Introduction
This method is posted due to high interest to 5-Cl-ADB-A (MDMB-4en-PINACA) cannabinoid. The method is pretty simple and available for every beginner. The main precursor (MDMB-INACA) can be legally purchased on BB Forum or synthesized by yourself. Synthesis is not take a lot of equipment and can be carried out at home kitchen. Also, an additional extraction method with purification is represented.
Difficulty rating: 1/10
Equipment and glassware:
Difficulty rating: 1/10
Equipment and glassware:
- Beaker 5 L;
- Top stirrer;
- Heating plate;
- Laboratory grade thermometer (0 °C to 100 °C);
- Beakers 5 L; 2L; 500 ml x3;
- Measuring cylinders 1000 ml and 100 ml;
- Plastic bucket 20 L;
- pH indicator paper;
- Laboratory scale (0.1 g-200 g is suitable);
- Filter cloth 300 mesh or Buchner vacuum funnel;
- Crystallization dish for drying the product;
Reagents:
- MDMB-INACA 1000 g (3.46 mol) CAS: 2709672-58-0 (The main precursor);
- DMF (dimethylformamide) 2.5 L;
- 5-Bromo-1-pentene 515 g (409.5 ml; 3.46 mol);
- Potassium carbonate (K2CO3) 750g (5.43 mol);
- Ice ~8 kg;
- Water 2000 ml;
5-CL-ADB-A (MDMB-4en-PINACA) Synthesis From MDMB-INACA (Main Precursor)
Procedures
Pay attention at the synthesis process, when pouring in the bromine the temperature will naturally rise as the reaction is exothermic! You need to wait for the temperature to stabilize before setting it to 80°C to prevent burning!
1. Pour all three ingredients MDMB-INACA 1000 g (3.46 mol), DMF (dimethylformamide) 2.5 L and potassium carbonate (K2CO3) 750g (5.43 mol) into a 5 L beaker, then turn on the top stirrer and mix until a swirl appears in the center. Turn on the heat and set the temperature to 50°C.
1. Pour all three ingredients MDMB-INACA 1000 g (3.46 mol), DMF (dimethylformamide) 2.5 L and potassium carbonate (K2CO3) 750g (5.43 mol) into a 5 L beaker, then turn on the top stirrer and mix until a swirl appears in the center. Turn on the heat and set the temperature to 50°C.
Necessary equipment
2. When the temperature reaches 50°C then pour in the measured 5-bromo-1-pentene 409.5 ml (515 g) slowly;
3. At this time the temperature will rise naturally, because this reaction is exothermic, so don't worry, don't do anything at this time. Check the temperature by thermometer until it no longer rises. When the temperature starts to fall, set the temperature to 80°C.
4. Then the mixture is stirred at 80°C for 5 h.
5. After five hours, turn off all equipment and allow the reaction to cool to room temperature.
6. Ice 8 kg and water 2000 ml are prepared. The cooled reaction solution is poured into the ice water and stirred until a solid appears and continue stirring for 2-3 minutes. Check the mixture pH. It should be ≤ 7.
Ice bucket
7. Then more ice is added and the bucket is put into the fridge, which is set at 2-3°C.
8. After 4 h you can filter out (300 mesh filter or Buchner vacuum funnel) the finished product and then dry it. It’s worth to use vacuum desiccator.
300 Mesh filter and Buchner vacuum funnel
Note: the ice-water reaction mixture after first filtration can be placed into the fridge for a few hours or overnight, more product may crystallize out.
Total yield is quantitative ~1230 g.
Optional Second Extraction Method
This is a solvent-solvent extraction, vacuum distillation, re-crystallization):
1. Once the reaction mixture is cooled to room temperature, add 2x the amount of water to the solution, and add 1L dichloromethane (DCM) while stirring for 10-20 min.
2. Turn off stirring, and let the mixture stand for 15 min, there will be an organic layer and a water layer.
3. The next step is easiest using a large separatory funnel. Pour the water layer into another container, add 800 ml DCM to this, and stir for 10-20 min (or shake the separatory funnel with frequent venting if using a sep funnel), then turn off stirring or stop shaking and let stand for 15 minutes, then remove the water layer leaving you with another organic oil layer
3. Combine the 2 oil layers, add half the amount of water (1:2 - water : oil) and stir for 10 minutes, then turn off stirring and let stand for 30 minutes. Finally remove the water layer.
4. Take the oil layer (contains product) and distill it under vacuum (reduced pressure so you do not overheat). By doing this you will concentrate the oil (product) in the boiling flask, and you will collect/recover the DCM from this oil as the first boiling fraction.
5. Weigh the weight of the oil obtained in the distillation, then add 1.5x that weight of anhydrous ethanol while stirring (should be close to 1.5kg ethanol). If stirring is difficult, heat the mixture slightly.
6. Put the above solution into the freezer for 2 days — stir this solution on the first day of freezing. The ethanol will not freeze as its freezing temperature is under -100°C, far below that of a conventional freezer.
7. Take your solution out of the freezer, there will be a bunch of crystallized final product. Use a 300 mesh filter cloth to filter out the solid, and dry it naturally or under vacuum to get the finished crystalline 5-CL-ADB-A (MDMB-4en-PINACA).
1. Once the reaction mixture is cooled to room temperature, add 2x the amount of water to the solution, and add 1L dichloromethane (DCM) while stirring for 10-20 min.
2. Turn off stirring, and let the mixture stand for 15 min, there will be an organic layer and a water layer.
3. The next step is easiest using a large separatory funnel. Pour the water layer into another container, add 800 ml DCM to this, and stir for 10-20 min (or shake the separatory funnel with frequent venting if using a sep funnel), then turn off stirring or stop shaking and let stand for 15 minutes, then remove the water layer leaving you with another organic oil layer
3. Combine the 2 oil layers, add half the amount of water (1:2 - water : oil) and stir for 10 minutes, then turn off stirring and let stand for 30 minutes. Finally remove the water layer.
4. Take the oil layer (contains product) and distill it under vacuum (reduced pressure so you do not overheat). By doing this you will concentrate the oil (product) in the boiling flask, and you will collect/recover the DCM from this oil as the first boiling fraction.
5. Weigh the weight of the oil obtained in the distillation, then add 1.5x that weight of anhydrous ethanol while stirring (should be close to 1.5kg ethanol). If stirring is difficult, heat the mixture slightly.
6. Put the above solution into the freezer for 2 days — stir this solution on the first day of freezing. The ethanol will not freeze as its freezing temperature is under -100°C, far below that of a conventional freezer.
7. Take your solution out of the freezer, there will be a bunch of crystallized final product. Use a 300 mesh filter cloth to filter out the solid, and dry it naturally or under vacuum to get the finished crystalline 5-CL-ADB-A (MDMB-4en-PINACA).