In the name of open source (CBN sulfur dehydrogenation procedure 1968)

This synthetic route was published in 1968 and some minor optimizations can make your life easier if you know a thing or two about practical organic chemistry. Enjoy :wink:

From THC to CBN:

“Dehydrogenation was carried out in all cases by warming the compound with sulfur at 200°, under nitrogen, in a distillation finger for ca. 1 h, by which time evolution of hydrogen sulfide slowed down considerably. The material was then distilled and the distillate, containing sulfur, was taken in pentane and filtered through 1 - 2 gr of alumina. Cannabinol (XI) [6] was the main compound obtained, as evidenced by TLC, IR and VPC (some starting material remained in all cases).”

gaoni1968 iso-thc.pdf (1.0 MB)


Nice. Added to the data dump, in the name of open source.

This is not a SOP though. That’s a small part of the value we add through the GLG, @wcruces15 replicated this process, refined it, then made it digestible for the average laymen like me. We then standardized the formatting to add it to our ready to go deck of SOPs.

You don’t pay for knowledge in the gang, that’s free here. You are paying for the time and effort fellow community members have put into SOPs and their own professional development, whether that be through building companies to supply needs or individuals looking to further their networking.

That money goes back into the gang in the form of meetups and purchased SOPs, as well as this site


Let me see if I can find the 2 articles regarding sulphur for this.


Here’s one of the ones you’re thinking of:

85007d52ba809399f6d4211c460abe8943ce.pdf (7.1 MB)


This book is all theory and there is no experimental data. You’ll need to take it and cite forwards to find anything useful.


It’s not only theory, they go over the procedural data as well…


So this is not enough to run a reaction. Why reinvent the wheel when the process has been created. Take a reported method and tweak it.


This :metal:t3:


I’m not saying reinvent the wheel. I read that and it helped me understand the process a little. I’m not saying it’s an SOP.


I feel compelled to warn people against attempting this reaction, especially at any large scale. I have worked with hydrogen sulfide (the byproduct of this reaction) in the past, and it is known for its low level toxicity. It is uniquely hazardous because it causes ‘nose blindness’ (olfactory paralysis) at low concentrations (~100ppm), resulting in inability to recognize the buildup of the toxic gas. Not long after losing the ability to smell respiratory paralysis sets in, followed by death (a lasting medical condition).

Be safe out there,


Anyone attempting this should have no issues since we all work with proper ventilation and PPE, right guys? When designing an experiment, it’s important to write down every reagent, products/byproducts and reasearch and list the potential hazards in your laboratory notebook, so you are aware of the risks involved.

Follow a format like this:

If you don’t already do this, then yeah please don’t try it.

But it’s a free country, if grandma wants to synth up some CBN then she has the liberty to do that… as long as she fries her OWN olfactory senses doing it and NO ONE else is bothered, I see no issue.


Yes please reach out to the chemists on here for any advice on how to run this process.


Sorry, but this made me LOL


What precautions should be taken in addition to working in a fume hood?

1 Like

Is there an off the shelf sensor for this substance that reads the ppm level and alarms at proper % of exposure limit?


Many are available


Yep just said it was a procedure, not a standard operating procedure. I can rewrite it and compile it into a nice platter and transfer the info via spoon. The chemistry spoons in my household are plentiful. :smiley:

Here’s another THC–>CBN procedure utilizing sulfur from 1940:

Dehydrogenation of Tetrahydrocannabinol to Cannabinol.—-
“A mixture of 2.82 g. of tetrahydrocannabinol ([α]32D —167°) and 0.58 g. of sulfur
in a side-neck test tube was heated at 240-250° until evolution of
hydrogen sulfide had ceased (about twenty minutes). After cooling
to 180-190°, the product was distilled in vacuo onto a cold
finger. The resulting material was taken up in about 25
cc. of petroleum ether (b. p. 30-60°) the solution cooled
and scratched, About 0.5 g. of crude cannabinol was
thus obtained. On further purification from the same solvent,
it gave white crystals, m. p. 75-76° (cor.) identical
in all respects with an authentic sample of cannabinol.”

full paper: adams1940 iso.pdf (427.6 KB)

1 Like

Do it and drop it here for free, that’d be great. Or, the GLG will buy it from you if cash is more valuable to you than clout


Worth every penny.

Word. Cash over clout any day of the week.

But I’ll be posting plenty of goodies to the forum in the months and years ahead :wink: