Introduction
In this article, a detailed description of d-methamphetamine hydrochloride synthesis via tartaric acid was represented. This isomer separation approach is the easiest and most popular among clandestine chemists. It's reasoned by cheap and affordable d,l-Tartaric acid (CAS 133-37-9) and plain equipment, used in this laboratory manipulations.
The approach is consist of:
The approach is consist of:
- A Steam Distillation of Additional Methamphetamine Free Base Portions from the Main Synthesis Mother Liquors;
- Dextromethamphetamine Hydrochloride Formation;
- Recrystallization of d-Methamphetamine Hydrochloride;
Equipment and glassware:
- A 2 L distillation flask;
- A magnetic stirrer with a heater;
- 1 L and 250 ml Distillation flasks;
- Funnel;
- Filter paper;
- 1 L x3, 500 ml x2 Beakers;
- 1 L three-necked flask;
- Electric stove;
- PTFE hoses;
- pH Indicator paper;
- 250 mL Separatory funnel;
- Measuring cylinder;
- Freezer;
- Circulating pump chiller (optional);
- Pyrex dishes for product (or other containers);
- Schott vacuum filtration system;
Reagents:
- Aqueous methamphetamine hydrochloride solutions 300 g;
- Sodium hydroxide (NaOH) 200 g;
- Water 850 ml;
- d,l-Tartaric acid (CAS 133-37-9) 128 g;
- Ethanol 88% 870 ml;
- Ammonium chloride (NH4Cl);
- Diethyl ether (Et2O);
- Sulfuric acid;
A Steam Distillation of Additional Methamphetamine Free Base Portions From the Main Synthesis Mother Liquors
1. A 2 L distillation flask is installed onto a magnetic stirrer with a heater.
2. Aqueous methamphetamine hydrochloride solutions 300 g with side products, obtained from the mother liquids after removal of organic solvents (ether and acetone) by evaporation or vacuum distillation, are poured into a distillation flask.
1. A 2 L distillation flask is installed onto a magnetic stirrer with a heater.
2. Aqueous methamphetamine hydrochloride solutions 300 g with side products, obtained from the mother liquids after removal of organic solvents (ether and acetone) by evaporation or vacuum distillation, are poured into a distillation flask.
Note: Mother liquors and methamphetamine hydrochloride are got from previous methamphetamine synthesis different stages.
[Optional step] The aqueous methamphetamine solution can be filtered through a filter paper.
3. A concentrated solution of sodium hydroxide (NaOH 100 g in water 200 ml) is prepared.
4. Water 500 ml is poured into a 1 L three-necked flask, installed on an electric stove.
4. Water 500 ml is poured into a 1 L three-necked flask, installed on an electric stove.
Note: The three-necked flask performs the function of a steam generator. Steam is supplied into the distillation flask through a PTFE hose.
5. After complete methamphetamine solution addition to the distillation flask, the alkali solution is then poured in.
Note: A methamphetamine free base is formed.The distillation flask should be filled with water up to half.
6. A distillation flask stirrer and heaters of both flasks are turned on.
7. pH of the reaction mixture (RM) is measured. RM has to be alkaline (pH 11-12).
8. The distillation system is assembled with subsequent methamphetamine free base steam distillation.
7. pH of the reaction mixture (RM) is measured. RM has to be alkaline (pH 11-12).
8. The distillation system is assembled with subsequent methamphetamine free base steam distillation.
Note: Distillation is carried out until the last oily drops from the condenser. The condenser have to be supplied by a cold water flow.
9. The pure methamphetamine free base with water is collected in the receiving flask. Residues in the distillation flask have to be disposed.
10. The obtained distillate mixtures (in the two flasks: 250 ml and 1 L) are separated by a separatory funnel. The upper necessary layer is amine. Distillate mixtures have to be separated carefully. The lower aqueous layer can be used in the distillation flask for next methamphetamine free base distillation batches.
10. The obtained distillate mixtures (in the two flasks: 250 ml and 1 L) are separated by a separatory funnel. The upper necessary layer is amine. Distillate mixtures have to be separated carefully. The lower aqueous layer can be used in the distillation flask for next methamphetamine free base distillation batches.
Note: As an alternative method (for large scale syntheses), the distelled methamphetamine free base can be extracted from water mixture using dichloromethane or benzene with subsequent evaporation of the extractant in a rotary evaporator.
11. The methamphetamine free base yield after distillation is 164.99 g.
Dextromethamphetamine Hydrochloride Synthesis
12. Methamphetamine free base racemate 105.69 g (131.85 g of hydrochloride salt) is in the first beaker.
13. d,l-Tartaric acid 128 g is in the second beaker.
14. Ethanol 88% 700 ml is in the third beaker.
15. d,l-Tartaric acid 128 g is placed in a 1 L flask. Ethanol 88% 700 ml is added into the same vessel.
16. Then, methamphetamine free base racemate 105.69 g is poured into the flask. A stirrer and heating are switched on.
17. RM is completely dissolved and boiled in the flask with a reflux condenser for 1 h.
18. Then, the methamphetamine tartrate solution is hot filtered through a folded filter paper and left for crystallization. d-Methamphetamine l-tartrate starts is crystallized almost instantly.
19. RM is cooled to room temperature.
20. [Optional step] Simone's methamphetamine qualitative reaction is carried out. A d-methamphetamine l-tartrate sample is placed on a watch glass. An aqueous sodium bicarbonate solution drop is added to the sample in order to make alkaline pH. Then, a drop of sodium nitroprusside aq. solution is added. Next, a drop of acetic aldehyde solution in ethanol (1:1) is added. The blue color appearance is a sign that only methamphetamine is presented in the sample. The color saturation means the methamphetamine concentration in the sample. The lighter color, the less methamphetamine is in the sample. This qualitative reaction isn't suitable for amphetamine testing.
