What do you think about this one?
I've done it but after washing not much was left.
- By 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
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- By lamename69
Alright, thanks a lot. Sometimes I wonder where do people get their "this method has the least impurities" agenda. I doubt that every one of them uses lab analysis...
But then I did that method I linked and the product was allegedly awesome. The cooling might not be necessary as you say though.
But then I did that method I linked and the product was allegedly awesome. The cooling might not be necessary as you say though.
- By TheVacuumGuy
Don't know either. They all have "best" methods, but never share it .
I've wasted 20+kg of precursor before i got it right.
Not to say there is still room for improvement though.
I've wasted 20+kg of precursor before i got it right.
Not to say there is still room for improvement though.
- By 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.
- By Dr. MMX
@lamename69 I can see you didnt get a reply on your thing. Can you please tell us what would you like to know? Of course I had used, it was the 1st thing on the resaearch on the new genre - its always what you should do. Sadly its addiction, not passion. I gain 12-15h experience everyday 
The acetone topic I think it was already explained by William D. I could only add that it really doesnt need to be used for the purification if synthesis is correct, you can do everything " correct" but if you didnt make sure u have "correct" reagents and solvents for it then randomize output goes. I always make. If you inspected my history that much i think you found the (i dont remember now) but over 200g of 300g 2b4m resulting the yield.
Someday addictoin jiust leads to some methhods like this, they are "effective" in the yield, but not in the work. Here usually syntehsis is simple, the guy alraedy had commercial bought as he said so probablyu it was 2 bromo 4 methylopropiophenone, instead of something missed in the ring addictional complications would never happened in the scaled scale becasue it w ould not be worth the effort
maybe.. if 2b4m wopuld be like military would only hunt whole world if somebody has 1 gram... so its so valued to go that path, maybe then
the way the guy did, was very precise he know wyhat he was doing thats why he got that result. You didnt receive it becasue you did a mistake, provide us more details of your syntehsis what went wrong so we can discuss it futher. Without any details we cant tell you anything, we cant even see the question
if i didnt understand that you would like to receive that explaination i am open to tell you, if i can
The acetone topic I think it was already explained by William D. I could only add that it really doesnt need to be used for the purification if synthesis is correct, you can do everything " correct" but if you didnt make sure u have "correct" reagents and solvents for it then randomize output goes. I always make. If you inspected my history that much i think you found the (i dont remember now) but over 200g of 300g 2b4m resulting the yield.
Someday addictoin jiust leads to some methhods like this, they are "effective" in the yield, but not in the work. Here usually syntehsis is simple, the guy alraedy had commercial bought as he said so probablyu it was 2 bromo 4 methylopropiophenone, instead of something missed in the ring
addictional complications would never happened in the scaled scale becasue it w ould not be worth the effort maybe.. if 2b4m wopuld be like military would only hunt whole world if somebody has 1 gram... so its so valued to go that path, maybe then
the way the guy did, was very precise he know wyhat he was doing thats why he got that result. You didnt receive it becasue you did a mistake, provide us more details of your syntehsis what went wrong so we can discuss it futher. Without any details we cant tell you anything, we cant even see the question
if i didnt understand that you would like to receive that explaination i am open to tell you, if i can
- By William D.
You must use dry chemically pure acetone (from the freezer) for washing.
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- By lamename69
There's no acetone in this recipe and that's how I know you didn't read it. Acetone is not the only solvent that can be used for washing. Anyway what's most probable is that washing just eliminated BK-4 so I'm essentially asking whether there might be problems with the reaction itself. Thanks.
- By 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.
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.
- By 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?
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?
- By William D.
To remove excess water from the surface, the product did not deteriorate when drying and in the future. Hydrochlorides absorb water. And some like to pack it in packages. Without washing with acetone or good drying. Then the contents of the package turns into wet snow at best. Carbon chlorides solve impurities well, but it is better not to use it for washing. If you use it for yourself and take care of your own health (we love pure substances).
- By Dr. MMX
there will be difference only in the case if they are there. The most proper way is just to make sure what your using so you will know based on the technique you do what you will face. SOmetimes it can be by "eyes " if something for sure goes bad...
I think H2O is the best solvent for crystalisation, it leads to have avg bigger shards and bigger 1st batch of the yield. In case some discolors are, you can add IPA aclohol to fight it a bit, its usually result of some problems that occured earlier but are shown in the acidification; most likely. DCM is very "weird" solvent and in my opinion its not very good to use it for that reactoin. Usually its "better yield" But rarely it is thing that you would like to have, "washed with acetone, only white left" - dont believe it but consumers don really say it is bad... as looks like
if something for sure goes bad...I think H2O is the best solvent for crystalisation, it leads to have avg bigger shards and bigger 1st batch of the yield. In case some discolors are, you can add IPA aclohol to fight it a bit, its usually result of some problems that occured earlier but are shown in the acidification; most likely. DCM is very "weird" solvent and in my opinion its not very good to use it for that reactoin. Usually its "better yield" But rarely it is thing that you would like to have, "washed with acetone, only white left" - dont believe it
but consumers don really say it is bad... as looks like
- By Dr. MMX
but i would like to prompt my "guess shot" probably partial problem is purity of the final 2b4m as I said in the 1st comment (of your yield and problem of conducting this method) Its the fact it need to be done properly otherwise it cant be saved. Provide us more details. "I did the same" - never happened yet in my life when somebody said that. Its even by the math, you just cant do that, unless its the same line same machine same 1231231 trials before
(of your yield and problem of conducting this method) Its the fact it need to be done properly otherwise it cant be saved. Provide us more details. "I did the same" - never happened yet in my life when somebody said that. Its even by the math, you just cant do that, unless its the same line same machine same 1231231 trials before