Sit back, my dear reader, and be patient for a fascinating story about how to make everyone's favorite 4 mmc.
Let's figure out what and how in moles will be to our favorite reagents and reactions. So, what we know about them, and what we get (check the calculations yourself).
Thus, 1 mole of 4-MPH is 148.2 grams, taking into account the concentration of 148.2/99% = 149.7 grams, or taking into account the density = 155.5 ml.
Thus, 1 mole of HBr=80.91 grams, or taking into account the concentration of 168.5 grams of 48% aqueous solution, or taking into account the density of 112.5 ml
Thus, 1 mole of MA in 38% solution would be 82 grams of 38% solution, or 91 ml taking into account the density.
Thus 1 mole of HCl in 36% solution would be 101.3 grams of 36% solution, or taking into account the density of 86 ml.
If HCl is dissolved in IPS (hydrochloric acid IPS, 30% solution) or dioxane (hydrochloric acid dioxane 26% solution), we have:
- 1 mole HCl in IPS = 121.5 grams
- 1 mole of HCl in dioxane = 140.2 grams.
I apologize to the chemists for such a sloppy spelling.
You can calculate the formula and molar mass of iodine ketone by yourself, taking into account that instead of bromine (Br, molar weight 79.91) there is iodine (I, molar weight 126.9). This also explains why it takes more iodo ketone than bromo ketone to make the same amount of mephedrone: it is heavier per molecule.
This prescription uses minimal but professional equipment. Flasks, tubes, transitions. I have a bad attitude towards "pot" syntheses, because it is fundamentally impossible to achieve normal yields and quality in them.
I'm not against the free distribution of this script, but I'd like to be referred to and liked. However, there are no obligatory actions here either, everything is up to you.
Reaction formulas (here two reactions go in parallel, a part of the result of the second reaction is returned as a starting reagent for the first one):
- 2HBr+H2O2=Br2+2H2O and
- C10H12O+Br2= C10H11OBr+HBr
TOTAL REACTION: C10H12O+HBr+H2O2= C10H11OBr+2H2O
Reaction result - Bromketon-4, BK-4, C10H11OBr
1.2 Washing after bromination.
Necessary to remove residual bromine and acid from the resulting bk-4.
1.3 Amination of BK-4 with methylamine to yield mephedrone
Reaction formula:
- C10H11Br+2СH5N=C11H15NO+HBr*CH5N
Reaction result - Free base of mephedrone (oil, freebase), C11H15NO
1.4 Washing after amination.
Necessary to remove residual methylamine (MMA) and from the resulting mephedrone
1.5 Acidification with hydrochloric acid (aqueous hydrogen chloride solution) with release of aqueous solution of 4-MMS
Reaction formula - C11H15NO+HCl=C11H15NO*HCl
Reaction result - mephedrone hydrochloride, C11H15NO*HCl
1.6 Washing after acidification.
Necessary in order to clean the aqueous solution of HC 4-MMS (mef) from the organic-soluble dirt.
This step only makes sense if you have chosen among the acidification methods Acidification to the aqueous fraction, and it can in principle be considered as the beginning of cleaning. But since it is carried out on the reactor as part of the same loading and the same procedures, I mention it as one part of the synthesis.
Reagent calculations for 30 moles:
4-mpf (the main precursor for making mephedrone):
----- 30 moles of 4-mpf is 4,491 grams or 4,536 ml. We take into account here the concentration (99%) and density (99%) of 4-mpf
TOTAL is 4,491 grams or 4,536 ml.
HBr (Hydrogen Bromide Acid - aqueous solution):
----- 30 moles of Hbr (that's 2,428 g pure or 5,060 g 48% solution, or 3,395 ml) PLUS 5% stock
TOTAL of Hbr is 5,310 grams, or 3,570 ml
Hydrogen peroxide (we recommend taking a concentration no higher than 37%, higher concentrations are a fire hazard):
----- 30 moles of H2O2 (that's 1,020 g pure or 2,756 g 37% solution or 2,418 ml) PLUS a 10% reserve
TOTAL 37% PERKISSION - 3,033 grams or 2,660 ml
If you bought a different concentration of peroxide, you can easily (using the information in the article "Molar Calculus for Dummies") recalculate to the amount you need.
The maximum possible theoretical yield from this step is 20 moles, or 4,542 grams of BK-4.
Estimated yield including losses on synthesis and washes - 93% - 28 moles or 6 360g of BK-4
For decolorization and removal of acidity you need (minimum)
- Sodium sulfite 20% solution - 400 ml, i.e. approximately 80 grams of sodium sulfite dissolved in 320 ml of water.
- Sodium baking soda 6% puree - 1,400 ml, i.e. approximately 230 grams of soda dissolved in 1,170 ml of water.
BUT: this is if you have properly drained the aqueous layer without leaving any significant residual water (with bromine and acid). Therefore, we advise you to make twice or maybe THREE times as much of these reagents, and add in small portions - sodium sulfite - until the PM discolors, and soda - until the Psch is at least 6-7. In this case reagents may go more - it happens.
After these operations we add the solvent - in this case ortho-xylene in the amount of
----- 250 ml/mol*30 moles = 7,500 ml or, taking into account its density of 0.88 = 6,600 g.
Calculation of reagents for 28 moles:
BK-4 (output from BROMING):
----- 6,360 g. BK-4
TOTAL: 6 360 grams
Solvent (poured in at the previous step - washing).
----- o-xylene, the solvent in which BK-4 was dissolved after washing in the previous stage.
TOTAL: 6,600 grams or 7,500 ml
Methylamine (MonoMethylamine, MMA).
----- NOTE. The stage requires TWO moles of MMA per 1 mole of BK-4, plus a reserve of 1.4. So you get 2*1.4*28=78.4 moles of MMA, or 2437 grams pure. Make sure your aqueous solution of MMA is not exhausted and matches the concentration, or take a larger stock(!)
TOTAL: 6,400 grams of 38% aqueous solution, or 7,030 ml.
Maximum theoretical yield is 28 moles or 4,960 grams of mephedrone.
Planned yield including losses on synthesis and washes - 78.5% - 22 moles or 3,900 grams of mephedrone.
Distilled water is used to flush the oil in the solvent. One portion of flushing is about 1/10 of RM volume, i.e. 1 400-1500 ml
TOTAL: Distilled water in the amount of 1400 ml*Number of washes. There can be from 3 to 6 flushes. We recommend stocking up on 10 liters of water just in case.
In addition, 2 portions of solvent (o-xylene) about 500 ml each will be needed for oil extraction from the drained water layer.
TOTAL: 1000 ml of o-xylene to extract the oil from the aqueous layer.
Calculation of reagents for 22 moles:
Mephedrone (Freebase 4-MMC, "oil"):
----- 3,900 grams (yield from the AMINING step)
TOTAL: 3,900 grams
SOLUTION (Ortoxylol, O-xylol):
7,500 ml poured into the 1.2. - washing after the BROMING step. PLUS 1000 ml used to extract the "oil" in step 3.4. - washing after the AMINING step)
TOTAL: 8,500 ml
Further the set of reagents differs depending on the acidification method you choose.
For anhydrous acidification (for vessels that do not have a bottom drain):
Hydrochloric acid IPS (hydrogen chloride gas solution in isopropyl alcohol):
----- 22 moles of HCl is 801 g of pure hydrogen chloride, or 2,670 g. 30% solution in IPS, or 2,500 ml of solution.
TOTAL is 1,670 grams of 30% HCl solution in IPS, or 2,500 ml.
For acidification into the aqueous fraction (for reactors):
Hydrochloric acid (hydrogen chloride gas solution in water):
----- 22 moles of HCl is 801 g of pure hydrogen chloride, or 2,225 g. 36% aqueous solution, or 1,885 ml of solution.
TOTAL is 2,225 grams of 36% aqueous solution, or 1,885 ml.
Distilled water: to ensure solubility of ALL GC MMA in water, it is recommended to pour approximately 2.5 times more water than the hydrochloric acid used.
TOTAL 4 700 ml distilled water
The maximum theoretical yield is 4,700 g. GC of mephedrone.
Planned yield including washes -- 95% -- is 21 mol or 4,488 grams.
DXM is used to wash the aqueous fraction in solvent. Washing is done after draining of the organic layer. One portion of washing is approximately 1/10 of the volume of the remaining aqueous fraction, PM, i.e. 1,100 ml. Usually 2-3 washes are enough.
TOTAL: DXM in an amount of 1 100 ml*Number of washes.
1.1 Preparation.
The reactor (reaction vessel) is filled with 4-mpf and Hbr in the indicated amounts (completely). Hydrogen peroxide is poured into a dropping funnel (or any other feeding device, such as a metering pump). All reagents are at room temperature. The cooling/heating system of the reactor is set to cool the RM for the first 15-20 minutes, so that as much peroxide as possible can be poured during this time. However, after 10 minutes of reaction, the temperature in the RM should exceed 70-75 degrees. If you can't do that, you will have to heat the RM much more than 1/3 of the peroxide, and the whole reaction will go half as slow. The yield may also be less. All the reaction should preferably be carried out in the temperature range of 70-85 degrees Celsius, and be prepared after 15-20 minutes of reaction on the contrary, start heating RM, so that the temperature in the RM has not fallen below 70 (preferably 75) degrees. Since the heat until about 1/2 of the peroxide will be released actively, the temperature of the heating fluid is put at about 60 degrees, then raised to 70-75 degrees.
