This video demonstrates a simple way to make a small amount of mephedrone. Reagents were used in the synthesis:
4-methylpropiophenone - 100g
Benzene – 600ml
Bromine - 100g
N-methylpyrrolidone - 300ml
Methylamine 40% (aqueous solution) - 200 ml
Hydrochloric Acid 35% - 55ml
Acetone - 1000ml
Description of the mephedrone synthesis video:
From 0:00 to 0:48
At the beginning of the video, it is said that the temperature of the room and reagents (except for those that need to be cooled) should be moderate, about 20-25ºC.
Next, the preparation of the reactor to work is described:
"The 2000ml, flask is mounted on a magnetic stirrer and secured to a tripod. Check that the magnet is working correctly. Place a reflux condenser in the central neck and fit a gas outlet hose to it. Place the hose carefully, without kinks, into a canister with 15% aqueous sodium bicarbonate solution (to absorb odours)."
Then comes the loading of the reagents:
"Pour 100g of 4-methylpropiophenone and 300ml of benzene into the flask and stir. Pour 100g of bromine and 100ml of benzene into the dropping funnel. Place a thermometer and a bromine dropping funnel in the sides of the funnel. Turn on gentle heating and wait until the temperature in the reactor reaches 35ºC, then turn off the heating."
From 0:48 to 3:23
Bromination reaction. After loading the reagents, the lab technician begins bromination. In small portions, he adds a solution of bromine in benzene to the flask, so that the reaction mixture has time to discolour. After all the bromine has been poured in, the mixture is spun on a magnetic stirrer for another 30 minutes.
"After switching off the heat, add the bromine to the mixture in four roughly equal portions, drop by drop. Each portion is added after the previous one has discoloured."
"When all the bromine has been poured in, leave it to stir for another 30 minutes."
Bromination of 4-Methylpropiophenone results in 2-Bromo-4-Methylpropiophenone in benzene.
From 3:23 to 6:16
The lab technician washes the resulting solution with water in a separating funnel, draining excess pressure through a tap. He twists the funnel in a circular motion, thus collecting the remaining water and draining it, leaving the solution of 2-Bromo-4-Methylpropiophenone in benzene for the next synthesis.
"After 30 minutes, add 200 ml of water."
"Pour the mixture into the separating funnel. Allow the layers to separate clearly. Dispose of the bottom layer, work to the top layer."
"Repeat the rinse. Pour 200 ml of water, shake well. Allow the layers to separate clearly. Drain the bottom layer.
Do not forget to release the pressure by opening the valve."
"Rotate the funnel in a circular motion to collect all the water downwards."
From 6:17 to 9:02
Methylamination reaction. The lab technician places a solution of 2-Bromo-4-Methylpropiophenone in benzene back into the flask, pours in methylamine. Heats the reaction mixture to 40 degrees. Starts adding NMP in small portions, making sure the temperature does not exceed 60ºC. If the temperature gets higher, wait for the temperature to drop before adding the next batch of NMP. After all NMP has been added, the reaction mixture is left to stir for 15 minutes. During the methylamination process, a rich amber color of the reaction mixture can be observed: this is a sign that the reaction has passed.
Methylamination of 2-Bromo-4-Methylpropiophenone gives mephedrone free base (4MMC).
"Pour the obtained 2-Bromo-4Methylpropiophenone in benzene back into a clean flask and add 200ml of 40% methylamine (aqueous solution)."
"Attach a reflux condenser, funnel and thermometer to the flask. Turn on stirring and heat to 40ºC."
"When the temperature has reached 40ºC, turn off the heat and add 300ml of N-methylpyrrolidone from the dropping funnel, making sure that the temperature does not exceed 60ºC. After adding N-methylpyrrolidone a short exothermic reaction takes place and the temperature may rise."
"Once all the N-methylpyrrolidone has been poured in, leave it to stir for 15 minutes."
From 9:03 to 11:33
Washing out the free base of mephedrone. The lab technician washes the free base with 200ml 5% sodium bicarbonate solution and 3 times 200ml water. Shakes the mixture well, venting through a valve. Clearly separates the layers in the separating funnel. Drain the lower aqueous layer into the waste, and the upper organic layer with a free base is left for further work. The lab technician adds a pinch of sodium chloride to remove residual water in the form of turbidity. After stirring well, he lets it stand and drains the water residue. The output is pure free mephedrone base.
"Then add 100ml 5% sodium hydrocarbonate solution and 200ml benzene. Stir well. Pour into a separating funnel and allow the layers to separate clearly."
"The lower water layer is disposed of"
"To the free base of mephedrone in benzene (top layer) pour 200ml of water, stir well and let the layers separate clearly. The lower aqueous layer disposes of."
"Rinse the free base of mephedrone in benzene with water three times."
"If the base of the mephedrone in the benzene looks cloudy after rinsing, pour some sodium chloride over it and stir in a circular motion."
"Allow to stand for a couple of minutes, the rest of the water with the sodium chloride will collect at the bottom of the funnel. Dispose of this water residue. A clear clear free mephedrone base in benzene will remain in the funnel."
From 11:34 to 12:38
Acidification. In this part of the synthesis, the lab technician converts the mephedrone base to a hydrochloride salt. He adds hydrochloric acid drop by drop to the free base of 4MMC and stirs constantly. When the mixture is acidified, it heats up and a precipitate appears, which is mephedrone. During the acidification, it is necessary to constantly measure the Ph. When the pH level of 5-5.5 is reached, the acidification is stopped, the glass with the mixture is covered with film and put in the freezer for a few hours.
"Pour the mephedrone base in benzene into a wide beaker, put it on a magnetic stirrer, place a magnet and start stirring. Place a dropping funnel above the beaker and add 55 ml of hydrochloric acid at 1-2 drops per second."
"Measure the pH value every 10 seconds; acidify to a pH of 5-5.5. In the process of acidification, mephedrone will form in the glass and the temperature will rise. The mephedrone may dissolve, this is normal, it will appear later on cooling."
"When the pH has reached 5-5.5, turn off the stirring, cover the glass with clingfilm and put it in the freezer for 4 hours. The freezer temperature should not exceed -15ºC."
From 12:39 to
Filtration and cleaning.
In the final part of the video, the lab technician prepares the apparatus for filtration: a Buechner funnel with a paper filter is placed on a Bunsen flask. The filter is moistened with acetone for better contact with the surface of the funnel. The mixture is stirred well so that the precipitate does not stick to the beaker and poured into the funnel. The remainder of the mephedrone is washed off with an additional portion of acetone and transferred to a Buechner funnel.
Then a vacuum pump is connected to the Bunsen flask via a hose. During the filtration process, the powder thickens slightly and the cracks are smoothed out. For better cleaning, a small amount of acetone is added to the Buechner funnel, simultaneously switching off the vacuum. They rinse with acetone until transparent flushes drip from the funnel.
After washing with acetone, the powder is dried in a Buechner funnel with the vacuum switched on until it is crumbly. The mephedrone is finish air dried in a dry room and weighed.
"The resulting precipitate is filtered under vacuum and washed on the filter with acetone, smoothing out the cracks.
Unfold the long edge of the funnel spout in the opposite direction from the side outlet of the flask."
"Be sure to moisten the filter with acetone."
"Wash off any residue of mephedrone powder in the glass with acetone."
"Hose from a vacuum pump."
"Magnet from a magnetic stirrer."
"Dry the mephedrone on the air. The theoretical yield of mephedrone hydrochloride from 100g of 4-methylpropiophenone is 144g, but considering losses, you get ~100g (maybe more)."