21. d-Methamphetamine l-tartrate sediment is carefully filtered using a Schott filter and vacuum filtration tools. l-Methamphetamine d-tartrate is left in the mother liquor.
22. A sodium hydroxide solution is prepared. Sodium hydroxide 100 g is dissolved in water 150 ml.
23. The alkali solution is added to the d-Methamphetamine l-tartrate sediment for dextromethamphetamine free base formation.
23. The obtained emulsion is poured into a separatory funnel and allowed to separate into layers for about 1 h.
24. The upper d-methamphetamine free base layer is remained in the funnel, the lower layer is discarded.
Dextromethamphetamine Hydrochloride Synthesis
12. Methamphetamine free base racemate 105.69 g (131.85 g of hydrochloride salt) is in the first beaker.
13. d,l-Tartaric acid 128 g is in the second beaker.
14. Ethanol 88% 700 ml is in the third beaker.
15. d,l-Tartaric acid 128 g is placed in a 1 L flask. Ethanol 88% 700 ml is added into the same vessel.
16. Then, methamphetamine free base racemate 105.69 g is poured into the flask. A stirrer and heating are switched on.
17. RM is completely dissolved and boiled in the flask with a reflux condenser for 1 h.
18. Then, the methamphetamine tartrate solution is hot filtered through a folded filter paper and left for crystallization. d-Methamphetamine l-tartrate starts is crystallized almost instantly.
19. RM is cooled to room temperature.
20. [Optional step] Simone's methamphetamine qualitative reaction is carried out. A d-methamphetamine l-tartrate sample is placed on a watch glass. An aqueous sodium bicarbonate solution drop is added to the sample in order to make alkaline pH. Then, a drop of sodium nitroprusside aq. solution is added. Next, a drop of acetic aldehyde solution in ethanol (1:1) is added. The blue color appearance is a sign that only methamphetamine is presented in the sample. The color saturation means the methamphetamine concentration in the sample. The lighter color, the less methamphetamine is in the sample. This qualitative reaction isn't suitable for amphetamine testing.
21. d-Methamphetamine l-tartrate sediment is carefully filtered using a Schott filter and vacuum filtration tools. l-Methamphetamine d-tartrate is left in the mother liquor.
22. A sodium hydroxide solution is prepared. Sodium hydroxide 100 g is dissolved in water 150 ml.
23. The alkali solution is added to the d-Methamphetamine l-tartrate sediment for dextromethamphetamine free base formation.
23. The obtained emulsion is poured into a separatory funnel and allowed to separate into layers for about 1 h.
24. The upper d-methamphetamine free base layer is remained in the funnel, the lower layer is discarded.
A preparation for d-Methamphetamine Hydrochloride Obtaining
25. A three-necked 1 L flask with ammonium chloride (NH4Cl) inside, equipped with with ground glass joints and PTFE gas pipeline, is prepared for the hydrogen chloride (HCl) gas production.
26. d-Methamphetamine free base is dissolved in diethyl ether (Et2O) (1:1) and solution is poured into a beaker.
27. Sulfuric acid is added dropwise to the gas generator three-necked flask.
28. RM is saturated with HCl gas to acidic pH 5-6. A RM color is turned pink.
29. The solution is cooled. d-Methamphetamine hydrochloride is crystallized.
30. Crystals are filtered using the Schott vacuum filtration.
31. d-Methamphetamine hydrochloride is dried to constant weight. The d-methamphetamine hydrochloride yield is 29.33 g.
26. d-Methamphetamine free base is dissolved in diethyl ether (Et2O) (1:1) and solution is poured into a beaker.
27. Sulfuric acid is added dropwise to the gas generator three-necked flask.
28. RM is saturated with HCl gas to acidic pH 5-6. A RM color is turned pink.
29. The solution is cooled. d-Methamphetamine hydrochloride is crystallized.
30. Crystals are filtered using the Schott vacuum filtration.
31. d-Methamphetamine hydrochloride is dried to constant weight. The d-methamphetamine hydrochloride yield is 29.33 g.
Note: The qualitative Simon's reaction shows a high d-methamphetamine concentration in the sample.
Recrystallization of d-Methamphetamine Hydrochloride
32. d-Methamphetamine hydrochloride 29.33 g is dissolved in 88% ethanol (100 ml + 70 ml for residues rinsing) in a beaker.
33. The obtained solution is filtered through a filter paper.
34. Then, RM is evaporated at room temperature to 100-120 ml volume.
35. After evaporation, the beaker with this solution is put into a freezer at -4 °C for 10 h.
36. The obtained crystals should be quickly filtered and dried on the filter.
33. The obtained solution is filtered through a filter paper.
34. Then, RM is evaporated at room temperature to 100-120 ml volume.
35. After evaporation, the beaker with this solution is put into a freezer at -4 °C for 10 h.
36. The obtained crystals should be quickly filtered and dried on the filter.
Note: Methamphetamine has a high solubility in alcohol, so that it is not washed with additional portions of solvent during filtration.
37. The mother liquor is left for a cold crystallization.
38. The d-Methamphetamine hydrochloride recrystallization yield is 20.23 g.
38. The d-Methamphetamine hydrochloride recrystallization yield is 20.23 g.
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