!!! Important-1: In contrast to many prescriptions, the high reaction temperature is useful and greatly accelerates the passage of this stage and does not affect the purity of the product. But the presence of UV rays is harmful for the reaction - by-products are formed. Therefore, it is advisable to completely remove natural light, turn off all light sources (including fluorescent and LED), and the reaction should be carried out in yellow light (halogen, incandescent, LED lamps with a color temperature of 2500-3000K). Ideally, purchase and turn on special UV-free lamps (yellow light). Since this light is unlikely to be sufficient, have a portable lamp (preferably yellow too) to illuminate the part of the reactor you want to see what state your RM is in.
!!! Important-2: There is no time limit on the reaction. No byproducts will form if you make it longer. So, for example, if you get into the temperature range of 75-85 degrees, the entire reaction will complete in about 1:00 - 1:15 time, but if the temperature stays below 70 degrees, you may need 3:00 - 3:30 time, or more (up to 4:30)
!!!Important-3: Two reactions run in parallel in the bromination process, and each is accompanied by a release of heat.
- 2HBr+H2O2=Br2+2H2O and
- C10H12O+Br2= C10H11OBr+HBr
It is assumed that almost all of the heat is released in the first reaction, but this is not true-they are both approximately equally exothermic. Each of the reactions has its own distinctive feature - the first reaction releases molecular bromine, which colors the PM yellow-orange-red-dark maroon. The second reaction, on the contrary, bleaches PM (fully or partially) and releases gaseous HBr - i.e. the same BVK, which is mostly absorbed by PM, but may escape (not have time to be absorbed) through your absorption cascades as caustic acid gas.
At the beginning of the synthesis, they proceed at about the same rate, or even a second faster. However, after about half of the 4mpf has been reacted, the second reaction slows down and the RM becomes permanently stained, in greater or lesser shades of red. The second reaction is also autocatalytic, or, simply put, maintains itself, that is, it occurs in "bursts," resulting in a strong release of HBr, and the RM becomes strongly discolored. This course of the reaction is normal and should not be feared, but the droppers inserted into the reactor and the RETURN COOLER should be secured so that they are not knocked out by an increase in pressure. In addition, the start of the next "burst" of the second reaction can be provoked, for example, by stopping stirring for 2-3 minutes, or a sharp change in stirrer speed, not to accumulate products of the first reaction and let the second go more often with less reagents, which will make your reaction calmer. Also, in the second half of the synthesis, HBr, which is formed in the second reaction, may be needed to keep it going. Therefore, if the PM is very red, you should stop pinning down the peroxide (which in the absence of free HBr in the second half of the synthesis may just decompose and not go to the right thing) and turn off the stirring for 2-3 minutes to let the second part of the reaction "start".
In the second half of the synthesis, for the reasons described above, the PM stops discoloring, acquiring a red hue. Here we carefully watch the color of RM, if a dark red/burgundy hue appears, as well as reddish vapors coming out of the reactor, we understand that we have a large excess of bromine, and therefore probably a lack of HBr (which will appear again after the passage of the second reaction). And this means - we need to stop the peroxide addition (it can decompose in vain) and try to "provoke" the beginning of the second reaction by stopping the stirrer for 2-3 minutes (to zero) and then abruptly changing its rotation speed by any number of revolutions, from 0 to maximum. These measures should be enough to make your PM start to decolorize, and the HBr not retained in the RM went through the cascades (we remember that there is a reserve). However, the RM will not decolorize to white as in the beginning of the synthesis, and once you achieve a light orange color, the peroxide addition must be resumed. This will happen several times (depending on the depth of discoloration), and the dark red color will build up faster, and the discoloration will happen less often, and with more "provocations". Before the last 10-15% of the peroxide is added, you should try to maximize bleaching. The temperature at this point will no longer rise by more than 3-4 degrees, and the temperature of the heating fluid in the jacket should not be below 70 degrees, to avoid crystallization of bk-4. In general, if you keep the temperature within 75-85 degrees, this stage is reached in about 40-50 minutes, at temperatures below that, it may take up to 3 hours. But if you're caught in a decrease in RM temperature below 70 degrees, or even more so, the crystallization of bk-4, you need to focus as much effort as possible on warming up the RM. At this stage, you are likely to have HBr bubbling in the cascades anyway, and if the "t" is over 75 and bubbling, the peroxide addition should be suspended for a while (until the bubbling is over).
Then you pour in the remaining 10-15% peroxide at a fast pace, and stir the PM for another 10-15 minutes. It won't discolor much anymore, and the excess HBr will be bubbling in your cascades. If the reaction was carried out quite well, the excess peroxide will bubble in the cascades - its bubbling differs from HBr in that it does not coincide in time with decolorization (HBr release coincides), and is equal in the first and second vials of the cascade (HBr, due to its absorption by soda or alkali, has less bubbling in the second vial). In any case, you pour out all the peroxide, and the stock of HBr and peroxide should be enough for you to get all the 4-mpf pro-rominated. After that, you try to brominate the rest of 4-mpf in your PM by the above described "provocations", several times, spending 15 minutes, as an alternative - leave the RM with the mixer off for half an hour, not forgetting to heat, then sharply turn the mixer to the maximum rpm. Bromination of residual 4-mpf will be visually seen as "flowers" or "salutes" rising from the depths of the RM, accompanied by bubbles - very well seen on the surface of the RM when the stirrer is stopped - they appear in 1-2 minutes after stopping. When after several provocations, such traces stop appearing, your 4-mpf has reacted.
Take your time the first few times, remember that procrastinating reaction time, especially if you haven't reached the right temperature, will not ruin your product. And it's better to spend both 3 and 4 hours to get the maximum yield. You can tweak the optimal time and temperature later. So if there are any problems (not discolored in time, for example) just increase the time, remembering to heat the PM to the right temperature. To look at the condition and color of the RM you need a portable lamp on a long cord (I usually look at the top of the RM and the "tail" (bottom drain) of the reactor). The bottom drain, due to the fact that it is outside the jacket, usually by 2/3 of the synthesis time is clogged with solid precipitated bk - there is nothing you can do about it, it will then be dissolved at the next stage. Often also solid BK falls out on the lid and on top of the reactor walls (from inside, of course) - the jacket does not reach there as well - this too will go to dissolution later.
So, bromination of 4-mpf is finished, provocations do not give visible bubbles, so bromination is finished. The temperature of RM is kept only by the jacket and it goes down to 68-70 degrees. We reduce the temperature of the jacket (heating tank) to 60 degrees and immediately proceed to the neutralization and rinsing of the RM.
Washing of RM after bromination.
As I said before, it is possible (and desirable) to wash immediately after bromination, not allowing RM to cool below the crystallization temperature of bk-4, in order not to warm it up painfully and for a long time afterwards. I'm serious - first of all, the temperature difference between the center and the edges of the reactor can be quite large, which will complicate the melting of bk-4, and secondly - the solvent can be poured only after the RM decolorization by sodium thiosulfate.
Important. The solvent (in our case ortho-xylene) must be poured only after decolorization of RM, because it itself is well brominated by bromine, which remained in our RM, thereby giving a by-product. So we bleach the PM first. For this purpose you have to have in a small dropping funnel (250-500 ml) diluted 10% solution of sodium thiosulfate (30 grams of thiosulfate per 270 grams of water or 50 grams per 450 ml of water). If the funnel is 250 ml, you can make a stronger solution, or refill it as you go. Depending on different parameters (quality of your HBr, presence of bromine, speed of reaction, etc. - you may need from 200 to 400 ml of solution). The thiosulfate solution spoils in the air, not quickly but surely, so it is more correct to make it right before the reaction.
So, you put a small dropping funnel with the solution and turn on a good stirring (we have about 450 rpm) and start pouring the solution. You can pour the first 100-150 ml as quickly as possible, then add 20-50 ml as needed, depending on the color of the RM. Keep in mind that bleaching is not instantaneous, it takes several minutes. Your RM begins to bleach, through yellow to white. If you did the reaction correctly, a milky white RM color is achieved. Actually, when this color is reached, the infusion of the thiosulfate solution can be stopped, the white color is the only criterion for the sufficiency of the infusion. If you performed the reaction with a side effect (in the light, for example), the RM will remain yellowish in color. Then the infusion should be stopped if the color does not change after another 20-30 ml infusion. If you have residuals of bk-4 frozen somewhere in RM with a color other than white (e.g., orange), you can have an "extra" 50 ml after stopping the decolorization so that after adding solvent and dissolving these pieces, the thiosulfate will "intercept" this bromine as well. In general, a small excess of thiosulfate will not harm your RM.
The temperature of your RM by pouring thiosulfate solution at room temperature and stirring will drop to about 60-65 degrees, you can't go lower than that, you have to warm it up with a jacket. And it's time to pour the solvent, preferably also measured in advance. In general, it is better to measure and pour all reagents for the synthesis into flasks/canisters (preferably with a spout) at once so as not to waste time on this work during the synthesis.
