Where do you think I might be wrong?

[khrishnapada]

Methamphetamine synthesis from P2P by NaBH4 reduction. Medium-Scale.

Introduction I represent to BB audience Methamphetamine synthesis method of 1-phenyl-2-propanon (P2P) reductive amination by NaBH4. Following method allows obtaining and large batches of product. The hardest problem of this method is the heat generating during exothermic reaction of imine...

bbgate.com

I followed this method. But I haven't been successful yet. I don't know why. I'm sure about my methylamine 40% solution and I have no doubt about sodium borohydride either. The problem is with Phenylacetone/P2P. I would like your advice on this matter and Is the method I followed correct or should I follow some other method? I added hydrochloride gas after distillation. But my reaction mixture did not convert into hydrochloride salt.

 

[Osmosis Vanderwaal]

The 40% methylamine. You need to gas that out to alcohol or deprotonate methylammonium chloride to alcohol. 40% methylamine is 60% water and you need to have ABSOLUTELY NO WATER in this synth

 

[khrishnapada]

I have used anhydrous magnesium sulfate, anhydrous sodium sulfate, and dry silica gel in both the methanol and IPA processes. Isn't that enough?

 

[Idontcarethatmuch]

You can not dry 60% water with mgso4 or another drying agent

 

[khrishnapada]

Please give a hands on work up process?

 

[Idontcarethatmuch]

One way

Take the 40 % aqueous methylamine solution.
Add a strong base (e.g. solid NaOH or KOH) – about 1.5-2 mol equivalents per equivalent of CH₃NH₃⁺ (remember you just got 40%).

Stir slowly under gentle heating (~40–50 °C).
The free CH₃NH₂ escapes as a gas — it is highly volatile (b.p. −6 °C).
Pass the released vapor through a gas inlet (ie gas washing bottle) directly into a vessel with dry methanol, cooled to 0 °C.

The gaseous CH₃NH₂ dissolves very well in the cold MeOH.
In this way, you obtain a clear, low-water (dry it anyway) methanolic solution of the base.

Use a closed apparatus and ventilation anyway methylamine is toxic and smells very bad

 

[khrishnapada]

Thanks a lot sir. Great and extremely helpful.

 

[Idontcarethatmuch]

Edit

 

[Osmosis Vanderwaal]

Another, more clandestine method involves methylamine hcl, which is a solid and adding it and a strong base to some non-polar solvent of your preference. In many invantations it can be done in vivo, ie in the reaction mixture directly making some reactions one-pot methods ( like shake and bake meth)