Isomerization - Aluminium chloride

[Cannabin]

Hello
I did not find clear information on the forum about isomerization - with aluminum chloride. I only know that the temperature should be low and the reaction takes 30 minutes. How much % aluminum chloride should be used relative to CBD?

[cyclopath]

Talk to @EagleChem

@EagleChem

You should use 5% alcl3 in .33:1 DCM:CBD. Everything is going to turn red don’t panic. Let this run around 0C for 30 minutes. You will see exotherm but it is fine with 0C. 30minutes done now it’s time to work up. You need to precipitate salt out without forming a bunch of HCL gas. The work up is where the fun really begins. Also remember that no matter how hard you hit that LLE you need a final step to ensure everything is clean and you don’t go straight to d8 during distillation. It will be slow to separate. That’s normal. Be very patient with your clean up. it pays off. By the time you hit the rotovap for solvent recovery you will have a golden oil. 92+%. Send me a message if you want to talk about it further.

Can you explain how to “precipitate salt out without forming a bunch of HCL gas”?

[Cassin]

@cyclopath

“precipitate salt out without forming a bunch of HCL gas”?

You know… anytime I want to get a precipitate without making a bunch of uncaptured HCL gas… I just bubble that gas through some water - which makes some liquid HCL by capturing that gas in the water… which I can then do other things with.

My personal experiences with aluminum chloride have been unpleasant - one of my biggest lab disasters was using this. Haha. Also - DCM is NASTY. And halogens are NASTY.

And that’s generally a lot of unwanted hazardous halogenated waste.

So you know. I would totally not go that way at all, if I had any other option. But that’s just me.

Also - keeping exothermic reactions cold… can be complicated. Do please try not to kill yourself randomly. If you can’t do the half reactions and stoichiometric calculations to figure out how much you think you need… then you might be doing chemistry that is dangerous without appropriate educational or experience based background.

Please don’t hurt yourself. <3

[Cannabin]

Hi
I made the CBD- AlCl3 reaction . I mixed the dried CBD isolate with the dried DCM 1:1 ( 100g CBD+100ml DCM). I cooled everything down to a temp of -4C . And I started to add 5% AlCl3 (5g) . I added AlCl3 very slowly keeping an eye on the temperature . After adding all the AlCl3 I stirred for 45 minutes . Then I began to add slowly a 15% sodium hydroxide solution ( 30 g sodium hydroxide + 170 ml demineralised water ) . I added very slowly keeping an eye on the temperature . After adding about 1/4 of the soda solution the colour changed to golden , but after adding the rest of the solution everything turned dark red . What went wrong ?

[Aurion]

Maybe I’m wrong, but wouldn’t you stop adding the hydroxide once the PH was neutral?

You may have over shot your desired PH.

I’m not a chemist though. Lol.

[Cannabin]

Well that’s what I thought too . I just wanted to make sure

[Cannabin]

Once the reaction is complete, can I neutralise the AlCl3 using sodium bicarbonate instead of sodium hydroxide ? And once neutralised, start the rinsing immediately?