Then we pour in the necessary amount of ortho-xylene and stir. Our RM becomes white and turbid when stirred, as the temperature drops. However, dissolution is going on, and if during this dissolution your RM turns yellow again (i.e. somewhere unaccounted bromine came out), you can add more thiosulfate solution. According to my experience, longest dissolves "tail" of reactor (bottom drain), which we have outside the heating zone, but it dissolves in 15-20 minutes, it needs to provide good stirring and temperature of RM at least 50-55 degrees (heating, if necessary by jacket) - and this "tail" will melt by "funnel" of water and solvent, by flow, which will provide stirrer. As a last resort, such "dead" zones can be heated with a construction dryer, but not exposing it to temperatures over 150 degrees, so that the glass does not crack. bk-4, stuck on the top of the reactor walls and on the lid (from inside) is washed off by a sharp change in speed of the mixer, which creates waves and splashes of solvent. Our reactor is filled high enough, so these waves and splashes will wash away the solidified bk-4.
When dissolution is complete and there is no solid bk-4 left in the bottom drain and other corners of the reactor, the agitator is turned off and the layers are split. The top layer you should have is bk-4 dissolved in xylene, it should be about 15,5-16 liters. The bottom layer is water with the impurities removed - about 4 liters or a little more (if you used 37% peroxide. The bottom layer is drained into the waste, and only then is the acid neutralized (since most of the acid goes into the aqueous layer, and we save a lot of soda and traffic). The heating of the reactor jacket can be turned off, as we will need a RM temperature of about 35 degrees Celsius in the future.
After removing the water layer, we pour the soda solution with constant stirring. It should be about 1 -1.5 liters in terms of 10% soda solution (200 grams of soda per 1,800 ml of water). Strictly speaking it should be poured to about 8, but it is difficult to measure this way (we have to take samples of the aqueous layer out of the reactor). So we pour exactly about 1.2 liters, then start adding 100 ml. Maybe not from the first brew, but you will notice that at some point the faintly lemon-yellow hue of bk-4 solution in xylene in your RM becomes a creamy hue (i.e. more brownish, coffee color). This is usually the point at which you pour just the right amount of baking soda. That's the kind of time-saving tiphook. In general, pouring a little more or a little less baking soda is not a big problem. Once you get the right psch (or the right shade) you stir the solution for 2-3 minutes, and stop the stirrer. You pour the bottom aqueous layer (now that's as much as you poured the soda solution) into the trash. Then you wash your RM three or four times in portions of 1.5 liters of distilled water, following the same scheme - pour water, stir for 2-3 minutes, stop, wait for separation of layers, drain water. The last aqueous layer is drained separately, measure psh - it should not be less than 7. If all is well - washing of bk-4 solution in water is finished, you can proceed to amination.
What I like about this synthesis is amination.
!!! Important-1: The amination reaction must take place at a strictly controlled temperature and time. Sharp temperature fluctuations (especially overheating) or holding the reaction for too long lead to the appearance of side products - isomephe and pyrazines, and strong overheating (about 70 degrees) leads to their appearance within a few minutes. So when you start amination, you need to be sure that your jacket (and thermostat) can provide reliable temperature control. Also (this is important because many people get it wrong here) it's important to be sure that your thermometers accurately show the temperature. It is advisable to have two thermometers (one of which is a liquid analog) in your RM to monitor the temperature just in case the RM, quite aggressively, might damage the main thermometer of your reactor. It is also advisable to calibrate the digital thermometer, also with a liquid of known temperature. And for the supplemental thermometer, it's important to make sure it reaches the level of the RM in your reactor (flask). Reactor loading in this process does not change, and is about 21 liters (we remember that a 20-liter reactor holds about 24 liters of liquid, i.e. something else remains). If you are not sure about the capacity of the reactor, you can add 1-1.5 liters less solvent at the previous stage, this is acceptable. But you must have extra 3 liters of air in the reactor, for stirring, and something else, you will find out below.
!!! Important-2: The temperature-time regime for ortho-xylene and toluene is the same as for benzene. On this basis, I chose 60 degrees and 2.5 hours. In this case, the first 15 minutes are warming up, that is, a little "incomplete". Note that the appearance of iso-meph at 50 degrees and 60 degrees is about the same, which determined my choice. However, some chemists I respect recommend a regime of 50 degrees and 4 hours of time, which may indicate perhaps not quite correct results of the study, but I could not get confirmation of this. In general, the reaction at my chosen parameters is fast and the product is clean, but overheating here is more dangerous than at 50 degrees. Also after the end of the required time RM should be cooled as quickly as possible, separating the layers in parallel and draining the aqueous layer (it will be at the bottom here too), so that side reactions stop as soon as possible, and do not go during the washing after amination. Cooling below 35-40 degrees is quite enough.
The amination reaction on these solvents (benzene/toluene/o-xylene) is characterized by a calm slow but persistent heating, occurring within about 15 minutes. This allows you to set the initial temperature at 35 degrees and turn off the heating/cooling jacket (you can put it on a little cooling, but after 20 minutes you will have to heat it up), turn on the mixer at a decent RPM (in our case - about 1000) immediately pour ALL the methylamine into the PM, and wait for the heating, which peaks at about 15 minutes of reaction. If you have different parameters ( RM volume, jacket reaction rate, thermostat capacity), the starting temperature will be different. In general, I would recommend lowering the start temperature if you increase the PM volume, and increasing it if you decrease it, but you will need to find the exact value yourself.
!!! Important-3: Keeping in mind that overheating above 60 degrees is undesirable, I can give you a good tip. Before starting the reaction, pour 2 liters of cold (ice-cold) distilled water into a dropping funnel or other vessel that can be emptied into the reactor quickly and metered. Adding this water to the RM will have no effect on the reaction, but even half a liter can knock down the temperature of the RM by 3-5 degrees almost instantly, and certainly faster than it rises during heating. This is what a free volume of air in the reactor is for. It should be added when the temperature in the RM exceeds 61 degrees, in small portions, keeping the temperature no higher than 60 degrees.
So, we set the starting temperature, turn on the stirrer at high rpm, turn off the jacket for now (or put it on a little cooling), put the emergency cooler in the funnel above the reactor, pour all the MA at once, and turn on the timer. If one is confident in one's jacket and thermostat, one can set the temperature higher right away and keep it stable with the thermostat, but I focus on flask/homemade reactors, and there the jacket is not that good. And our RM starts to heat up, slowly but inevitably, and within about 15 minutes will reach 60, degrees, with the last degrees being much slower than the previous degrees. When we realize that at 60 degrees the temperature growth is about complete (and all we have heat will be released for about 20 minutes), we turn on the jacket heating to "pick up" and hold the temperature. I have to set the temperature of the heating liquid to 62-63 degrees, turning it off when it exceeds that value, turning it on when it drops to 60 degrees. If everything is done correctly, it will take 15-20 minutes for the temperature in the PM to reach 59-60 degrees, and at this level will be fixed. Next, you are waiting for the most boring 2 hours in this synthesis, but you have to make sure that the temperature does not go around, which, however, is quite easy to do, because the reaction is very predictable. By the end of the reaction, you need to heat more on average, but that's understandable as well. If the temperature starts to jump above 61 degrees, use "emergency cooling", but within reasonable limits.
Further everything is simple. After 2 hours and 30 minutes (where the first 15-20 minutes - heating up and stabilization of temperature) - we sharply change the jacket mode, putting it on maximum cooling (to T = 35 degrees), and in artisanal systems - we pour in cooling water - ice water or pouring ice, we turn off the stirrer, and the layers are divided. The oil turns a light orange color, the water is almost colorless, we drain the water into a separate canister and start extracting and flushing the oil.
By the way, one more note on amination. We took methylamine with 1.5 times mole reserve, and considering that you need 2 moles of it for 1 mole of bk-4, you get 3 times the amount (by moles) of bk-4. If your supplier has a conscience and you didn't store it on the battery with the lid open, this is usually enough, and talk about a 6-fold reserve can be classified as a forum scare story. However, after draining the water layer, it's not a bad idea... just smell it. The smell of urine/ammonia/methylamine tells you that everything is fine, there is enough stock. However, the absence of such an odor, much less the distinct smell of bk-4 tells you that you are out of luck, and your methylamine is not good. And next time you need to add more of it (and maybe change your supplier). I can't say how much more - it depends on the yield of the final product, but thank God I've never come across such exhausted methylamine.
Recall that "oil" we call the free base of mephedrone (free mephedrone base), which is obtained after amination of bk-4. After this reaction it should be washed of methylamine residue (which was taken in excess due to its volatility), as well as methylamine hydrobromide (HB), which is obtained from the "second" mole of MA that binds the hydrogen bromide produced during amination of bk-4. Both of these substances are well water-soluble and insoluble in o-xylene, so they are washed from the "oil" with water. The next stage of acidification is very undesirable, because HB MA and HC MA, which appears during acidification from MA, are first of all water-soluble, just like HC mephedrone, which means that they are very badly washed. And secondly, they are very unhealthy for the health of the user, so do not set up buyers. And you have to wash it cleanly, though at the cost of some losses of the "oil" itself - not without reason, the expected yield of this stage is lower than that of the others.
