The reactions proceed according to Scheme 1.
Aluminum foil is placed into a 2 L flask and filled with water, ensuring that the foil is submerged beneath the water layer. Fig 1
Dry mercury(II) chloride is added, and vigorous stirring is performed until hydrogen is actively evolved and a dull appearance appears on the foil. Fig 2
Fig 3
Fig 4
Next, the solution is drained, and the aluminum amalgam is washed twice with distilled water. Fig 5
Ice-cold water should be prepared in advance for cooling the flask. To the obtained aluminum amalgam, methylamine, sodium chloride solution, P2P, and IPA are added. The reflux condenser is connected to the flask, and an exothermic reaction begins after approximately 20-30 minutes. Fig 6
Fig 7
Fig 8
The reactor should be cooled if the temperature exceeds 50-60°C. Fig 9
Fig 10
Fig 11
The reaction proceeds completely in approximately 3 hours, during which the reagents transform into a gray mass. Fig 12
To the reaction mass, 10 mL of 25% NaOH is added to dissolve any unreacted aluminum. The mixture is then allowed to stand for 30-40 minutes until the evolution of hydrogen ceases. Fig 13
Fig 14
The solution is separated from the precipitate through filtration, decantation, or centrifugation. The precipitate is further washed with ethanol or IPA to extract the Methamphetamine. Fig 15
Fig 16
The obtained Methamphetamine solution is extracted with several portions of dichloromethane. Fig 17
Fig 18
The dichloromethane layer is separated using a separatory funnel. If there is an excess of other solvents such as ethanol and isopropanol, there may be a significant increase in volume. In such cases, the organic layer is washed with water to remove the alcohols. Sometimes, it can be challenging to determine the location of the organic (target) layer and the aqueous layer due to their different densities. To determine the location of the target layer, a drop of the solution can be taken with a pipette and rubbed between the fingers. The organic layer (DCM) will almost instantly dry, leaving a pleasant odor of the formed amine, which is distinct from the strong smell of methylamine. The aqueous layer will have a strong alkaline reaction and give a soapy feeling between the fingers when rubbed. The separated DCM layer, if necessary, is filtered and further dried with anhydrous sodium sulfate. Fig 19
Layer of Methamphetamine extract in dichloromethane after drying with anhydrous sodium sulfate. Fig 20
The dried dichloromethane layer is transferred to a setup for distillation using a water bath. At a temperature of 90°C, the entire dichloromethane is evaporated and distilled off. Fig 21
Fig 22
After the distillation process, the flask contains the Methamphetamine free base with its characteristic odor. Fig 23
The obtained free base Methamphetamine is filtered through a paper filter, and the filter is additionally rinsed with ethanol. Fig 24
Next, a stream of gaseous hydrogen chloride is passed into the solution of the Methamphetamine in ethanol. Hydrogen chloride gas can be generated by slowly dripping sulfuric acid onto ammonium chloride. Fig 25
Fig 26
Fig 27
During this process, the color of the solution should change from yellow to a rich pink, which is indicative of the formation of the desired Methamphetamine. Fig 28
Fig 29
Fig 30
Fig 31
Fig 32
Fig 33
The obtained solution is evaporated until crystallization occurs. Fig 34
Fig 35
Fig 36
Fig 37
The crystallized mass is placed on a filter and washed with several minimal possible portions of diethyl ether. Fig 38
Fig 39
Fig 40
Next, the mass is quickly washed with acetone, filtered, and dried on the filter. Fig 41
Fig 42
From 10 g of P2P, it should yield 13.84 g of Methamphetamine hydrochloride, which corresponds to a 100% yield, assuming complete conversion and maximum product formation.
The yield in this experiment is as follows:
10.2 g or 73% after washing with diethyl ether
9.6 g or 69% after washing with acetone.
