The following reagents are used:
A solution of 10 g of 1-phenyl-2-nitropropene in 100 ml isopropyl alcohol and 50 ml acetic acid is prepared before starting the synthesis. In addition, 12 g of aluminum foil is cut into small pieces with a paper shredder for the preparation of an aluminum amalgam. It can be cut with scissors or torn with hands (wearing gloves).
- Preparation of an aqueous alkaline solution. This solution was made in advance so that it has room temperature at the time of alkalinization of the main reaction mixture in this video. The alkalinization is carried out with spontaneous heating. If a freshly made hot aqueous alkaline solution is used, then the temperature will rise further and forced cooling of the reaction mass will be necessary.
- Amalgamation with mercury nitrate. The amalgamated aluminum will reduce 1-phenyl-2-nitropropene to amphetamine. During the amalgamation reaction a small amount of gas is evolved, forming a gray precipitate. It is important not to miss the moment when the aluminum amalgam is ready. This moment can be determined by the formation of a gray precipitate and by an increase in gas evolution. This occurs within 10-15 minutes from the start of the reaction.
- The water is drained without removing the gauze, the amalgamated aluminum is washed with two portions of cold distilled water. It is worth paying attention to the release of gas bubbles. It is noted that the bubbles are smaller and the color of the liquid is darker in a "correct" amalgam. If the reaction is violent, the bubbles are large and the color is light, the amalgam is "incorrect". This is almost certainly due to a lack of mercury salt. Note that mercury salts are poisonous.
- The most important part of the process is the reduction of 1-phenyl-2-nitropropene by the aluminum amalgam. The reaction is exothermic and is carried out with an abundant release of heat. It is necessary to carefully control the temperature during the procedure. If overheating occurs, the reaction flask is cooled in an ice bath. It is allowed to add cold water to the flask. Sometimes the reaction does not start, it is necessary to heat the reaction mass well and then start the reaction (with a properly prepared amalgam). Odors of boiling alcohol and acetic acid are released during the reaction. An Allihn reflux condenser is used to capture the vapors. The efficiency of the Allihn reflux condenser can be increased with running cold water, which can be connected to it.
- The reaction flask can be rinsed with a small amount of alcohol and the unreacted aluminum can also be rinsed to collect residues and increase the yield.
- There should be little unreacted aluminum left. You can determine the amount of 1-phenyl-2-nitropropene reacted by the residues.
- Alkalinization. The reaction is carried out with heat release. Unreacted aluminum residues will additionally react with alkali and heat the mixture as well as create by-products. A separation into visible layers occurs within 30 minutes after alkalinization. The pH of the top layer should be 11-12.
- Decanting. The top layer is collected with amphetamine base in alcohol. It can be dried with a small amount of anhydrous magnesium sulfate. The scum can be extracted with a nonpolar solvent (ether, benzene, toluene), then the solvent is evaporated.
- Preparation of the sulfuric acid solution in acetone. This solution is necessary for a milder acidification. If concentrated sulfuric acid is used, local overacidification of the product occurs. Therefore, the yield decreases.
- Acidification of the product and obtaining amphetamine sulfate. To the yellow top layer, which was collected in the previous step, a prepared solution of sulfuric acid is added dropwise. With each drop of acid solution salt flakes are formed. This stage is very important, it is necessary to carefully control the pH to avoid overacidification. Acidification continues up to a pH of 5.5-6. The overacidified product has a pinkish color. The product will spoil in case of total overacidification.
- Filtration of the amphetamine sulfate from the solvents in a Büchner funnel under vacuum. The product can be additionally rinsed with cold acetone at this stage by pouring it through the Büchner funnel with the amphetamine sulfate cake.
- Filtration using improvised tools. Any coarse cloth can be used as a filter. The resulting product is dried in a warm, dry place for several hours to remove residual solvents. It is recommended to store it in a vacuum package.
The yield is 60-70%.
