Hi, will epsom salt that i just can buy from regular stores also do the work for me? Also how much is estimated used for this scale of synthesis. Few kg or are we talking couple 100 grams only.
Mephedrone synthesis (4-MMC) in NMP solvent. Large scale.
the production of a few grams and a few kg is a big difference. In my opinion, xylene or dcm is the best for pare kg production, when the entire synthesis when working with the reactor takes 12 hours. every step must be well done, best try small amounts from 100g and then try after some time more and more in a few months you will see for yourself what mistakes you make because an amateur will not do a few kg at once. this is due to various factors in order not to make a mistake because one mistake can cost a lot of time and money.
And should it be higher or lower than those 55-60 degrees? Because in one place someone said that you can add all the m40 at once to the NMP and not worry about the temperature, in another place you were told to keep an eye on not exceeding 60 degrees, and you are now asking if the temperature was higher than 55 degrees.
The conclusion I draw is that we should keep an eye on the temperature when adding the m40 to be in the 55-60 range or below 55, if below 55 then cool the solution as much as possible or would such a range of 50-55 be ideal.
From a table, it appears that when synthesizing 4MMC has NMP for 55-60 degrees, within 20 minutes the reaction efficiency is 98%, but already for 15 minutes at 55-60 degrees it is 71%.
So the best thing would be to add m40 so that the temperature is constantly around 55-60 degrees , and when all the m40 is added and the temperature starts to go down then use external heating to maintain that 55-60 degrees for a round 20 min.
Is it combining well to achieve maximum efficiency for NMP?
The conclusion I draw is that we should keep an eye on the temperature when adding the m40 to be in the 55-60 range or below 55, if below 55 then cool the solution as much as possible or would such a range of 50-55 be ideal.
From a table, it appears that when synthesizing 4MMC has NMP for 55-60 degrees, within 20 minutes the reaction efficiency is 98%, but already for 15 minutes at 55-60 degrees it is 71%.
So the best thing would be to add m40 so that the temperature is constantly around 55-60 degrees , and when all the m40 is added and the temperature starts to go down then use external heating to maintain that 55-60 degrees for a round 20 min.
Is it combining well to achieve maximum efficiency for NMP?
Mr. colleague sorry to mix it up but the translator does not quite translate it well.
1. when adding methylamine, should I make sure the temperature does not exceed 55 or 60 degrees?
2. unless you mean that the temperature should fluctuate between 55-60 degrees when adding methylamine?
Version 1 or 2 is correct to get maximum efficiency.
Question number 3. If the temperature starts to drop below these 55 degrees after I finish adding methylamine, and it has only been, for example, 10 minutes since I started adding methylamine, should I reheat the remaining 10 minutes with an external heat source so that the total reaction time is 20 minutes at 55-60 degrees?
Thank you very much and please answer to each of the 3 questions to avoid bad exchange of information by using non-native language.
1. when adding methylamine, should I make sure the temperature does not exceed 55 or 60 degrees?
2. unless you mean that the temperature should fluctuate between 55-60 degrees when adding methylamine?
Version 1 or 2 is correct to get maximum efficiency.
Question number 3. If the temperature starts to drop below these 55 degrees after I finish adding methylamine, and it has only been, for example, 10 minutes since I started adding methylamine, should I reheat the remaining 10 minutes with an external heat source so that the total reaction time is 20 minutes at 55-60 degrees?
Thank you very much and please answer to each of the 3 questions to avoid bad exchange of information by using non-native language.
I get the purest product in DCM, but the main thing is not to let the solution boil, keep the temperature no higher than 36C (4-mmc turns out to be impeccably clean and snow-white). Another great option is dichloroethane. also a good result is obtained when using NMP and toluene together (3:2 ratio).
I am very interested in your comment. Someone has already mentioned this here on the forum.
I plan to set the temperature rigidly at 34 degrees (half of the given range of 32-36 degrees) and the reaction time at 4h.
The person who gave this information also gave proportions for this reaction.
Namely:
- 100g bk4
- 250ml DCM
- 150ml m40
1. will these proportions of reagents be correct?
2. i am to add 1/2 m40 at the beginning and 1/2 m40 after one hour of reaction. What is the purpose of this? I understand to tame the temperature, but what difference does it make if we do it in 1 go or spread it over two approaches?
I have already had one approach to this attempt. I added everything in the proportions as above. I heated the mixture to 20 degrees and started adding the m40. Unfortunately the temperature did not start to rise on its own. After starting the heating from outside, the temperature suddenly jumped to 40 degrees. The liquid was boiling and turning off the heating did not help.
What I think. Heat the reaction mass to 25-30 degrees before adding the m40 and only start gradually adding the m40 so as not to exceed the mentioned 36 degrees? Is this OK? Or do I heat the whole thing up to the reaction temperature of 34 degrees and only then add the m40?
I have one more question. How do I clean the free base?
Washing the free base twice with an equal volume of 10% sodium trisulphate solution to remove any remaining bromoketone and washing it 2 times with clean water is sufficient? Is it necessary to use something else?
Why is it that when I neutralise with hydrochloric acid in acetone to pH 6, when adding the HCL:acetone mixture to the free base it starts to turn colourful. It's terribly difficult to wash the powder to snow white afterwards.