Why? Because the "oil" itself is water soluble, although worse than in xylene (benzene, toluene). Therefore, it is better to wash with small amounts of water (about 1/10 of your oil layer in xylene, i.e. 1.7 liters per wash) and more often. That way there will be an optimal ratio between the impurities being cleaned out and the care of the "oil" itself. But besides, we have about 5-6 liters of our water layer (and more if you added emergency cooling), there is quite a significant amount of "oil" there, and it should be taken away.
We take it away (scientifically - we extract it) with the same xylene, 4 washes of 500 ml each. We do it BEFORE cleaning the oil with water, to avoid dragging the dirt into the clean oil and to avoid increasing the number of washes. Scientifically it should be done on a separating funnel, carefully separating layers, but we are going to simplify and speed up this process, because in this case we need the top layer, which scientifically leads to a lot of overflowing of smelly liquid. We'll make it simpler, and more approximate:
Take the canister with the drained water layer, and pour 500 ml of xylene directly into it. We close the lid and shake it vigorously for half a minute, then put the lid up, release the pressure that has accumulated there, and wait a couple of minutes for the layers to separate. Then we carefully, through a bottle neck, pour out in a thin stream into another canister or glass beaker (3 liter, no less) the top layer of xylene. If a little of it remains in the canister - no problem, we have three more washes. If we take a little water - no problem. As a whole, we pour about 600-650 ml of liquid by small trickle, taking a bit of water. So we repeat 3 times more, wasting 2 liters of xylene and getting 3 liters of our "cream", which in the receiving glass (canister) will also be divided by 2 liters (give or take) of xylene with contained in it "oil" and half a liter of water, remaining below. This top layer we already pour into the reactor, even more accurately (from the glass at all is more accurate to divide), the remaining water from the canisters and the glass pour into the trash. This is a quick way and for our purposes quite accurate. Xylene and "oil" we pour into the reactor, and we can wash the "oil". The correctness of your actions will be indicated by the fact that the first drain of xylene with "oil" will be quite bright yellow in color, and the last one will be almost colorless.
The "oil", after draining the aqueous layer and adding the extracted "fugitive", takes up about 17 liters in the reactor. And we wash it with water, pure distilled water, WITHOUT any additives. 1.7 liters per wash. We wash it until the flush water, drained into a separate container, no longer smells of urine/ammonia/methylamine. This may take 3 to 6 washes, as many as you need. Up to the third wash, you don't even have to smell it and drain it right away. I wash 5-6 times, the water stops being turbid during this time, which is also a good indicator. The first washings can be divided not very precisely to speed up the process, leaving a bit of emulsion. The last two it is desirable to let stand longer and divide accurately. PSH of the last drained water should be about 8. The whole procedure takes on the reactor with the bottom drain and my water flushing tiphack about 40-45 minutes. Well and your "oil" should lighten somewhat in the process, and be ready to sour.
The oil is ready... Well, ready. It all depends on the method of souring you have chosen, which, as it was shown, should be considered together with the methods of further cleaning. That is, having determined the method of acidification, you determine further the method of cleaning the resulting product.
For this solvent you can recommend two different ways - acidification in anhydrous medium and acidification in aqueous medium with selection of aqueous fraction and its subsequent washing. If you don't mind, I will copy here these schemes from that thread, making a few comments and corrections within the framework of the appeared tiphacks). Yes, the diagrams are still being improved, it's a living process.
!!! Important: you may have noticed that in my prescription, the amount of hydrochloric acid is a calculated thing. That is, if you did everything right, and got the expected results at each step of the synthesis, then I recommend LITTING the acid by calculation, rather than constantly controlling the Psch. Considering that it is acceptable to heat the mixture on acidification up to 40-45 degrees, pouring acid with active stirring and some cooling, i.e. the whole acidification, can take 10-15 minutes. Another thought was not formulated by me, but I am now quoting: "over-acidification by 10% (i.e., adding 10% more acid than necessary) is not terrible, the accuracy of PSH measurement is much lower, and can lead, especially in anhydrous media, to errors of up to 30%." End of quote. So you understand what this means? If there were no critical errors anywhere in the synthesis, then you can pour the acid as calculated (and that calculation is given at the beginning, in determining the amount of reagents). Then you add the acid (or hydrochloric acidic anhydrous solvent) all in, while stirring vigorously, and leave the PM stirring for about 10 more minutes. After that, it is still better to measure the PSH. In case of 5.5 and less (i.e. you got it or a little bit over-acidified), you leave everything as it is, in case of 6 and more you can add 5-10% more acid (it depends on how much you are tired and you want to finish the synthesis), measuring pH after every addition. Thus all acidification takes about 30 minutes, regardless of the method, and we will consider the methods below.
1. There is no need to dry RM before acidification - we add water anyway. We acidify with regular aqueous hydrochloride, but add more distilled water (up to 1 liter per 1 kg of meph). If meth still begins to fall out, add a little more until it dissolves. Under no circumstances should you add either IPA or acetone - they will ruin everything.
2. We try to steep the RM after acidification. It is divided into two layers. Aqueous (it contains meph) and non-aqueous. We pour out the non-aqueous layer or use it for regeneration. We wash the aqueous layer 2-3 times with DXM (better DXM, even if we have a xylene-based scheme, because by experience it removes more dirt). Wash in the same way as we did with water after amination - i.e. we added DXM, stirred, settled, divided layers, poured the layer with DXM (it's at the bottom). The portion volume of DXM is 10% of the volume of the water layer.
3. After that we evaporate amount of aqueous fraction about twice until we have 1 gram of water per 1 kg of meph. Here's a note - changes have been made in relation to the topic about cleaning. If you evaporate further, the meph will fall out, even at 50 degrees and will zasat you all the hoses. Evaporate better under vacuum - even under shallow vacuum water boils at 60-65, and your meph is whole - I remind you that overheating the solution above 85 degrees is not recommended. But there is another tiphak - if you pour a little hydrochloric acid in your water (and if you overacidify it a little, then you do nothing), then in an acidic environment meph can be boiled without vacuum. You can boil mephe (in an acidic environment) in an ordinary pot, and then you can catch up the solution concentration to 400 grams of water per 1.5 kg of mephe, and save the IPS. Just do not burn meph - if you plan to get 3 200 grams of meph, then the total volume of evaporated liquid should not be less than 4 liters (!!!), and preferably 4 100-4 200 ml.
4. Next, we pour a solution or mush, which turns out (if you cooled or evaporated solution) 9 liters of IPS in 2 liters of solution (1.5 kg meph + 400 grams of water), and purify by method 3. If you have 1 liter of water left in the flask for 1 kg of meph, then the IPS should be poured in twice as much, and evaporate more, too. But all in a closed system.
5. We put it in freezer, wait for night, get precipitate (practically pure crystallius). Then we rinse it with acetone. Depending on purity, we use 1 or 2 times. Profit.
This method requires neither extra reagents, nor drying, nor long filtration. For 5 kg of meph, you can fit in 8 hours all the stages except the last rinse with acetone. In addition, due to the combination of three cleaning methods and three different solvents (DXM, IPS, acetone) all impurities are washed out much better.
An additional plus is that the solvents (xylene/ benzene/toluene, IPS, acetone) are NOT MIXED and thus can be easily regenerated. Regeneration of solvents I think is a VERY important topic, not at the expense of savings, but at the expense of reduced procurement, and thus the smelliness of the lab, reducing waste - also reduces smelliness. Well, and carry on their own in the fields and woods is also less. Solvents can be regenerated in all methods, with varying success, but in most cases successfully, read the article on the subject - it is also mentioned among the articles at the beginning of this thread.
That's about it. Use it. The process is alive. Thank you.
p.s. I am also actively looking for sponsors for this project.
Let's figure out what and how in moles will be to our favorite reagents and reactions. So, what we know about them, and what we get (check the calculations yourself).
1. 4-methylpropiophenone (4-mpf), formula C10H12O, molar mass 148,2, 99% liquid, density 0,963 (according to other sources density 0,993).
Thus, 1 mole of 4-MPH is 148.2 grams, taking into account the concentration of 148.2/99% = 149.7 grams, or taking into account the density = 155.5 ml.
2. Bromohydrogen (HBr), formula HBr, molar mass 80.91, gas, 48% pure aqueous solution, density 1.5
Thus, 1 mole of HBr=80.91 grams, or taking into account the concentration of 168.5 grams of 48% aqueous solution, or taking into account the density of 112.5 ml
3. Hydrogen peroxide, formula H2O2, molar mass 34.01, gas, 37-60% aqueous solution, density 1.14-1.2
4. Methylamine (MA), formula CH3NH2, molar mass 31.1, gas, 38% solution in water, density 0.9
Thus, 1 mole of MA in 38% solution would be 82 grams of 38% solution, or 91 ml taking into account the density.
5. Chlorohydrogen (which is sometimes hydrochloric acid), formula HCl, molar mass 36.46, gas, 36% aqueous solution, density 1.18
Thus 1 mole of HCl in 36% solution would be 101.3 grams of 36% solution, or taking into account the density of 86 ml.
If HCl is dissolved in IPS (hydrochloric acid IPS, 30% solution) or dioxane (hydrochloric acid dioxane 26% solution), we have:
- 1 mole HCl in IPS = 121.5 grams
- 1 mole of HCl in dioxane = 140.2 grams.
