Hello,
here is my report about an
amphetamine synthesis, which unfortunately did not go very well due to the yield at the end.
First of all about me, I recently came across this forum and had already had a little experience with
amphetamine synthesis.
But here I found someone I could ask all kinds of questions and who also gave me the courage to publish my report here. Mr. G.Patton was a great help to me, he always has an open ear and answers every question, no matter how stupid it may be.
I did not describe every step exactly, because for this the instructions in the forum are much better, I took a lot of photos and mostly just highlighted the differences to the instructions.
I'll briefly give my stakes for the synthesis and then we'll start directly. For the A/B extraction and the subsequent acetone wash I don't give any details here, either in the report below or take from the instructions here in the forum.
Stakes:
IPA: 2x 250ml
Acetic acid: 2x 125ml
Water: 2x 50ml
P2NP: 50g (5g+45g)
Alu: 60g
NaOH/Water: 250g/250ml
Mercury(II) nitrate: 0.5g
I have driven 3 syntheses, this one with the next photos was the last one.
The amalgamation was started with about 2 liters of water, aluminum and mercury salt.
It took over 40 minutes until the reaction was ready, quite violent reaction, I have never waited so long.
I took a picture almost every 5 minutes after I put the mercury salt in and kept shaking it in between. You can see very well the different phases including the peak of the reaction and the subsequent decay. From minute 25 the temperature slowly went up and reached the maximum temperature of 70°C from minute 35.
After drained the water i do not rinsed the aluminium.
I make 2 solutions by halving the input amounts of the liquids, one with 10% of P2NP and one with 90% of P2NP. The one with the 10% goes directly into the flask to start the reduction. The one with 90% I let run slowly through a funnel, I use an overhead stirrer, and watch the temperature. This time, however, the reduction had to be kicked off with a little mercury salt. I also did this again at the end, about 1 hour later.
I usually filter the reaction mass before adding caustic soda, because I use a separating funnel afterwards to separate the phases. (no photos)
I dry this phase over MgSO4 overnight and then salt out.
I always collect all liquids before I recycle or reprocess them. When I tipped the isopropanol together after vacuum filtering, I noticed that something settled at the bottom of the beaker. I measured the pH value of all 3 tipped together filtrates, which was approx. 6.5.
And I thought, I will add sulfuric acid and filter again, but first I put it in the freezer and see what happens.
What I got to see after about 3 hours was amazing (photo), I titrated the "waste" solution down to about pH6.0 with additional 7ml 1:5 H2SO4:IPA solution and filtered, the yield was the largest optical of the 4.
I will only use the scale always at the end, when the product is consumable, all other is waste what don't care.
So now I have 4 yields instead of 3. If I didn't care, from now on I would also throw everything together and determine a total yield.
So far, it looks like the first synthesis was a lucky strike, because it was done without complete amalgamation.
Also that my first synthesis is the cleanest shows that my way to filter the reaction mixture after the reduction is the right way. All the others look so dirty and disgusting, no one needs that.
For the second synthesis, I waited about 40 minutes for amalgamation, but then I made a mistake. When I changed the round bottom flask and the 90% P2NP solution slowly ran in, the reduction did not start. I hesitated too long or waited until I decided to add mercury salt again. I saw it too late that the funnel was already 2/3 empty, I should have acted before, so now I had a large reaction mass in the flask, which could become a problem for me, if I am not careful. I provided cooling and fetched something to catch for the hot soup that could shoot out of the top of the reflux cooler.
And so it happened, the reaction was not to tame despite cooling, it went through cooler and splashed out the top, by a beaker what I put over the top was the worst prevented, I had to make then only some cleaning. Have I once again lucky.
Here, too, I performed a filtration after the reduction before I made the alkalinization. I think the discoloration was caused by the strong reaction, also the smallest yield we saw here.
Third synthesis, 40 minutes amalgamation, addition of mercury salt to start the reduction, but this time only with the 10% in the round bottom flask, I left the funnel closed this time. After the start, with cooling and feeding with solution, I regulated the temperature to 60°C-70°C and towards the end I started the reduction again with mercury salt, which was also successful.
This time alkalinization was done before filtering, but filtering didn't help much, I had to fill this gray soup in my separating funnel for phase separation.
These were the three preliminary stories, each a little different from the other, but still decisive in the result. Now the pictures of the salting and the chance find of the fourth yield.
Still briefly to the pictures:
You will see an electric pH meter with glass body and probe, which I use for titration. Since some assume that you can't properly determine pH with such a device, when there is no water in the solution, I used an analog way for comparison. I do not do that normally, I trust the device because I tested it, the pH determination is perfect, in my opinion, there is nothing more convenient in the titration by using such a device.
The four first yields after first salting.
I dried the four yields and then ground them with a grinder.
Now I dissolved the salt in water under a little heating, then filtered off the solids and brought the solution to below pH6 with a drop of hydrochloric acid.
Then the solution was washed/shaken out 3 times with 30ml,20ml and 10ml of petroleum ether respectively the solution was then separated using a separating funnel. The petroleum ether was discarded. After washing out the non-polar impurities, the solution was then brought to a pH greater than 13 with sodium hydroxide. And again, the solution was then washed/shaken out three times with 60ml, 40ml and 20ml of petroleum ether, respectively, and then separated with a separating funnel, by the addition of NaCl.
MgSO4 was then added to the separated petroleum ether and placed in the freezer for 3 hours, then the MgSO4 was filtered off and the petroleum ether was evaporated using temperature control on a hot plate at 40°C.
The pure amphetamine oil is poured into a beaker which is filled with isopropanol. Then, as before, it is salted out by titration, filtered and dried. I always used a heat lamp for drying before I had a desiccator, which works very well and also goes relatively quickly.
Finally an acetone wash is done, for this I use a grinder and sieves to get the sulfate as fine as possible to get the surface as large as possible for good cleaning.
Again, the lamp was taken, the lamp should be hung so high that the product does not get much warmer than 60°C.
Yes and unfortunately my very poor result of 18.5g, that is only 33% of 70%. Not even half of what is usual.
This is just frustrating. I just don't know what I'm doing wrong here that I'm so bad.
After this result I did not make the other 3 separately any more but threw them together, resulting in a total of about 20g. All in all not very much, but very clean product.
I am open to any suggestions.
