Check if it's correct - pro chemists only

[mikegoodman]

Step-by-Step Recipe​

Initial Setup​

1. Prepare the Solvent Mixture:
   • Measure 25 mL of Isopropyl Alcohol (IPA) (5 times the weight of P2NP).
   • Add 5 mL of distilled water (20% of the total volume of IPA).
2. Mark Liquid Level:
   • Mark the liquid level on the side of the reaction vessel for future reference.
3. Start Stirring:
   • Turn on the stirring apparatus to medium speed.

Reduction Reaction​

1. Add Sodium Borohydride:
   • Weigh 6.87 g of granular sodium borohydride (6 molar equivalents based on 5 g of P2NP).
2. Add P2NP:
   • Gradually add 5 g of P2NP in small portions to control frothing and temperature.
3. Monitor the Reaction:
   • Continue stirring until the yellow solution decolorizes, indicating the reduction is progressing.
4. Top Up with IPA:
   • If necessary, add additional IPA to maintain the initial liquid level.
5. Add More Sodium Borohydride:
   • Add an additional 2.29 g of sodium borohydride (2 molar equivalents).

Addition of Copper Chloride Dihydrate​

1. Prepare Copper Chloride Solution:
   • Dissolve 0.93 g of CuCl2·2H2O (18% molar equivalent) in a small amount of distilled water.
2. Add Copper Chloride Solution:
   • Add the solution in one go with vigorous overhead stirring.
3. Allow Reaction to Complete:
   • Continue stirring for 40 minutes to allow the formation of the copper nanoparticle catalyst and reduction of the nitro group to the amine group.

Quenching and Distillation​

1. Quench the Reaction:
   • Slowly add a dilute acetic acid solution until the pH reaches 3.
2. Distillation Setup:
   • Set up a short path distillation apparatus and distill off everything up to 96°C to remove the IPA.

Extraction of Amine​

1. Adjust pH with NaOH:
   • Add 25% NaOH solution until the pH reaches 12.
2. Steam Distillation:
   • Set up for steam distillation using a vertical steam head connected to a wallpaper steamer filled with deionized water.
   • Distill directly into a 2L separatory funnel connected to a condenser.
   • If the funnel becomes more than 75% full, drain off some water.
3. Collect Amine:
   • Collect the clear amine oil that floats on top of the water.

Salting Out and Drying​

1. Salt Out the Aqueous Layer:
   • Return the water to the separatory funnel and add enough NaCl to saturate it (around 350 g/L).
   • Shake well and allow to settle for a few hours.
   • Separate the aqueous and organic layers again.
2. Combine Organic Extracts:
   • Combine the organic amine extracts and dry over molecular sieves (3A) for 6 hours.
3. Filter:
   • Filter out the molecular sieves to obtain the dried amine oil.

Final Reaction to Form Amphetamine Sulfate​

1. Prepare Amine-IPA Mixture:
   • Mix the amine oil with an equal volume of dry IPA.
2. Calculate and Add Sulfuric Acid:
   • Calculate the amount of H2SO4 needed based on your yield (e.g., 0.06 moles of H2SO4, which equals 5.88 g).
   • Dilute the sulfuric acid in twice its volume of dry IPA and add dropwise to the amine-IPA mixture until pH 7.
3. Crystallization:
   • Filter the resulting amphetamine sulfate using a Buchner funnel and vacuum.
   • Test the filtrate for pH and adjust if necessary by adding more acid dropwise until pH 7.
4. Final Filtration:
   • Leave the crystal slurry in a cold fridge overnight, then filter again on the Buchner funnel.
5. Dry the Product:
   • Allow the amphetamine sulfate to dry completely, yielding a white amorphous solid.

 

[HerrHaber]

This was planned by someone who learned the method really well but has only little practical experience since for 5g p2np too much attention and unnecessary procedures are involved. It's much easier to reduce with aluminium amalgam on this scale and the product is much more appreciated. For short, this is well planned but I know you will loose a lot with this lengthy purification so this isn't scale optimized. Molecular sieves may be useful in other contexts but here anhydrous MgSO4 is your friend or Na2SO4 just not CaCl2 for this particular synthesis. 4A sieves are more recommended but they are too expensive in contrast with MgSO4. This prep. procedure is rather applicable starting with 50g p2np to make more sense.