6. Bromo-4-Methylpropiophenone (Bromketon-4, BK-4), formula C10H11OBr, molecular mass 227.1
7. Free mephedrone base (mepha CO, "oil"), formula C11H15NO, molecular mass 177,24
8. Mephedrone hydrochloride (HC mepha), formula C11H15NO*HCl, molecular mass 213.7
I apologize to the chemists for such a sloppy spelling.
You can calculate the formula and molar mass of iodine ketone by yourself, taking into account that instead of bromine (Br, molar weight 79.91) there is iodine (I, molar weight 126.9). This also explains why it takes more iodo ketone than bromo ketone to make the same amount of mephedrone: it is heavier per molecule.
This prescription uses minimal but professional equipment. Flasks, tubes, transitions. I have a bad attitude towards "pot" syntheses, because it is fundamentally impossible to achieve normal yields and quality in them.
I'm not against the free distribution of this script, but I'd like to be referred to and liked. However, there are no obligatory actions here either, everything is up to you.
Steps (basic and intermediate) in the synthesis of mephedrone:
1.1 Bromination of 4-mpf with Hbr and H2O2 ("Green Bromination")
Reaction formulas (here two reactions go in parallel, a part of the result of the second reaction is returned as a starting reagent for the first one):
- 2HBr+H2O2=Br2+2H2O and
- C10H12O+Br2= C10H11OBr+HBr
TOTAL REACTION: C10H12O+HBr+H2O2= C10H11OBr+2H2O
Reaction result - Bromketon-4, BK-4, C10H11OBr
1.2 Washing after bromination.
Necessary to remove residual bromine and acid from the resulting bk-4.
1.3 Amination of BK-4 with methylamine to yield mephedrone
Reaction formula:
- C10H11Br+2СH5N=C11H15NO+HBr*CH5N
Reaction result - Free base of mephedrone (oil, freebase), C11H15NO
1.4 Washing after amination.
Necessary to remove residual methylamine (MMA) and from the resulting mephedrone
1.5 Acidification with hydrochloric acid (aqueous hydrogen chloride solution) with release of aqueous solution of 4-MMS
Reaction formula - C11H15NO+HCl=C11H15NO*HCl
Reaction result - mephedrone hydrochloride, C11H15NO*HCl
1.6 Washing after acidification.
Necessary in order to clean the aqueous solution of HC 4-MMS (mef) from the organic-soluble dirt.
This step only makes sense if you have chosen among the acidification methods Acidification to the aqueous fraction, and it can in principle be considered as the beginning of cleaning. But since it is carried out on the reactor as part of the same loading and the same procedures, I mention it as one part of the synthesis.
For step 1.1. (BROMING)
Reagent calculations for 30 moles:
4-mpf (the main precursor for making mephedrone):
----- 30 moles of 4-mpf is 4,491 grams or 4,536 ml. We take into account here the concentration (99%) and density (99%) of 4-mpf
TOTAL is 4,491 grams or 4,536 ml.
HBr (Hydrogen Bromide Acid - aqueous solution):
----- 30 moles of Hbr (that's 2,428 g pure or 5,060 g 48% solution, or 3,395 ml) PLUS 5% stock
TOTAL of Hbr is 5,310 grams, or 3,570 ml
Hydrogen peroxide (we recommend taking a concentration no higher than 37%, higher concentrations are a fire hazard):
----- 30 moles of H2O2 (that's 1,020 g pure or 2,756 g 37% solution or 2,418 ml) PLUS a 10% reserve
TOTAL 37% PERKISSION - 3,033 grams or 2,660 ml
If you bought a different concentration of peroxide, you can easily (using the information in the article "Molar Calculus for Dummies") recalculate to the amount you need.
The maximum possible theoretical yield from this step is 20 moles, or 4,542 grams of BK-4.
Estimated yield including losses on synthesis and washes - 93% - 28 moles or 6 360g of BK-4
For step 1.2
For decolorization and removal of acidity you need (minimum)
- Sodium sulfite 20% solution - 400 ml, i.e. approximately 80 grams of sodium sulfite dissolved in 320 ml of water.
- Sodium baking soda 6% puree - 1,400 ml, i.e. approximately 230 grams of soda dissolved in 1,170 ml of water.
BUT: this is if you have properly drained the aqueous layer without leaving any significant residual water (with bromine and acid). Therefore, we advise you to make twice or maybe THREE times as much of these reagents, and add in small portions - sodium sulfite - until the PM discolors, and soda - until the Psch is at least 6-7. In this case reagents may go more - it happens.
After these operations we add the solvent - in this case ortho-xylene in the amount of
----- 250 ml/mol*30 moles = 7,500 ml or, taking into account its density of 0.88 = 6,600 g.
For step 1.3. (AMINING)
Calculation of reagents for 28 moles:
BK-4 (output from BROMING):
----- 6,360 g. BK-4
TOTAL: 6 360 grams
Solvent (poured in at the previous step - washing).
----- o-xylene, the solvent in which BK-4 was dissolved after washing in the previous stage.
TOTAL: 6,600 grams or 7,500 ml
Methylamine (MonoMethylamine, MMA).
----- NOTE. The stage requires TWO moles of MMA per 1 mole of BK-4, plus a reserve of 1.4. So you get 2*1.4*28=78.4 moles of MMA, or 2437 grams pure. Make sure your aqueous solution of MMA is not exhausted and matches the concentration, or take a larger stock(!)
TOTAL: 6,400 grams of 38% aqueous solution, or 7,030 ml.
Maximum theoretical yield is 28 moles or 4,960 grams of mephedrone.
Planned yield including losses on synthesis and washes - 78.5% - 22 moles or 3,900 grams of mephedrone.
For step 1.4
Distilled water is used to flush the oil in the solvent. One portion of flushing is about 1/10 of RM volume, i.e. 1 400-1500 ml
TOTAL: Distilled water in the amount of 1400 ml*Number of washes. There can be from 3 to 6 flushes. We recommend stocking up on 10 liters of water just in case.
In addition, 2 portions of solvent (o-xylene) about 500 ml each will be needed for oil extraction from the drained water layer.
TOTAL: 1000 ml of o-xylene to extract the oil from the aqueous layer.
For step 1.5
Calculation of reagents for 22 moles:
Mephedrone (Freebase 4-MMC, "oil"):
----- 3,900 grams (yield from the AMINING step)
TOTAL: 3,900 grams
SOLUTION (Ortoxylol, O-xylol):
7,500 ml poured into the 1.2. - washing after the BROMING step. PLUS 1000 ml used to extract the "oil" in step 3.4. - washing after the AMINING step)
TOTAL: 8,500 ml
Further the set of reagents differs depending on the acidification method you choose.
For anhydrous acidification (for vessels that do not have a bottom drain):
Hydrochloric acid IPS (hydrogen chloride gas solution in isopropyl alcohol):
----- 22 moles of HCl is 801 g of pure hydrogen chloride, or 2,670 g. 30% solution in IPS, or 2,500 ml of solution.
TOTAL is 1,670 grams of 30% HCl solution in IPS, or 2,500 ml.
For acidification into the aqueous fraction (for reactors):
Hydrochloric acid (hydrogen chloride gas solution in water):
----- 22 moles of HCl is 801 g of pure hydrogen chloride, or 2,225 g. 36% aqueous solution, or 1,885 ml of solution.
TOTAL is 2,225 grams of 36% aqueous solution, or 1,885 ml.
Distilled water: to ensure solubility of ALL GC MMA in water, it is recommended to pour approximately 2.5 times more water than the hydrochloric acid used.
TOTAL 4 700 ml distilled water
The maximum theoretical yield is 4,700 g. GC of mephedrone.
Planned yield including washes -- 95% -- is 21 mol or 4,488 grams.
For step 1.6 (if Acidification into aqueous fraction is selected).
DXM is used to wash the aqueous fraction in solvent. Washing is done after draining of the organic layer. One portion of washing is approximately 1/10 of the volume of the remaining aqueous fraction, PM, i.e. 1,100 ml. Usually 2-3 washes are enough.
TOTAL: DXM in an amount of 1 100 ml*Number of washes.
Stage 1. Bromination of 4-mpf with Hbr and H2O2
1.1 Preparation.
The reactor (reaction vessel) is filled with 4-mpf and Hbr in the indicated amounts (completely). Hydrogen peroxide is poured into a dropping funnel (or any other feeding device, such as a metering pump). All reagents are at room temperature. The cooling/heating system of the reactor is set to cool the RM for the first 15-20 minutes, so that as much peroxide as possible can be poured during this time. However, after 10 minutes of reaction, the temperature in the RM should exceed 70-75 degrees. If you can't do that, you will have to heat the RM much more than 1/3 of the peroxide, and the whole reaction will go half as slow. The yield may also be less. All the reaction should preferably be carried out in the temperature range of 70-85 degrees Celsius, and be prepared after 15-20 minutes of reaction on the contrary, start heating RM, so that the temperature in the RM has not fallen below 70 (preferably 75) degrees. Since the heat until about 1/2 of the peroxide will be released actively, the temperature of the heating fluid is put at about 60 degrees, then raised to 70-75 degrees.
