I made an error in preparing methamphetamine using the Grignard reaction.

[）d7289hdm]

Hello, I encountered a problem when performing a Grignard addition reaction between the product of the addition of methylamine and acetaldehyde and benzyl magnesium chloride. I'm certain that methamphetamine was formed, but after inhaling it, my throat felt very uncomfortable, like a burning sensation, which was very unpleasant. I subsequently used ammonium chloride to quench the reaction. I don't know why. Could someone please help me?

 

[）d7289hdm]

I used ethanol recrystallization, but I still felt a stinging sensation after applying the hot compress

 

[William Dampier]

https://www.erowid.org/archive/rhodium/chemistry/grignardimine.html

Are you talking about this route? Do you have details and photos of your synthesis? We are well-acquainted with Grignard reactions in practice, and we might be able to help.

 

[）d7289hdm]

Yes, this is my synthesis route. Figure 1 shows the result at minute 5 after adding acetaldehyde and methylamine. Figure 2 shows the result at minute 30

 

[William Dampier]

Are you using methylamine hydrochloride? I don’t fully understand how, in this method, the methylamine hydrochloride should condense with acetaldehyde to form an imine. It’s more likely you need to generate methylamine gas (by displacing it with sodium hydroxide from an aqueous solution of methylamine) into a diethyl ether or THF (depending on what you used for the organomagnesium), with the aldehyde dissolved and an drying agent present. Then, use the pre-prepared methylimine for the reaction.

 

[）d7289hdm]

I am using a THF solution of methylamine.