Methamphetamine Synthesis from Ephedrine by Using I2 and H3PO2

[GhostChemist]

Starting Reagents and Materials​

• 6 g Synthetic ephedrine hydrochloride racemic​
• 12 g I2​
• 10.8 ml H3PO2 (50%)​
• 20 ml H2O​
• 50 ml 25% NaOH (15-20 г NaOH)​
• 3 g sodium thiosulfate​
• 250-300 ml DCM​
• 30-50 g Na2SO4​
• 100 ml Petroleum ether​
• HCl gas​
• 100 g NH4Cl​
• 25 ml H2SO4 83%​
• Flasks 250 and 500 ml
• Glasses
• Funnels
• Separating funnel
• Magnetic stirrer with heating
• Flask heater
• Reflux
• Paper filters
• Pipettes
• Porcelain filter for vacuum filtration
• Chen's reagents
• Simon's reagents
• pH indicator paper

The process way presented on Scheme 1.

Starting reagents for meth synthesis: synthetic ephedrine hydrochloride, I2 and H3PO2. Fig. 1

Ephedrine hydrochloride ground into a powder in a mortar. Fig 2​

​

The powder of Ephedrine hydrochloride is poured into the flask. Fig 3

I2 is ground into a powder. Fig 4​

​

The powder of I2 is to the Ephedrine hydrochloride in the flask and continuously mixing. Fig 5

The H3PO2 is added in portions to the mixture in the flask while continuously mixing. Fig 6

The reaction is very intense. Reflux connected to the flask. Fig 7

The following portions of acid are added after the cessation of the vigorous reaction. Fig 8

The mixture is heated at a temperature of 100-160°C for 10-12 hours. Fig 9​

The solution should become transparent and homogeneous. Fig 10

To the resulting reaction mixture, 15-20 ml of water is added. Fig 11

NaOH solution is added to the RM until reaching an alkaline pH. Fig 12

Next, sodium thiosulfate solution is added. Fig 13

The mixture cooled and added 100 ml of DCM (boiling point of DCM is 40°C). Fig 14

The mixture is transferred to a separating funnel. DCM is separated. Additionally, 2-3 extractions of DCM are carried out with portions of 40-50 ml each. Fig 15​

The layer of DCM is dried with sodium sulfate. Fig 16

The DHM is distilled at a temperature of 90-110°C until the distillation of DCM ceases. Additionally, sodium sulfate is washed with new portions of DCM. Fig 17

To the obtained oil, 30+30 ml of petroleum ether is added. Fig 18

The solution is filtered through a paper filter. Fig 19

Impurities is in the distillation flask and on the filter. Fig 20

Solution of methamphetamine in petroleum ether is saturated with gaseous hydrogen chloride until reaching an acidic pH. Hydrogen chloride is generated by adding sulfuric acid to ammonium chloride. Fig 21​

The precipitated meth hydrochloride is filtered. Fig 22

Simon's reaction with meth hydrochloride is positive (blue coloring); Chen's reaction is negative; Chen's control on a clean sample of ephedrine is positive. Fig 23

The filtered meth hydrochloride precipitate is dried on the air. Fig 24

Yield is 4.24 g or 77.1 %

 

[hacke8]

Thank you very much for sharing. Another classic preparation thread creates a perfect stage for newcomers.

 

[hacke8]

There are a few simple questions, 1: Is it possible to use 99% hypophoric acid? 2: What is the best specific reflux temperature? 3: What catalyst can be added to speed up the reaction without waiting for 10-12 hours. 4: When evaporating DCM, can you filter sodium sulfate first to operate the next steps?

 

[GhostChemist]

There are a few simple questions, 1: Is it possible to use 99% hypophoric acid? 2: What is the best specific reflux temperature? 3: What catalyst can be added to speed up the reaction without waiting for 10-12 hours. 4: When evaporating DCM, can you filter sodium sulfate first to operate the next steps?

hacke81. yep
2. 100-160 C
3. Now process without catalysts (may be in future)
4. not understand this question

 

[hacke8]

Gentlemen, I did this experiment, and I heated it to 125 degrees, because phosphoric acid is heated to 130 degrees, there will be phosphate hydrogen gas (toxic). Is there any way to avoid these?