!!! Important-1: In contrast to many prescriptions, the high reaction temperature is useful and greatly accelerates the passage of this stage and does not affect the purity of the product. But the presence of UV rays is harmful for the reaction - by-products are formed. Therefore, it is advisable to completely remove natural light, turn off all light sources (including fluorescent and LED), and the reaction should be carried out in yellow light (halogen, incandescent, LED lamps with a color temperature of 2500-3000K). Ideally, purchase and turn on special UV-free lamps (yellow light). Since this light is unlikely to be sufficient, have a portable lamp (preferably yellow too) to illuminate the part of the reactor you want to see what state your RM is in.
!!! Important-2: There is no time limit on the reaction. No byproducts will form if you make it longer. So, for example, if you get into the temperature range of 75-85 degrees, the entire reaction will complete in about 1:00 - 1:15 time, but if the temperature stays below 70 degrees, you may need 3:00 - 3:30 time, or more (up to 4:30)
!!!Important-3: Two reactions run in parallel in the bromination process, and each is accompanied by a release of heat.
- 2HBr+H2O2=Br2+2H2O and
- C10H12O+Br2= C10H11OBr+HBr
It is assumed that almost all of the heat is released in the first reaction, but this is not true-they are both approximately equally exothermic. Each of the reactions has its own distinctive feature - the first reaction releases molecular bromine, which colors the PM yellow-orange-red-dark maroon. The second reaction, on the contrary, bleaches PM (fully or partially) and releases gaseous HBr - i.e. the same BVK, which is mostly absorbed by PM, but may escape (not have time to be absorbed) through your absorption cascades as caustic acid gas.
At the beginning of the synthesis, they proceed at about the same rate, or even a second faster. However, after about half of the 4mpf has been reacted, the second reaction slows down and the RM becomes permanently stained, in greater or lesser shades of red. The second reaction is also autocatalytic, or, simply put, maintains itself, that is, it occurs in "bursts," resulting in a strong release of HBr, and the RM becomes strongly discolored. This course of the reaction is normal and should not be feared, but the droppers inserted into the reactor and the RETURN COOLER should be secured so that they are not knocked out by an increase in pressure. In addition, the start of the next "burst" of the second reaction can be provoked, for example, by stopping stirring for 2-3 minutes, or a sharp change in stirrer speed, not to accumulate products of the first reaction and let the second go more often with less reagents, which will make your reaction calmer. Also, in the second half of the synthesis, HBr, which is formed in the second reaction, may be needed to keep it going. Therefore, if the PM is very red, you should stop pinning down the peroxide (which in the absence of free HBr in the second half of the synthesis may just decompose and not go to the right thing) and turn off the stirring for 2-3 minutes to let the second part of the reaction "start".
Conducting.
So, you turn on the stirrer to speeds that ensure good mixing (we have 450-550 rpm), and start adding peroxide at the highest possible speed. Your RM heats up almost instantly (here - up to 75 degrees in 8-10 minutes). Once it reaches 75 degrees, the RM bleaches almost instantly for the next 20-25 minutes. Next, you set the peroxide dip so that the RM does not heat up above 80 degrees (that is, you reduce it by half or three times), and keep this temp for the next 20 minutes while the RM bleaches or almost bleaches (to a yellow color). After adding about 35-40% peroxide, (this takes about 20-25 minutes from the start of the reaction) you need to turn off the cooling, and turn on the heating, so that the coolant temp is not below 55, and preferably 60 degrees. This is to ensure that the resulting bk-4, due to the difference in temperature inside the RM and on the walls of the reactor did not fall out on the walls as a solid (Tp Bk-4 - 52 degrees). This is extremely undesirable - precipitating uk "traps" unreacted 4-mpf in itself, and can greatly reduce the yield of uk-4. So make sure that all of your RM is liquid, because the temperature inside the RM (where the thermometer is) and at the reactor walls can be very different. In case of precipitation of bk-4 in solid form we urgently heat jacket (heating liquid) of reactor to 65-70 degrees to melt bk-4. If necessary, we stop the peroxide pouring out. In general - it is much better to prevent such a development, as well as failure to reach the temperature of RM above 70 degrees, as it greatly increases the reaction time. Temporary heating to 90 degrees is not terrible, you just stop dipping and wait for RM to cool down. Critical is a temperature of 100 degrees, because the RM can boil, which should not be allowed either.
In the second half of the synthesis, for the reasons described above, the PM stops discoloring, acquiring a red hue. Here we carefully watch the color of RM, if a dark red/burgundy hue appears, as well as reddish vapors coming out of the reactor, we understand that we have a large excess of bromine, and therefore probably a lack of HBr (which will appear again after the passage of the second reaction). And this means - we need to stop the peroxide addition (it can decompose in vain) and try to "provoke" the beginning of the second reaction by stopping the stirrer for 2-3 minutes (to zero) and then abruptly changing its rotation speed by any number of revolutions, from 0 to maximum. These measures should be enough to make your PM start to decolorize, and the HBr not retained in the RM went through the cascades (we remember that there is a reserve). However, the RM will not decolorize to white as in the beginning of the synthesis, and once you achieve a light orange color, the peroxide addition must be resumed. This will happen several times (depending on the depth of discoloration), and the dark red color will build up faster, and the discoloration will happen less often, and with more "provocations". Before the last 10-15% of the peroxide is added, you should try to maximize bleaching. The temperature at this point will no longer rise by more than 3-4 degrees, and the temperature of the heating fluid in the jacket should not be below 70 degrees, to avoid crystallization of bk-4. In general, if you keep the temperature within 75-85 degrees, this stage is reached in about 40-50 minutes, at temperatures below that, it may take up to 3 hours. But if you're caught in a decrease in RM temperature below 70 degrees, or even more so, the crystallization of bk-4, you need to focus as much effort as possible on warming up the RM. At this stage, you are likely to have HBr bubbling in the cascades anyway, and if the "t" is over 75 and bubbling, the peroxide addition should be suspended for a while (until the bubbling is over).
Then you pour in the remaining 10-15% peroxide at a fast pace, and stir the PM for another 10-15 minutes. It won't discolor much anymore, and the excess HBr will be bubbling in your cascades. If the reaction was carried out quite well, the excess peroxide will bubble in the cascades - its bubbling differs from HBr in that it does not coincide in time with decolorization (HBr release coincides), and is equal in the first and second vials of the cascade (HBr, due to its absorption by soda or alkali, has less bubbling in the second vial). In any case, you pour out all the peroxide, and the stock of HBr and peroxide should be enough for you to get all the 4-mpf pro-rominated. After that, you try to brominate the rest of 4-mpf in your PM by the above described "provocations", several times, spending 15 minutes, as an alternative - leave the RM with the mixer off for half an hour, not forgetting to heat, then sharply turn the mixer to the maximum rpm. Bromination of residual 4-mpf will be visually seen as "flowers" or "salutes" rising from the depths of the RM, accompanied by bubbles - very well seen on the surface of the RM when the stirrer is stopped - they appear in 1-2 minutes after stopping. When after several provocations, such traces stop appearing, your 4-mpf has reacted.
Take your time the first few times, remember that procrastinating reaction time, especially if you haven't reached the right temperature, will not ruin your product. And it's better to spend both 3 and 4 hours to get the maximum yield. You can tweak the optimal time and temperature later. So if there are any problems (not discolored in time, for example) just increase the time, remembering to heat the PM to the right temperature. To look at the condition and color of the RM you need a portable lamp on a long cord (I usually look at the top of the RM and the "tail" (bottom drain) of the reactor). The bottom drain, due to the fact that it is outside the jacket, usually by 2/3 of the synthesis time is clogged with solid precipitated bk - there is nothing you can do about it, it will then be dissolved at the next stage. Often also solid BK falls out on the lid and on top of the reactor walls (from inside, of course) - the jacket does not reach there as well - this too will go to dissolution later.
So, bromination of 4-mpf is finished, provocations do not give visible bubbles, so bromination is finished. The temperature of RM is kept only by the jacket and it goes down to 68-70 degrees. We reduce the temperature of the jacket (heating tank) to 60 degrees and immediately proceed to the neutralization and rinsing of the RM.
Washing of RM after bromination.
As I said before, it is possible (and desirable) to wash immediately after bromination, not allowing RM to cool below the crystallization temperature of bk-4, in order not to warm it up painfully and for a long time afterwards. I'm serious - first of all, the temperature difference between the center and the edges of the reactor can be quite large, which will complicate the melting of bk-4, and secondly - the solvent can be poured only after the RM decolorization by sodium thiosulfate.
Important. The solvent (in our case ortho-xylene) must be poured only after decolorization of RM, because it itself is well brominated by bromine, which remained in our RM, thereby giving a by-product. So we bleach the PM first. For this purpose you have to have in a small dropping funnel (250-500 ml) diluted 10% solution of sodium thiosulfate (30 grams of thiosulfate per 270 grams of water or 50 grams per 450 ml of water). If the funnel is 250 ml, you can make a stronger solution, or refill it as you go. Depending on different parameters (quality of your HBr, presence of bromine, speed of reaction, etc. - you may need from 200 to 400 ml of solution). The thiosulfate solution spoils in the air, not quickly but surely, so it is more correct to make it right before the reaction.
