Procedure:
Creating ritalinic acid from Ethylphenidate:
1. For every 100mg ethylphenidate, add 1mL (1000mg) of water. Then add HCl, about 20mg HCl (pure). Calculate for solution (29% HCl -> about 60mg HCl). Adding more HCl will speed up the reaction process, but you risk burning your product when evaporating the water.
2. Let the solution sit for about 20h @ 40°C. Let the solution evaporate at the mean time. This temperature is needed for a higher yield (the ethanol that comes free evaporates, shifting the reaction in the production of ritalinic acid). Focus on the liquid and add water to it when it comes to low. Do this for about 4h and then you can put a cap on it so it doesn't evaporate anymore, and do the remaining 16h's.
3. Extracting the ritalinic acid: Slowly add NaOH to the solution to neutralize the HCl. The concentration is critical. To less and there will be HCl left in the solution, to much and your ritalinic acid will convert to freebase. So aim for a little HCl left in solution. See how much HCl you added, then add an slightly less then equal amount of NaOH (in molar)
So 20mg pure HCl (=0,55mMOL) -> less then 22mg NaOH. 15 is fine. You will hear a sissing sound.
4. Continue to evaporate the solution at 40°C. When coming to an near end, let the solution continue to dry @ room temperature. This b/c the remaining HCl could become to concentrated and 'attack' the product. Slow evaporation allows the HCl to evaporate with it.
5. Collect your ritalinic acid.
Converting ritalinic acid to methylphenidate:
1. For every 100mg of ritalinic acid, add 1000mL methanol and 20mg pure HCl. If u use HCl in an aqua solution, there will be water in the solution, reducing yield. But there is a way around this.
2. Set the temperature of the liquit @ 40°C. Important is here that the temperature does not go higher, or HCl will react with Methanol, creating more water, reducing yield. Let the solution evaporate. And continue to add Methanol to it to so the solution won't dry out. Water will evaporate with the methanol, so - by adding methanol - the water % will go down, increasing yield.
3. Do this for about 20h. Longer if you have a lower temperature (room temp = 72h). After 4h @ 40°C the conversion is 88% complete.
4. Extraction. Let the methanol evaporate till there is approx 50% left. (no more then 40°C!! use vacuum for faster evaporation)
Then add double this amount of isopropyl alcohol.
Isopropyl alcohol is here the anti-solvent, forcing the Methylphenidate out of solution.
Let it evaporate, and when it's at 50% again, add more isopropyl alcohol. The methanol (solvent) will evaporate more quickly then the isopropyl alcohol b/c of the lower boiling point.
When it's at 50% again, put the solution into the freezer. (2°C or lower = good). This will force more Methylphenidate out of solution.
5. Filter the liquid. This step did not work very well for me, as my filter wasn't good, and the amount of powder (260mg) was low. So use a good filter! Not a coffee filter!
Collect the residue. Let it dry.
If you want it more pure, wash with isopropyl alcohol or acetone.
Note:
Very bad (and destroying your product) is fast evaporation of the solution with HCl present. Concentration of HCl will increase, and your product will burn. It will become grey/green/black.. Should be pure white to little yellow.
EDIT: For all those interested:
I used pH paper this time, to set the pH between 1 - 2. I used lots of water. During the evaporation, I monitored the pH. When it dropped to low, I added a drop of NaOH to increase the pH. After 20h I neutralized the pH (to about 4-5, so it's slightly acidic).
Then I let it fully evaporate. This time, the product isn't yellow, it's pure white. Looks lots better then before.
So before, I allowed the acid to become more concentrated during evaporation. And this must of caused a damage to the product..
Product still worked, but I guess at less potency then the batch I'm going to have now