 

[billythekid]

Gentlemen, I did this experiment, and I heated it to 125 degrees, because phosphoric acid is heated to 130 degrees, there will be phosphate hydrogen gas (toxic). Is there any way to avoid these?

hacke8It is Hypophosphorous acid and heating the reaction mix above 110 results in higher amount of impurities and is dangerous you do not want to decompose the hypo high risk of fire explosion and poisoning patience in important here

 

[hacke8]

It is Hypophosphorous acid and heating the reaction mix above 110 results in higher amount of impurities and is dangerous you do not want to decompose the hypo high risk of fire explosion and poisoning patience in important here

billythekidYes, sir, I use 50% of H3PO2, and the perfect temperature is within 110 degrees, right?

 

[billythekid]

Yes, sir, I use 50% of H3PO2, and the perfect temperature is within 110 degrees, right?

hacke8110 degrees Celsius is best i find but it decomposes at 130 degrees into phosphine gas (spontaneously combustible) and phosphoric acid, for having the reflux condenser sealed is not a good idea, for smaller reactions you can put a baloon over the top to help keep the hydroiodic gas in,

 

[hacke8]

It is Hypophosphorous acid and heating the reaction mix above 110 results in higher amount of impurities and is dangerous you do not want to decompose the hypo high risk of fire explosion and poisoning patience in important here

billythekidYes, sir. I also installed two large balloons on the condenser to place the volatilization of iodine. How long does it take to complete the conversion of methyl at 110 degrees?

 

[GhostChemist]

Gentlemen, I did this experiment, and I heated it to 125 degrees, because phosphoric acid is heated to 130 degrees, there will be phosphate hydrogen gas (toxic). Is there any way to avoid these?

hacke8you can use the absorption of PH3 with NaClO and NaOH
H3PO2 destroyed at 170 C

 

[hacke8]

you can use the absorption of PH3 with NaClO and NaOH
H3PO2 destroyed at 170 C

GhostChemistHi, sir, this damn translation, I don't understand what you mean. Do you mean what kind of sodium or something else? How to operate? Thank you for your answer.

 

[Mr.blank00]

Hello sir, is the top cover of the condenser opened or closed when refluxing for 10-12 hours, and is ice water used to cool the condenser, because if you just heat it without a condenser for 12 hours the solution will evaporate and dry, please explain.

 

[hacke8]

Hello sir, is the top cover of the condenser opened or closed when refluxing for 10-12 hours, and is ice water used to cool the condenser, because if you just heat it without a condenser for 12 hours the solution will evaporate and dry, please explain.

Mr.blank00Hi, do you know why it's called a condenser instead of another name?

 

[GhostChemist]

Hello sir, is the top cover of the condenser opened or closed when refluxing for 10-12 hours, and is ice water used to cool the condenser, because if you just heat it without a condenser for 12 hours the solution will evaporate and dry, please explain.

Mr.blank00reflux condenser must be opened or covered with a piece of cotton wool soaked in water

 

[hacke8]

Cold water is needed, the colder the better, as there is a possibility of explosion in the seal.

 

[ImRegistered]

Would this synthesis work with p2p ?

 

[hacke8]

Would this synthesis work with p2p ?

ImRegisteredNo, this is only suitable for ephedrine. P2P uses amalgam or other lines.

 

[ImRegistered]

No, this is only suitable for ephedrine. P2P uses amalgam or other lines.

hacke8Other then nabh4 or tinfoil, what other methods can I look into?

 

[hacke8]

Sir, I don't understand one step. Figure 17, DHM is distilled at 90-110 degrees. What is this DHM? Or can it be distilled directly at 40 degrees without flowing out?

 

[ImRegistered]

Sir, I don't understand one step. Figure 17, DHM is distilled at 90-110 degrees. What is this DHM? Or can it be distilled directly at 40 degrees without flowing out?

hacke8Dcm