- 10 g of 1-Phenyl-2-nitropropene (P2NP)
- 100 ml of isopropyl alcohol (IPA)
- 50 ml of glacial acetic acid (AcOH)
- 50 g sodium hydroxide (NaOH)
- 12 g aluminum (in the form of household aluminum foil sheets)
- 0.1 g of mercury (II) nitrate (Hg(NO3)2)
- 2 ml of sulfuric acid (H2SO4)
- 50 ml of acetone
- Distilled water
- 2 L flat bottom flask
- Retort holder and clamp for securing the apparatus (optional)
- Reflux condenser
- Funnel
- Sieve filter (kitchen grade is fine)
- Pasteur syringe or pipette
- pH indicator papers
- Beakers (600 mL x2, 2 L, 1 L, 100 mL x2)
- Vacuum pump
- Laboratory balance (0.1-200 g is suitable)
- Measuring cylinders of 1000 mL and 100 mL
- Cold water bath
- Glass rod and spatula
- 1 L separatory funnel (optional)
- Laboratory grade thermometer
- Büchner flask and funnel
- Filter paper
A solution of 10 g of 1-phenyl-2-nitropropene in 100 ml isopropyl alcohol and 50 ml acetic acid is prepared before starting the synthesis. In addition, 12 g of aluminum foil is cut into small pieces with a paper shredder for the preparation of an aluminum amalgam. It can be cut with scissors or torn with hands (wearing gloves).
- Preparation of an aqueous alkaline solution. This solution was made in advance so that it has room temperature at the time of alkalinization of the main reaction mixture in this video. The alkalinization is carried out with spontaneous heating. If a freshly made hot aqueous alkaline solution is used, then the temperature will rise further and forced cooling of the reaction mass will be necessary.
- Amalgamation with mercury nitrate. The amalgamated aluminum will reduce 1-phenyl-2-nitropropene to amphetamine. During the amalgamation reaction a small amount of gas is evolved, forming a gray precipitate. It is important not to miss the moment when the aluminum amalgam is ready. This moment can be determined by the formation of a gray precipitate and by an increase in gas evolution. This occurs within 10-15 minutes from the start of the reaction.
- The water is drained without removing the gauze, the amalgamated aluminum is washed with two portions of cold distilled water. It is worth paying attention to the release of gas bubbles. It is noted that the bubbles are smaller and the color of the liquid is darker in a "correct" amalgam. If the reaction is violent, the bubbles are large and the color is light, the amalgam is "incorrect". This is almost certainly due to a lack of mercury salt. Note that mercury salts are poisonous.
- The most important part of the process is the reduction of 1-phenyl-2-nitropropene by the aluminum amalgam. The reaction is exothermic and is carried out with an abundant release of heat. It is necessary to carefully control the temperature during the procedure. If overheating occurs, the reaction flask is cooled in an ice bath. It is allowed to add cold water to the flask. Sometimes the reaction does not start, it is necessary to heat the reaction mass well and then start the reaction (with a properly prepared amalgam). Odors of boiling alcohol and acetic acid are released during the reaction. An Allihn reflux condenser is used to capture the vapors. The efficiency of the Allihn reflux condenser can be increased with running cold water, which can be connected to it.
- The reaction flask can be rinsed with a small amount of alcohol and the unreacted aluminum can also be rinsed to collect residues and increase the yield.
- There should be little unreacted aluminum left. You can determine the amount of 1-phenyl-2-nitropropene reacted by the residues.
- Alkalinization. The reaction is carried out with heat release. Unreacted aluminum residues will additionally react with alkali and heat the mixture as well as create by-products. A separation into visible layers occurs within 30 minutes after alkalinization. The pH of the top layer should be 11-12.
- Decanting. The top layer is collected with amphetamine base in alcohol. It can be dried with a small amount of anhydrous magnesium sulfate. The scum can be extracted with a nonpolar solvent (ether, benzene, toluene), then the solvent is evaporated.
- Preparation of the sulfuric acid solution in acetone. This solution is necessary for a milder acidification. If concentrated sulfuric acid is used, local overacidification of the product occurs. Therefore, the yield decreases.
- Acidification of the product and obtaining amphetamine sulfate. To the yellow top layer, which was collected in the previous step, a prepared solution of sulfuric acid is added dropwise. With each drop of acid solution salt flakes are formed. This stage is very important, it is necessary to carefully control the pH to avoid overacidification. Acidification continues up to a pH of 5.5-6. The overacidified product has a pinkish color. The product will spoil in case of total overacidification.
- Filtration of the amphetamine sulfate from the solvents in a Büchner funnel under vacuum. The product can be additionally rinsed with cold acetone at this stage by pouring it through the Büchner funnel with the amphetamine sulfate cake.
- Filtration using improvised tools. Any coarse cloth can be used as a filter. The resulting product is dried in a warm, dry place for several hours to remove residual solvents. It is recommended to store it in a vacuum package.
The yield is 60-70%.
