Amphetamine Synthesis of 1-phenyl-2-nitropropene (P2NP) from benzaldehyde and nitroethane. Henry's reaction.

[ireshop]

Reaction Scheme:

Laboratory equipment and materials:

• 10 L flask.
• Retort stand and clamp to secure the apparatus (optional).
• Reflux condenser.
• Funnel.
• Vacuum pump.
• Laboratory balance (suitable for 0.1-500 g) - optional.
• 1000 mL and 100 mL measuring cylinders.
• Water bath.
• Glass rod and spatula.
• Filter paper.
• Laboratory thermometer.
• Buchner flask and funnel.
• 5-10 L bucket.
• Freezer.

Reagents:

• Benzaldehyde 1000 ml.
• Nitroethane 1000 ml.
• Glacial acetic acid 250 ml.
• n-Butylamine 50 ml.
• Isopropyl alcohol (IPA) ~1000 ml.

Medium scale:

1. 1000 ml benzaldehyde, 1000 ml nitroethane, 250 ml glacial acetic acid and 50 ml n-butylamine are placed in a 10 L flask.
2. A reflux condenser is installed in the flask.
3. The stirrer and heater are switched on. The reaction mixture is heated to 60 °С.
4. The reaction is carried out for 2-3 hours with constant stirring at 60 °С.
5. The reaction mixture is poured into an empty 5-10 L bucket.
6. 800 ml of IPA is poured into the bucket and stirred.
7. The bucket with the mixture is placed in a freezer for 12 hours, crystallising 1-phenyl-2-nitropropene (P2NP).
8. The P2NP product is filtered through a Buchner funnel (suction filtration procedure), washed with a small amount of cold IPA and air dried (or in a vacuum chamber, optional).

Equipment and glassware:

• 500 ml beaker;
• funnel;
• Vacuum source;
• Laboratory balance (suitable for 0.1-500 g) - optional;
• 50 mL and 100 mL measuring cylinders;
• Glass rod and spatula;
• Filter paper;
• Buchner flask and funnel;
• Freezer;
• 750 W microwave oven;

Reagents:

• Benzaldehyde 100 ml;
• Nitroethane 100 ml;
• Glacial acetic acid 25 ml;
• n-Butylamine 20 ml;
• Isopropyl alcohol (IPA) ~150 ml;

Small scale (microwave):

1. Benzaldehyde 100 ml, nitroethane 100 ml, glacial acetic acid 25 ml and n-butylamine 20 ml are placed in a 500 ml beaker.
2. A rubber glove is placed in the beaker.
3. The beaker is placed in the microwave.
4. The microwave power is set at 750 W. Switch on and heat the mixture to boiling point. It then cools down to room temperature.
5. Repeat step 4 several times. At least 6 times in total.
6. Then 100 ml IPA is added, the reaction mixture is stirred and placed in a freezer for 12 hours. The 1-phenyl-2-nitropropene (P2NP) is crystallised.
7. The P2NP product is filtered through a Buchner funnel (suction filtration procedure), washed with a small amount of cold IPA and air dried (or in a vacuum chamber, optional).

Re-crystallisation of 1-phenyl-2-nitropropene (P2NP) 1-phenyl-2-nitropropene (P2NP) can be recrystallised from hexane, methanol, ethanol or isopropyl alcohol (IPA).