So, you put a small dropping funnel with the solution and turn on a good stirring (we have about 450 rpm) and start pouring the solution. You can pour the first 100-150 ml as quickly as possible, then add 20-50 ml as needed, depending on the color of the RM. Keep in mind that bleaching is not instantaneous, it takes several minutes. Your RM begins to bleach, through yellow to white. If you did the reaction correctly, a milky white RM color is achieved. Actually, when this color is reached, the infusion of the thiosulfate solution can be stopped, the white color is the only criterion for the sufficiency of the infusion. If you performed the reaction with a side effect (in the light, for example), the RM will remain yellowish in color. Then the infusion should be stopped if the color does not change after another 20-30 ml infusion. If you have residuals of bk-4 frozen somewhere in RM with a color other than white (e.g., orange), you can have an "extra" 50 ml after stopping the decolorization so that after adding solvent and dissolving these pieces, the thiosulfate will "intercept" this bromine as well. In general, a small excess of thiosulfate will not harm your RM.
The temperature of your RM by pouring thiosulfate solution at room temperature and stirring will drop to about 60-65 degrees, you can't go lower than that, you have to warm it up with a jacket. And it's time to pour the solvent, preferably also measured in advance. In general, it is better to measure and pour all reagents for the synthesis into flasks/canisters (preferably with a spout) at once so as not to waste time on this work during the synthesis.
Then we pour in the necessary amount of ortho-xylene and stir. Our RM becomes white and turbid when stirred, as the temperature drops. However, dissolution is going on, and if during this dissolution your RM turns yellow again (i.e. somewhere unaccounted bromine came out), you can add more thiosulfate solution. According to my experience, longest dissolves "tail" of reactor (bottom drain), which we have outside the heating zone, but it dissolves in 15-20 minutes, it needs to provide good stirring and temperature of RM at least 50-55 degrees (heating, if necessary by jacket) - and this "tail" will melt by "funnel" of water and solvent, by flow, which will provide stirrer. As a last resort, such "dead" zones can be heated with a construction dryer, but not exposing it to temperatures over 150 degrees, so that the glass does not crack. bk-4, stuck on the top of the reactor walls and on the lid (from inside) is washed off by a sharp change in speed of the mixer, which creates waves and splashes of solvent. Our reactor is filled high enough, so these waves and splashes will wash away the solidified bk-4.
When dissolution is complete and there is no solid bk-4 left in the bottom drain and other corners of the reactor, the agitator is turned off and the layers are split. The top layer you should have is bk-4 dissolved in xylene, it should be about 15,5-16 liters. The bottom layer is water with the impurities removed - about 4 liters or a little more (if you used 37% peroxide. The bottom layer is drained into the waste, and only then is the acid neutralized (since most of the acid goes into the aqueous layer, and we save a lot of soda and traffic). The heating of the reactor jacket can be turned off, as we will need a RM temperature of about 35 degrees Celsius in the future.
After removing the water layer, we pour the soda solution with constant stirring. It should be about 1 -1.5 liters in terms of 10% soda solution (200 grams of soda per 1,800 ml of water). Strictly speaking it should be poured to about 8, but it is difficult to measure this way (we have to take samples of the aqueous layer out of the reactor). So we pour exactly about 1.2 liters, then start adding 100 ml. Maybe not from the first brew, but you will notice that at some point the faintly lemon-yellow hue of bk-4 solution in xylene in your RM becomes a creamy hue (i.e. more brownish, coffee color). This is usually the point at which you pour just the right amount of baking soda. That's the kind of time-saving tiphook. In general, pouring a little more or a little less baking soda is not a big problem. Once you get the right psch (or the right shade) you stir the solution for 2-3 minutes, and stop the stirrer. You pour the bottom aqueous layer (now that's as much as you poured the soda solution) into the trash. Then you wash your RM three or four times in portions of 1.5 liters of distilled water, following the same scheme - pour water, stir for 2-3 minutes, stop, wait for separation of layers, drain water. The last aqueous layer is drained separately, measure psh - it should not be less than 7. If all is well - washing of bk-4 solution in water is finished, you can proceed to amination.
Amination.
What I like about this synthesis is amination.
!!! Important-1: The amination reaction must take place at a strictly controlled temperature and time. Sharp temperature fluctuations (especially overheating) or holding the reaction for too long lead to the appearance of side products - isomephe and pyrazines, and strong overheating (about 70 degrees) leads to their appearance within a few minutes. So when you start amination, you need to be sure that your jacket (and thermostat) can provide reliable temperature control. Also (this is important because many people get it wrong here) it's important to be sure that your thermometers accurately show the temperature. It is advisable to have two thermometers (one of which is a liquid analog) in your RM to monitor the temperature just in case the RM, quite aggressively, might damage the main thermometer of your reactor. It is also advisable to calibrate the digital thermometer, also with a liquid of known temperature. And for the supplemental thermometer, it's important to make sure it reaches the level of the RM in your reactor (flask). Reactor loading in this process does not change, and is about 21 liters (we remember that a 20-liter reactor holds about 24 liters of liquid, i.e. something else remains). If you are not sure about the capacity of the reactor, you can add 1-1.5 liters less solvent at the previous stage, this is acceptable. But you must have extra 3 liters of air in the reactor, for stirring, and something else, you will find out below.
!!! Important-2: The temperature-time regime for ortho-xylene and toluene is the same as for benzene. On this basis, I chose 60 degrees and 2.5 hours. In this case, the first 15 minutes are warming up, that is, a little "incomplete". Note that the appearance of iso-meph at 50 degrees and 60 degrees is about the same, which determined my choice. However, some chemists I respect recommend a regime of 50 degrees and 4 hours of time, which may indicate perhaps not quite correct results of the study, but I could not get confirmation of this. In general, the reaction at my chosen parameters is fast and the product is clean, but overheating here is more dangerous than at 50 degrees. Also after the end of the required time RM should be cooled as quickly as possible, separating the layers in parallel and draining the aqueous layer (it will be at the bottom here too), so that side reactions stop as soon as possible, and do not go during the washing after amination. Cooling below 35-40 degrees is quite enough.
The amination reaction on these solvents (benzene/toluene/o-xylene) is characterized by a calm slow but persistent heating, occurring within about 15 minutes. This allows you to set the initial temperature at 35 degrees and turn off the heating/cooling jacket (you can put it on a little cooling, but after 20 minutes you will have to heat it up), turn on the mixer at a decent RPM (in our case - about 1000) immediately pour ALL the methylamine into the PM, and wait for the heating, which peaks at about 15 minutes of reaction. If you have different parameters ( RM volume, jacket reaction rate, thermostat capacity), the starting temperature will be different. In general, I would recommend lowering the start temperature if you increase the PM volume, and increasing it if you decrease it, but you will need to find the exact value yourself.
!!! Important-3: Keeping in mind that overheating above 60 degrees is undesirable, I can give you a good tip. Before starting the reaction, pour 2 liters of cold (ice-cold) distilled water into a dropping funnel or other vessel that can be emptied into the reactor quickly and metered. Adding this water to the RM will have no effect on the reaction, but even half a liter can knock down the temperature of the RM by 3-5 degrees almost instantly, and certainly faster than it rises during heating. This is what a free volume of air in the reactor is for. It should be added when the temperature in the RM exceeds 61 degrees, in small portions, keeping the temperature no higher than 60 degrees.
So, we set the starting temperature, turn on the stirrer at high rpm, turn off the jacket for now (or put it on a little cooling), put the emergency cooler in the funnel above the reactor, pour all the MA at once, and turn on the timer. If one is confident in one's jacket and thermostat, one can set the temperature higher right away and keep it stable with the thermostat, but I focus on flask/homemade reactors, and there the jacket is not that good. And our RM starts to heat up, slowly but inevitably, and within about 15 minutes will reach 60, degrees, with the last degrees being much slower than the previous degrees. When we realize that at 60 degrees the temperature growth is about complete (and all we have heat will be released for about 20 minutes), we turn on the jacket heating to "pick up" and hold the temperature. I have to set the temperature of the heating liquid to 62-63 degrees, turning it off when it exceeds that value, turning it on when it drops to 60 degrees. If everything is done correctly, it will take 15-20 minutes for the temperature in the PM to reach 59-60 degrees, and at this level will be fixed. Next, you are waiting for the most boring 2 hours in this synthesis, but you have to make sure that the temperature does not go around, which, however, is quite easy to do, because the reaction is very predictable. By the end of the reaction, you need to heat more on average, but that's understandable as well. If the temperature starts to jump above 61 degrees, use "emergency cooling", but within reasonable limits.
Further everything is simple. After 2 hours and 30 minutes (where the first 15-20 minutes - heating up and stabilization of temperature) - we sharply change the jacket mode, putting it on maximum cooling (to T = 35 degrees), and in artisanal systems - we pour in cooling water - ice water or pouring ice, we turn off the stirrer, and the layers are divided. The oil turns a light orange color, the water is almost colorless, we drain the water into a separate canister and start extracting and flushing the oil.