The colours that have occurred to me are blue, green, dark red and pink.
I plan to set the temperature rigidly at 34 degrees (half of the given range of 32-36 degrees) and the reaction time at 4h.
The person who gave this information also gave proportions for this reaction.
Namely:
- 100g bk4
- 250ml DCM
- 150ml m40
1. will these proportions of reagents be correct?
2. i am to add 1/2 m40 at the beginning and 1/2 m40 after one hour of reaction. What is the purpose of this? I understand to tame the temperature, but what difference does it make if we do it in 1 go or spread it over two approaches?
I have already had one approach to this attempt. I added everything in the proportions as above. I heated the mixture to 20 degrees and started adding the m40. Unfortunately the temperature did not start to rise on its own. After starting the heating from outside, the temperature suddenly jumped to 40 degrees. The liquid was boiling and turning off the heating did not help.
What I think. Heat the reaction mass to 25-30 degrees before adding the m40 and only start gradually adding the m40 so as not to exceed the mentioned 36 degrees? Is this OK? Or do I heat the whole thing up to the reaction temperature of 34 degrees and only then add the m40?
I have one more question. How do I clean the free base?
Washing the free base twice with an equal volume of 10% sodium trisulphate solution to remove any remaining bromoketone and washing it 2 times with clean water is sufficient? Is it necessary to use something else?
Why is it that when I neutralise with hydrochloric acid in acetone to pH 6, when adding the HCL:acetone mixture to the free base it starts to turn colourful. It's terribly difficult to wash the powder to snow white afterwards.
The colours that have occurred to me are blue, green, dark red and pink.
I have made this method few times on low scale (10g bromo) but I have problem with yield (about 25%) and with the "power" of end product (it is not enough strong).
10g 2-bromo-4-methylpropiophenone dissolved in 40mL of NMP, heated to 40 degrees and added dropwise (very slowly to control temperature) 20mL 40% methylamine (while addition of methylamine, the mixture was cooling to not exceed 55 degrees);
Stirring (350rpm) by 20 minutes (while stirring the mixture wasn't heated - temperature has slowly dropped to about 25-30 degrees);
100mL of cold water was added and next 50mL of ethyl acetate (stirred vigorously after addition);
Organic phase was separated, washed 3 times with cold water and dried with MgSO4; cooled to about -5 degrees.
50mL of cooled (-15 degrees) acetone was added;
Acidification was done by ice-cold HCl diluted in acetone (1:5) to the pH=5,7
Freezing by 2-3 hours in -20 degrees and filtered on Büchner funnel/washed with ice-cold acetone.
My questions are:
1) does the temperature of reaction is fine? Should I cool the mixture to not exceed 55 degrees?
2) does the pH= 5,7 is fine? Should I try lower pH to improve the power and yield of end product?
3) what else could I do to improve the yield and power? What I have done improper?
Thank you for any help in this case.
1) no external heating is needed!!! when methylamine is added, the mixture heats up by itself (it does not heat up instantly, while stirring it takes about 5 minutes, and the temperature starts to rise). the main task is to prevent the temperature from rising above 36C. for this, methylamine is added in portions. you can add all the methylamine at once, but then it will be more difficult to control the temperature. 2) your proportions are correct. 3) do not use acetone at the stage of acidification - replace it with ethyl acetate (then there will be no extraneous colors). acetone with acid gives an aldonic condensation reaction - hence the different colors and dirt. 4) the free base does not require further purification if the temperature has not risen above 36°C. it will be very clean. you only need to rinse it 2-3 times with cold water to remove the methylamine residue. thiosulfate is completely unnecessary here.
- By TheVacuumGuy
directly going to try this acidifcation using ethyl acetate. getting sick of playing poker where 2 batches are geenred and 1 perfect white at random.
- By TheVacuumGuy
KING! Tried a small 25g batch, acidified from the bottle by eyeball, so of course too large portion instead of dropwise, but somehow magically it went straight 5.5, so was done in 1 second.
(method used as discussed in this thread, NMP, but replaced benzene for DCM).
(method used as discussed in this thread, NMP, but replaced benzene for DCM).
can you have a closed bottle and stir later when the solution can no longer heat itself then set the water bath to 35 ° c and stir the bottle from time to time for 3 hours ??
no need to close the bottle (vessel). if the temperature is not higher than 36C, then it will not stink much. the main thing is not to let the DCM boil (boiling point 38C) - then the free base will turn out to be pure, and 4-Mmc will be very pure. By the way, about crystallization: I know all the answers, since this is my method
if the solution is no longer heated, and its temperature has begun to decrease, then the reaction is complete - proceed to the next stage. the average reaction time from the start of self-heating to the temperature decrease is from 2.5 to 3.5 hours (depending on the volume of initial reagents). that is, if the temperature itself began to decrease, then the reaction is over. everything is very simple
- By TheVacuumGuy
strange, i've monitored temperature closely a couple of batches (every 5 minutes), and it shows that temperature will decrease after ~55 min while still have amine remaining to add. when adding this remainder all at once, the temperature does nothing, it will keep decreasing.. this would indicate reaction complete, but why such a difference 2.5/3.0 hours vs 55 min?