Reaction scheme:
Reagents:
Equipment and glassware:
1. 2-Bromo-4'-methylpropiophenone 5 kg is poured into Batch reactor or another crude 2-Bromo-4'-methylpropiophenone amount after halogenation reactions.
2. n-Methyl-2-pyrrolidone 20 L is poured into the reactor. Top stirrer is turned on and the reaction mixture is heated up to 40 °С.
3. When temperature is reached 40 °С, methylamine 40% aq. solution 8 L is poured into the reaction mixture and stirred for 20 min.
4. Next, distilled cold water 20 L is poured into reaction mixture and stirred for few minutes.
5. Benzene 15-20 L or other suitable solvent is poured into the reactor, the mixture is stirred for few minutes.
6. Than, the stirrer is stopped, the mixture is divided into two layers.
7. The bottom aqueous layer is drained through the bottom valve of the reactor. Top layer is drained into a bucket and dried over MgSO4. Than, dry solution is poured in another bucket.
8. Ice acetone 20 L is added to the reaction mixture and hydrochloric acid (HCl 36%) is added dropwise with a constant stirring to reach pH 5.5-6.
9. The mixture is put into a freezer for 12 h.
10. Crystallized mephedrone hydrochloride is filtered on a Nutsche filter and air dried. The yield is 58%.
Note
NMP can be replaced by DMSO, DMF, Sulfolane.
Reagents:
- 2-Bromo-4'-methylpropiophenone (cas 1451-82-7) - 5 kg;
- n-Methyl-2-pyrrolidone (NMP; cas 872-50-4) - 20 L;
- Methyl amine 40% aq. solution (cas 74-89-5) - 8 L;
- Benzene - 20 L;
- Acetone - 30 L;
- Hydrochloric acid con. aq. solution (HCl 36%) ~ 1.5 L;
- Distilled water - 20 L;
- Magnesium sulphate (MgSO4);
Equipment and glassware:
- 100 L Batch reactor, which is equipped with drip funnel, top stirrer, thermometer, temperature control system (cooling) and reflux condenser;
- Funnel;
- pH indicator papers;
- Several buckets 25 L;
- Barrel 100 L;
- Beaker 2000 mL;
- Vacuum source;
- Scale;
- Measuring cylinder 1000 mL;
- Glass rod and spatula;
- Scoops;
- Nutsche filter;
- Rotary evaporator;
Synthesis procedures1. 2-Bromo-4'-methylpropiophenone 5 kg is poured into Batch reactor or another crude 2-Bromo-4'-methylpropiophenone amount after halogenation reactions.
2. n-Methyl-2-pyrrolidone 20 L is poured into the reactor. Top stirrer is turned on and the reaction mixture is heated up to 40 °С.
3. When temperature is reached 40 °С, methylamine 40% aq. solution 8 L is poured into the reaction mixture and stirred for 20 min.
4. Next, distilled cold water 20 L is poured into reaction mixture and stirred for few minutes.
5. Benzene 15-20 L or other suitable solvent is poured into the reactor, the mixture is stirred for few minutes.
6. Than, the stirrer is stopped, the mixture is divided into two layers.
7. The bottom aqueous layer is drained through the bottom valve of the reactor. Top layer is drained into a bucket and dried over MgSO4. Than, dry solution is poured in another bucket.
8. Ice acetone 20 L is added to the reaction mixture and hydrochloric acid (HCl 36%) is added dropwise with a constant stirring to reach pH 5.5-6.
9. The mixture is put into a freezer for 12 h.
10. Crystallized mephedrone hydrochloride is filtered on a Nutsche filter and air dried. The yield is 58%.
Note
NMP can be replaced by DMSO, DMF, Sulfolane.
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