Synthesis of phenylnitropropene at home: it couldn't be easier
The main precursor for amphetamine synthesis is phenylnitropropene.
Phenylnitropropene is very easy to synthesize, which makes this method of amphetamine synthesis the most popular among chemists.
The synthesis will require:
- Flask (glass bottle)
- Reflux condenser
- Electric stove (for water bath)
The proportions of the substances are scaled in multiples, but it is recommended not to fill the reactor more than 2/3 of its volume.
The required proportions for a 1L flask are:
- Benzaldehyde - 200ml.
- Nitroethane - 200ml
- n-Butylamine - 20 ml
- Glacial acetic acid (GAA) - 50 ml
- Isopropyl alcohol (IPA)
The reaction is sensitive to water, so it is desirable to keep the reagents as dry as possible.
Add benzaldehyde, nitroethane, catalyst, and GAA to the flask, stir well, and place on a hotplate. Place over low heat and heat to 60ºC while stirring. You can use a water bath for heating. The temperature in the reactor can be controlled with a thermometer or by touch. The flask should be quite hot to the touch, but there should be no burning of your hand. Cooling is not required for this synthesis, you can simply turn off the heat for a while until the temperature returns to the desired parameters (~60ºC). It is necessary to stir periodically during the reaction, the synthesis time is 3-4 hours. During the reaction, the color changes from light yellow to dark red and remains clear. Then the reaction mixture is cooled to room temperature, poured into a glass or jar, diluted with 250 ml of warm water, covered with a lid and placed in the freezer for 2 hours. When cooled, open the lid and shake gently, allowing fresh air to circulate.
Crystallization occurs rapidly. The jar with crystals is again kept in the freezer for at least 15 minutes. Then you need to break the crystals and wash them with cold water until the traces of vinegar disappear (2...3 times is enough). Then rinse with small amounts of very cold isopropyl alcohol until impurities are removed. The resulting crystals are then dried in the air for a minimum of 10 hours. Store phenylnitropropene in a closed container in the refrigerator or dark, cool place.
Important to know!
- Flushing with isopropyl alcohol should be performed at the lowest possible temperature. This will reduce losses.
- Place isopropyl alcohol in the freezer for 8 hours prior to use.
- Rinse until the filtrate becomes colorless.
- It is convenient to use an ordinary thin cloth as a filter because the crystals are quite large.
- Phenylnitropropene has an unpleasant pungent odor and is corrosive to skin on the hands and face.
- The darker the phenylnitropropene, the more impurities it contains.
Phenylnitropropene can be recrystallized from isopropyl alcohol just before starting the following reaction.
For this purpose, phenylnitropropene crystals are dissolved in isopropyl alcohol at 30ºC and the solution is brought to supersaturation. Then freeze at the lowest possible temperature until crystallization is complete. Filtered when crystallization is complete.
Phenylnitropropene dries in air, It is not hygroscopic (does not absorb water from the air).
Average yield is 300 grams (~70% of theoretical yield).
Watch the phenylnitropropene synthesis video tutorial for a full understanding:
https://bbgate.com/threads/1-phenyl-2-nitropropene-p2np-video-synthesis-from-benzaldehyde-and-nitroethane-henry-reaction.52/
https://bbgate.com/threads/1-phenyl-2-nitropropene-p2np-video-synthesis-from-benzaldehyde-and-nitroethane-henry-reaction.52/
