Verbesserte Synthese von 4MMC

[Dr. MMX]

How are you sure thats 4mmc tahts 85% by grams of 2b4m?

 

[HerrHaber]

calcuilating the percentage yield was done on the basis of comparing the moles of isolated product with the amount of moles that could have been only theoretically obtained

 

[HerrHaber]

Absolutely agreed, what I know from personal experience is that colours are influenced by purity and nature of the antisolvent used to precipitate it, like acetone in this case. I should try this one again but precipitate separate portions of the freebase solutions with different antisolvents Et2O, petroleum ether 40-60, analytical grade Acetone as well as the technical one I have now and recovered acetone batches of different purity.

 

[Dr. MMX]

I believe that the true key is purity of acetone used for acidification. I have noticed very huge differences when performing synethsis on DCM. For other solvent it didnt matter that it was not pure (i mean it was 99% from store anyways but its not maximum that can be). Best yield in pure crystals I did 64% but only once such score. For intereting things, the color of powder before separation was a little brown and like 20 ml of acetone was enough to get it off from like 200g 2b4m batch. Very interesting. Thats why I wonder what would be your yield in pure form

 

[Dr. MMX]

99% product and its liquid left at 28c. Powder was in most of that youi could crush with a little push, besides that it needed glass rod to push it it so it was little darker - uits the reason liquid couldnt be decrashed to 1c to get more of that

 

[Dr. MMX]

 

[BuryVatorynov]

Bro how much gram mmc u get this method ??

 

[HerrHaber]

Sad to tell you that my current location can't afford me to go big on batches so I do many small ones to gain data that I also enrich with what you and other practitioners say and attention to the precipitation conditions were observed and confirmed by other members. It would be constructive to have this differential precipitation experiment posted here as a new thread but I'm in no condition to make a big batch (4L reactor available but not for this reaction in this small place). But I may be brave enough to go for quarter Kg if challenged when intoxicated. That's why my usual purchase is about 100g bromoketone usually. And that is portioned up to 100 milimoles (22,8 or something like this g) but often enough smaller for R&D and first of all educational purposes. Cheers!

 

[TheVacuumGuy]

I use anhydrous acetone, and it's not of any noticable influence , besides the wallet.

Oh, and it smells much nicer somehow (the acetone)

 

[Dr. MMX]

after separation the 2nd liquid i have received about 58% of such purity crystals. Probasbly about 2-3% are still there. so from 240g mmc powder of 300g 2b4m its about 180 g of crystal pure product.

 

[HerrHaber]

antisolvent (acetone, Et2O, hexanes) has a great impact on the purity and color of the crude product you should practice until the crude powder is most consistently off-white or white.

 

[TheVacuumGuy]

yes, but it doesn't matter all that much whether you use 98, 99, or 99.97% acetone, except for the price difference of the latter

 

[Dr. MMX]

honestly I have used acetone that i ditill but i forget the filter that blocks water and i used acetone with water = still product was pure

 

[Dr. MMX]

the purity in shops is just a lie alwayys distill it NO MATTER WHAT
they are using techniques to get like 10% more or something... i ve heard its enough to put in sunny pacec in warehouse and change it to cold and over and its many more to get more product, when already they have proofs and technical data of 99% purity etc
always distill is my 1st rule

 

[Dr. MMX]

My 2nd rule is: distillation 24/7 it just happens that i have mounted aparature for whole day... thinking about another one just all the time I am missing solents, yet its distilling all the day... i suggest just finding place on table and do this

 

[TheVacuumGuy]

that is something on my todo list as well. using new solvents every time is becoming quite expensive too

 

[Dr. MMX]

I do have 234 grams in DCM

300g 2b4m 900ml dcm
460 ml methylamine
nahco3 5% 500 h2o
1500 h2o

1100 acetone for acidification
200 acetone for purification

i did synethsis on roundbottom flask. basicly the methylamine on that batch can be probably be poured all at once, but with good "road" a thin layer on the wall.


I was recording a video of this job but it was just standard procedure, nothing abnormal
I mean i need to distill acetone for acidification otherwise it leads to discolors.
after filtratoin it was a little yellow solution.
pic 1 before fitlration
pic 2 the color of wastes - perfect for distilation of acetone
pic 3 color of solid after sucking out liquid

 

[Dr. MMX]

if need some more photos please ask i got 3 hours material

 

[TheVacuumGuy]

i usually use a plastic box (like the curver's) , i put it on the hotplate, and the flask goes in the box. As soon as i notice it might start boiling, ill throw in a layer of water.

but the plate's display is broken, and the other day the thing was way too hot, so i threw in a few liters of water and it went straight through, over the hotplate, over the floor , over electric wiring. So make sure it is not >100c

 

[Dr. MMX]

I have 2 beakers, both in boling solvent, then I add powder. in the end of adding powder usually its calculated to add some boiling solvent, and in th epreceise mooment of add ing all its moved into 100c oven inside hot water bath