Reagents and materials:
- Aluminum foil, 14 µm, 10.5 g
- Mercury(II) chloride, 0.1 g
- Distilled water, 3 L
- P2P (phenyl-2-propanone), 10 g
- Methylamine 39%, 25-30 mL
- Sodium chloride, 10 g in 30 mL water
- Isopropylalcohol (IPA), 150 mL
- Dichloromethane, 150-200 mL
- Ethanol 88%, 25 mL
- Ammonium chloride, 50-100 g
- Concentrated sulfuric acid 80%, 15 mL
- Technical-grade water, 2 L with 500 g of ice
- Anhydrous sodium sulfate, 20-30 g
- 10 mL 25% NaOH (sodium hydroxide)
- Diethyl ether, 15 mL
- Acetone, 20-25 mL
- 2 L flask, 500 mL flask, 250 mL flask
- Three-necked flask, 500 mL, for hydrogen chloride generation
- Distillation setup
- Reflux condenser
- Vacuum filtration setup
- Separatory funnel
- Silicone grease
- Filter paper
- Funnel
- Beakers
- Heater
Stage 1. Preparation of Aluminum Amalgam
Aluminum foil is placed into a 2 L flask and filled with water, ensuring that the foil is submerged beneath the water layer. Fig 1Dry mercury(II) chloride is added, and vigorous stirring is performed until hydrogen is actively evolved and a dull appearance appears on the foil. Fig 2
Fig 3
Fig 4
Next, the solution is drained, and the aluminum amalgam is washed twice with distilled water. Fig 5
Stage 2. Reduction and Extraction
Ice-cold water should be prepared in advance for cooling the flask. To the obtained aluminum amalgam, methylamine, sodium chloride solution, P2P, and IPA are added. The reflux condenser is connected to the flask, and an exothermic reaction begins after approximately 20-30 minutes. Fig 6Fig 7
Fig 8
The reactor should be cooled if the temperature exceeds 50-60°C. Fig 9
Fig 10
Fig 11
The reaction proceeds completely in approximately 3 hours, during which the reagents transform into a gray mass. Fig 12
To the reaction mass, 10 mL of 25% NaOH is added to dissolve any unreacted aluminum. The mixture is then allowed to stand for 30-40 minutes until the evolution of hydrogen ceases. Fig 13
Fig 14
The solution is separated from the precipitate through filtration, decantation, or centrifugation. The precipitate is further washed with ethanol or IPA to extract the Methamphetamine. Fig 15
Fig 16
The obtained Methamphetamine solution is extracted with several portions of dichloromethane. Fig 17
Fig 18
The dichloromethane layer is separated using a separatory funnel. If there is an excess of other solvents such as ethanol and isopropanol, there may be a significant increase in volume. In such cases, the organic layer is washed with water to remove the alcohols. Sometimes, it can be challenging to determine the location of the organic (target) layer and the aqueous layer due to their different densities. To determine the location of the target layer, a drop of the solution can be taken with a pipette and rubbed between the fingers. The organic layer (DCM) will almost instantly dry, leaving a pleasant odor of the formed amine, which is distinct from the strong smell of methylamine. The aqueous layer will have a strong alkaline reaction and give a soapy feeling between the fingers when rubbed. The separated DCM layer, if necessary, is filtered and further dried with anhydrous sodium sulfate. Fig 19
Layer of Methamphetamine extract in dichloromethane after drying with anhydrous sodium sulfate. Fig 20
Stage 3. Extraction of the Methamphetamine free base and obtaining its hydrochloride.
The dried dichloromethane layer is transferred to a setup for distillation using a water bath. At a temperature of 90°C, the entire dichloromethane is evaporated and distilled off. Fig 21Fig 22
After the distillation process, the flask contains the Methamphetamine free base with its characteristic odor. Fig 23
The obtained free base Methamphetamine is filtered through a paper filter, and the filter is additionally rinsed with ethanol. Fig 24
Next, a stream of gaseous hydrogen chloride is passed into the solution of the Methamphetamine in ethanol. Hydrogen chloride gas can be generated by slowly dripping sulfuric acid onto ammonium chloride. Fig 25
Fig 26
Fig 27
During this process, the color of the solution should change from yellow to a rich pink, which is indicative of the formation of the desired Methamphetamine. Fig 28
Fig 29
Fig 30
Fig 31
Fig 32
Fig 33
The obtained solution is evaporated until crystallization occurs. Fig 34
Fig 35
Fig 36
Fig 37
The crystallized mass is placed on a filter and washed with several minimal possible portions of diethyl ether. Fig 38
Fig 39
Fig 40
Next, the mass is quickly washed with acetone, filtered, and dried on the filter. Fig 41
Fig 42
From 10 g of P2P, it should yield 13.84 g of Methamphetamine hydrochloride, which corresponds to a 100% yield, assuming complete conversion and maximum product formation.
The yield in this experiment is as follows:
10.2 g or 73% after washing with diethyl ether
9.6 g or 69% after washing with acetone.
Fig 43
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Please make a report on the synthesis of p2p from butanone and benzaldehyde