By the way, one more note on amination. We took methylamine with 1.5 times mole reserve, and considering that you need 2 moles of it for 1 mole of bk-4, you get 3 times the amount (by moles) of bk-4. If your supplier has a conscience and you didn't store it on the battery with the lid open, this is usually enough, and talk about a 6-fold reserve can be classified as a forum scare story. However, after draining the water layer, it's not a bad idea... just smell it. The smell of urine/ammonia/methylamine tells you that everything is fine, there is enough stock. However, the absence of such an odor, much less the distinct smell of bk-4 tells you that you are out of luck, and your methylamine is not good. And next time you need to add more of it (and maybe change your supplier). I can't say how much more - it depends on the yield of the final product, but thank God I've never come across such exhausted methylamine.
Extraction of the "oil" from the aqueous layer and washing the "oil" after amination.
Recall that "oil" we call the free base of mephedrone (free mephedrone base), which is obtained after amination of bk-4. After this reaction it should be washed of methylamine residue (which was taken in excess due to its volatility), as well as methylamine hydrobromide (HB), which is obtained from the "second" mole of MA that binds the hydrogen bromide produced during amination of bk-4. Both of these substances are well water-soluble and insoluble in o-xylene, so they are washed from the "oil" with water. The next stage of acidification is very undesirable, because HB MA and HC MA, which appears during acidification from MA, are first of all water-soluble, just like HC mephedrone, which means that they are very badly washed. And secondly, they are very unhealthy for the health of the user, so do not set up buyers. And you have to wash it cleanly, though at the cost of some losses of the "oil" itself - not without reason, the expected yield of this stage is lower than that of the others.
Why? Because the "oil" itself is water soluble, although worse than in xylene (benzene, toluene). Therefore, it is better to wash with small amounts of water (about 1/10 of your oil layer in xylene, i.e. 1.7 liters per wash) and more often. That way there will be an optimal ratio between the impurities being cleaned out and the care of the "oil" itself. But besides, we have about 5-6 liters of our water layer (and more if you added emergency cooling), there is quite a significant amount of "oil" there, and it should be taken away.
We take it away (scientifically - we extract it) with the same xylene, 4 washes of 500 ml each. We do it BEFORE cleaning the oil with water, to avoid dragging the dirt into the clean oil and to avoid increasing the number of washes. Scientifically it should be done on a separating funnel, carefully separating layers, but we are going to simplify and speed up this process, because in this case we need the top layer, which scientifically leads to a lot of overflowing of smelly liquid. We'll make it simpler, and more approximate:
Take the canister with the drained water layer, and pour 500 ml of xylene directly into it. We close the lid and shake it vigorously for half a minute, then put the lid up, release the pressure that has accumulated there, and wait a couple of minutes for the layers to separate. Then we carefully, through a bottle neck, pour out in a thin stream into another canister or glass beaker (3 liter, no less) the top layer of xylene. If a little of it remains in the canister - no problem, we have three more washes. If we take a little water - no problem. As a whole, we pour about 600-650 ml of liquid by small trickle, taking a bit of water. So we repeat 3 times more, wasting 2 liters of xylene and getting 3 liters of our "cream", which in the receiving glass (canister) will also be divided by 2 liters (give or take) of xylene with contained in it "oil" and half a liter of water, remaining below. This top layer we already pour into the reactor, even more accurately (from the glass at all is more accurate to divide), the remaining water from the canisters and the glass pour into the trash. This is a quick way and for our purposes quite accurate. Xylene and "oil" we pour into the reactor, and we can wash the "oil". The correctness of your actions will be indicated by the fact that the first drain of xylene with "oil" will be quite bright yellow in color, and the last one will be almost colorless.
The "oil", after draining the aqueous layer and adding the extracted "fugitive", takes up about 17 liters in the reactor. And we wash it with water, pure distilled water, WITHOUT any additives. 1.7 liters per wash. We wash it until the flush water, drained into a separate container, no longer smells of urine/ammonia/methylamine. This may take 3 to 6 washes, as many as you need. Up to the third wash, you don't even have to smell it and drain it right away. I wash 5-6 times, the water stops being turbid during this time, which is also a good indicator. The first washings can be divided not very precisely to speed up the process, leaving a bit of emulsion. The last two it is desirable to let stand longer and divide accurately. PSH of the last drained water should be about 8. The whole procedure takes on the reactor with the bottom drain and my water flushing tiphack about 40-45 minutes. Well and your "oil" should lighten somewhat in the process, and be ready to sour.
Souring .
The oil is ready... Well, ready. It all depends on the method of souring you have chosen, which, as it was shown, should be considered together with the methods of further cleaning. That is, having determined the method of acidification, you determine further the method of cleaning the resulting product.
For this solvent you can recommend two different ways - acidification in anhydrous medium and acidification in aqueous medium with selection of aqueous fraction and its subsequent washing. If you don't mind, I will copy here these schemes from that thread, making a few comments and corrections within the framework of the appeared tiphacks). Yes, the diagrams are still being improved, it's a living process.
!!! Important: you may have noticed that in my prescription, the amount of hydrochloric acid is a calculated thing. That is, if you did everything right, and got the expected results at each step of the synthesis, then I recommend LITTING the acid by calculation, rather than constantly controlling the Psch. Considering that it is acceptable to heat the mixture on acidification up to 40-45 degrees, pouring acid with active stirring and some cooling, i.e. the whole acidification, can take 10-15 minutes. Another thought was not formulated by me, but I am now quoting: "over-acidification by 10% (i.e., adding 10% more acid than necessary) is not terrible, the accuracy of PSH measurement is much lower, and can lead, especially in anhydrous media, to errors of up to 30%." End of quote. So you understand what this means? If there were no critical errors anywhere in the synthesis, then you can pour the acid as calculated (and that calculation is given at the beginning, in determining the amount of reagents). Then you add the acid (or hydrochloric acidic anhydrous solvent) all in, while stirring vigorously, and leave the PM stirring for about 10 more minutes. After that, it is still better to measure the PSH. In case of 5.5 and less (i.e. you got it or a little bit over-acidified), you leave everything as it is, in case of 6 and more you can add 5-10% more acid (it depends on how much you are tired and you want to finish the synthesis), measuring pH after every addition. Thus all acidification takes about 30 minutes, regardless of the method, and we will consider the methods below.
1. There is no need to dry RM before acidification - we add water anyway. We acidify with regular aqueous hydrochloride, but add more distilled water (up to 1 liter per 1 kg of meph). If meth still begins to fall out, add a little more until it dissolves. Under no circumstances should you add either IPA or acetone - they will ruin everything.
2. We try to steep the RM after acidification. It is divided into two layers. Aqueous (it contains meph) and non-aqueous. We pour out the non-aqueous layer or use it for regeneration. We wash the aqueous layer 2-3 times with DXM (better DXM, even if we have a xylene-based scheme, because by experience it removes more dirt). Wash in the same way as we did with water after amination - i.e. we added DXM, stirred, settled, divided layers, poured the layer with DXM (it's at the bottom). The portion volume of DXM is 10% of the volume of the water layer.
3. After that we evaporate amount of aqueous fraction about twice until we have 1 gram of water per 1 kg of meph. Here's a note - changes have been made in relation to the topic about cleaning. If you evaporate further, the meph will fall out, even at 50 degrees and will zasat you all the hoses. Evaporate better under vacuum - even under shallow vacuum water boils at 60-65, and your meph is whole - I remind you that overheating the solution above 85 degrees is not recommended. But there is another tiphak - if you pour a little hydrochloric acid in your water (and if you overacidify it a little, then you do nothing), then in an acidic environment meph can be boiled without vacuum. You can boil mephe (in an acidic environment) in an ordinary pot, and then you can catch up the solution concentration to 400 grams of water per 1.5 kg of mephe, and save the IPS. Just do not burn meph - if you plan to get 3 200 grams of meph, then the total volume of evaporated liquid should not be less than 4 liters (!!!), and preferably 4 100-4 200 ml.
4. Next, we pour a solution or mush, which turns out (if you cooled or evaporated solution) 9 liters of IPS in 2 liters of solution (1.5 kg meph + 400 grams of water), and purify by method 3. If you have 1 liter of water left in the flask for 1 kg of meph, then the IPS should be poured in twice as much, and evaporate more, too. But all in a closed system.
5. We put it in freezer, wait for night, get precipitate (practically pure crystallius). Then we rinse it with acetone. Depending on purity, we use 1 or 2 times. Profit.
This method requires neither extra reagents, nor drying, nor long filtration. For 5 kg of meph, you can fit in 8 hours all the stages except the last rinse with acetone. In addition, due to the combination of three cleaning methods and three different solvents (DXM, IPS, acetone) all impurities are washed out much better.
An additional plus is that the solvents (xylene/ benzene/toluene, IPS, acetone) are NOT MIXED and thus can be easily regenerated. Regeneration of solvents I think is a VERY important topic, not at the expense of savings, but at the expense of reduced procurement, and thus the smelliness of the lab, reducing waste - also reduces smelliness. Well, and carry on their own in the fields and woods is also less. Solvents can be regenerated in all methods, with varying success, but in most cases successfully, read the article on the subject - it is also mentioned among the articles at the beginning of this thread.
That's about it. Use it. The process is alive. Thank you.
p.s. I am also actively looking for sponsors for this project.
Last edited:
