If you are using real cold synthesis (this thread is about cold synthesis) which can take 1 or 2 days, then it is recommended to use a closed container (under a lid) with the vessel completely filled. This will help to avoid excessive oxidation of the base, which in large quantities can give a brown yellow color and yield losses.

 

[lamename69]

I didn't figure out that you might have read it and still suggest a replacement for washing. Not my lucky year.
I just thought that there is no way that chloroform would dissolve any of the salt, even if it dissolved less of the impurities. So I was worried whether the synthesis was wrong and your answer didn't manage to touch that, but it happens.
So for crystallization, is there a difference in impurity between crystallizing from a 70% water 30% acetone solution rather than crystallizing from 100% water solution and then washing with dry acetone?

 

[TheVacuumGuy]

---

Ice cooling bath for reaction seems no good idea. It should proceed as hot as possible. With icebath temp will not go above 20c.
All in all it seems like a lot of extra work compared to recipes here on the forum and videos

 

[Dr. MMX]

Thats very nice job. I d like to ask 2 questions. Do you wash your glass properly? I suspect as well maybe methylamine quality or incorrect enolization and bromine position resulting problems on 2b4m purity? Usually its 2b4m the main issue of final product

 

[lamename69]

Spill the beans then! Hahah. Did you use a recipe from this forum? I've looked through your profile and it seems to me that you have tried a few of them.