Interesting patent recently published on Cannabinol production

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Newish member here, wanted to share thoughts on an interesting patent application from China published recently on the alleged conversion of CBD to CBN. I am skeptical especially since the patent claims no THC intermediate, but would like to hear the community’s thoughts on viability. Another odd note is how low/mild conditions are for what traditionally seems to be a very unfavorable rxn. Not really sure why these authors would go through a patent filing process for something that doesn’t work though.

Patent TLDR: copper (I) bromide + O2 + THF at 90C converts CBD to CBN in relatively good reported yield.

CN114853711A - Method for preparing cannabinol by copper catalysis one-pot method - Google Patents

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I would literally become a monkey’s uncle if DDQ yielded 70-85% conversion to CBN.

I have a hard time believing some of their stated yields/results due to my own experiences in lab running identical or similar reactions, which makes me cautious to believe any of the stated yields. If any one particular claim has been embellished, then it stands to reason that they have all been embellished.

Nonetheless, pretty low-stakes work for someone to repeat for themselves - but there are less gnarly ways to get better yields.

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Hmm what’s the boiling point of THF ?
The reagents might work but not with these parameters

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I know its rhetorical question but its 66C at atm.

I’m confused by the TLDR though - there are many experiments listed…

CBD + PTSA + CuOAc2 + DDQ in toluene @ 100C + chromatography = 86% CBN Super dehydrogenation = oxidation plus extra catalyst, because reasons!

CBD + PIDA + CuOAc2 in xylene @ 120C + chromatography = 84% CBN i’m still working through the reaction mechanism on this one… there’s so many things that could be made… this is why we have so many unknowns, right?

CBD + CuBr2 + H2O2 in ACN @ 80C = 72% tickling by brain - so many mols of H2O2… and we know that CBd inhibits the ability of H2O2 to do its work…would the CuBr2 be enough of a catalyst to overcome the natural antioxidative nature of CBD…

CBD + CuOAc2 + DDQ in THF @ 100C = 83% CBN close to the TLDR? again with the intense catalyzised oxidation, how ever are they keeping all the impurities from jumping in?

CBD + PTSA + CuCl2 in toluene @40C = 75% CBN this one I thought was interesting as it is the only one that mentions the specific pressures related to the experiments

CBD + CuCl + DDQ in DMSO @ 100C = 85% CBN is this a typo? how would these electrons move through dehydrogenation…and if so why wouldn’t more impurities be produced… they would but perhaps they are not counting all the impurities in general the HUGE amount of reagents and catalysts vs starting materials seems like it would be a horrible WASTE of resources…

CBD + PTSA + CuI in DMF + O2 @ 60C = 84% CBN more and more expensive materials each experiment…

CBD + CuCl + DDQ in xylene @ 100C = 81% CBN at least this one seems like a reasonable course of action, if it works, regarding material costs at scale…

CBD + PTSA + CuOAc2 + DDQ in ACN @ 70C = 78% CBN does anyone else wonder why they keep switching the nomenclature around for DDQ? I mean why go between different naming conventions…its like the experiments were written by totally different people…and no one did any peer review or anything at all

I think its interesting that they talk about this process as low cost. Lower than…natural degradation of THC into CBN? Lower than utilizing UV Light? Lower than utilizing other cheaper acids?

It also seems a bit weird that they call this a one-pot solution, when clearly the experiments would require multiple pots - including at least separate vessels for chromatography. How can you call that one-pot when you are using like 6 pots?

Such is life I suppose in patent submissions.

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I ll try this with cbd-a at 24 hours
To make cbn-a
Cbd-a is a gnarly molecuul to get to move in rxns the A somehow protects it
Cbd-a with ptsa at 40 takes hours to get a little isomerization

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Did you even used pure CBDA, or partly decarbed ?
Maybe what isomerized in your experiment was the decarbed portion… :thinking:

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I have a CBNA synthesis but never really met anyone with any interest, but it starts with THCA rather than CBDA - which ultimately simplifies matters.

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Anyone else roll their eyes when they said it was out of China?

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Who knows maybe although my starting material is 99.7% cbd-a in the cooh form
@moronnabis ( I am learning :laughing:)
Planning on some runs in the coo form to check for diffrances
As for reagents tried so far
Triisobutyl works
Ptsa doesn’t really a whole lot of unknowns
Camfor sulfonic same story as ptsa
Alcl3 makes things move to a whole lot of unknowns
Indeed all COa s have a large amount of cbd
(Decarbed) like 4-6% and never is the reaction over 40 C

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interesting stuff. When you say “Triisobutyl”, you are referring to Triisobutyl what? Phosphate? Aluminium?

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Triisobutylaluminium 1molar solution in hexane

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