Hello,
After many tests using Methylamine HCL based on this method I will share the best way that I found to obtain Methamphetamine freebase in big scale:
- Fill the reactor with the 14 L of Methanol
- With stirring dissolve the Methylamine HCL
- Put the reactor temp at 0C(not the mixture temp) and add the NaOH, the temp will increase
- Once the temp come back to 20C add the P2P, the temp will increase stir it during 45min-1 hour
- Add 252gr of anhydrous sodium sulfate
- When the mixture temp arrives to 8C start adding portionwise the NaBH4 not exceeding the 20C
- Once all the NaBH4 has been added let it mixing under 20C during aprox 2 hours until the mixture stops bubbling
- Add the water and continue mixing during 5 min
- Add the DCM and mix it during 10 min
- Stop stirring and let layers get separated
- Keep the bottom layer and discard the upper one( not profitable to extract this aqueous phase)
- Add 200gr of anhydrous sodium sulfate to the saved layer and mix it
- Filter it in Buchner Funnel
- Evaporate the DCM
- Clean and smelly Methamphetamine freebase obtained
;-)